Medicine – Primary Hyperlipidaemia Disorders

Primary hyperlipidaemias are inherited disorders of lipoprotein metabolism that cause abnormal elevation of LDL cholesterol, triglycerides, or both. They are important because they can lead to premature atherosclerotic cardiovascular disease, pancreatitis, or characteristic lipid deposits such as xanthomas.

The major disorders in the original notes are familial hypercholesterolaemia, familial hypertriglyceridaemia, lipoprotein lipase deficiency, and familial combined hyperlipidaemia.

1. Familial Hypercholesterolaemia

Familial hypercholesterolaemia – FH is an inherited disorder characterised by markedly elevated:

LDL cholesterol.

The classic form is usually inherited in an:

Autosomal dominant pattern.

2. Genetic Basis of Familial Hypercholesterolaemia

Most classical cases are caused by pathogenic variants affecting the:

LDL receptor – LDLR.

Other genes can also produce a similar phenotype, including:

APOB

and

PCSK9.

The underlying problem is impaired removal of LDL particles from the circulation.

3. LDL Receptor Defect

Normally LDL particles bind to:

LDL receptors on hepatocytes

and are removed from the blood.

When LDL receptor function is reduced:

LDL clearance falls.

Therefore LDL remains in the circulation for longer.

This leads to:

Markedly elevated plasma LDL cholesterol.

So the original statement that the LDL half-life is prolonged is broadly correct.

4. Heterozygous Familial Hypercholesterolaemia

A person with one affected allele typically has:

Heterozygous familial hypercholesterolaemia – HeFH.

The original prevalence of:

About 1 in 500

is an older traditional estimate.

Modern population studies suggest HeFH is more common, approximately:

Around 1 in 200–300 people, though prevalence varies between populations.

5. Cholesterol Levels in Heterozygous FH

The original notes give total cholesterol of:

9–15 mmol/L.

Patients with HeFH can indeed have very high cholesterol, but a fixed range is not required for diagnosis.

More important is:

Markedly elevated LDL cholesterol, especially from a young age, together with family history or physical signs.

6. Cardiovascular Risk in Heterozygous FH

Untreated HeFH greatly increases the risk of:

Premature atherosclerotic cardiovascular disease.

This includes:

Coronary artery disease.

Myocardial infarction.

The exact relative risk varies, so the older statement of a universal:

“six- to eightfold increase”

should be regarded as an approximate historical teaching point rather than a fixed figure.

7. Tendon Xanthomas

One of the most characteristic clinical signs of FH is:

Tendon xanthomas.

These are cholesterol deposits within tendons, especially:

Achilles tendons.

Extensor tendons of the hands.

They strongly suggest:

Familial hypercholesterolaemia.

8. Xanthelasma

Xanthelasma refers to yellow cholesterol-rich plaques around the eyelids.

It may occur in FH, but it is:

Less specific than tendon xanthomas.

Xanthelasma can also occur in people without severe inherited hypercholesterolaemia.

9. Corneal Arcus

Another possible feature is:

Corneal arcus.

In older adults this can be physiological, but in a young person it may support the presence of:

Severe hypercholesterolaemia.

10. Homozygous Familial Hypercholesterolaemia

Homozygous familial hypercholesterolaemia – HoFH is much rarer and far more severe.

Patients have profoundly impaired LDL receptor pathway function.

This results in extremely high LDL cholesterol from:

Early childhood.

11. Childhood Xanthomas

The original notes correctly describe:

Xanthomas in early childhood.

Children with HoFH can develop widespread xanthomas because cholesterol levels are extremely high from birth.

Sites may include:

Tendons.

Skin.

Pressure areas.

12. Childhood Cardiovascular Disease

Untreated HoFH can cause severe atherosclerosis very early in life.

Complications may include:

Aortic root disease.

Coronary artery disease.

Myocardial infarction during childhood or adolescence.

Therefore HoFH is a severe medical condition requiring specialist treatment.

13. Familial Hypercholesterolaemia and Atherosclerosis

The central complication of FH is accelerated:

Atherosclerosis.

Persistently high LDL penetrates the arterial wall, contributing to plaque development and progressive narrowing or plaque rupture.

This explains why reducing LDL exposure as early as possible is a major goal in FH.

14. Treatment of Familial Hypercholesterolaemia

The original notes correctly include:

Diet

and

HMG-CoA reductase inhibitors – statins.

However, modern treatment is usually more intensive than diet plus statin alone.

Lifestyle measures remain useful, but genetic FH generally cannot be adequately treated by dietary modification alone.

15. Statins

Statins inhibit:

HMG-CoA reductase

in the liver.

This reduces hepatic cholesterol synthesis and increases hepatic expression of:

LDL receptors.

Therefore:

STATIN → ↑ LDL RECEPTOR ACTIVITY → ↓ PLASMA LDL.

High-intensity statin therapy is commonly a cornerstone of treatment.

16. Additional LDL-Lowering Therapy

If LDL remains elevated despite maximally tolerated statin therapy, additional agents may include:

Ezetimibe.

PCSK9-targeted therapy.

Other LDL-lowering treatments may be used in selected severe cases.

Patients with HoFH often need specialist treatment, potentially including more intensive pharmacological strategies and occasionally:

Lipoprotein apheresis.

17. Familial Hypertriglyceridaemia

Familial hypertriglyceridaemia is an inherited tendency toward elevated:

Triglycerides, usually carried mainly in VLDL particles.

It is often described as having:

Autosomal dominant familial clustering.

However, the genetics are usually more complex than a simple single-gene dominant disorder.

18. Turbid Plasma

When triglycerides are markedly elevated, plasma may appear:

Turbid or milky.

This is caused by large numbers of triglyceride-rich lipoprotein particles.

The more severe the triglyceride elevation, the more obvious the turbidity may become.

19. Eruptive Xanthomas

Severe hypertriglyceridaemia can cause:

Eruptive xanthomas.

These are small yellow-red papules, often appearing over:

Buttocks.

Back.

Extensor surfaces.

They can appear rapidly when triglycerides are extremely elevated.

20. Hypertriglyceridaemia and Pancreatitis

A major complication of severe hypertriglyceridaemia is:

Acute pancreatitis.

Risk increases substantially when triglycerides become very high.

Therefore:

SEVERE HYPERTRIGLYCERIDAEMIA + ABDOMINAL PAIN → CONSIDER ACUTE PANCREATITIS.

21. Hepatosplenomegaly

Very severe triglyceride-rich lipoprotein accumulation can produce:

Hepatomegaly

and sometimes:

Splenomegaly.

This is especially associated with severe chylomicronaemia syndromes rather than ordinary moderate familial hypertriglyceridaemia.

22. Retinal Changes

Severe hypertriglyceridaemia may produce:

Lipemia retinalis, where retinal vessels develop a creamy appearance.

The original note lists:

Retinal vein thrombosis.

Thrombotic events can occur in various metabolic settings, but lipemia retinalis is the more classic ocular association of extreme hypertriglyceridaemia.

23. Treatment of Familial Hypertriglyceridaemia

Treatment starts with:

Dietary modification.

Weight management.

Reduction or avoidance of alcohol.

Treatment of diabetes or other secondary contributors.

For significant persistent hypertriglyceridaemia, medications such as:

Fibrates

may be used.

24. Fibrates

Fibrates activate:

PPAR-α.

This increases fatty-acid oxidation and enhances metabolism of triglyceride-rich lipoproteins.

The overall effect is:

Lower plasma triglycerides.

Therefore:

FIBRATES → PARTICULARLY USEFUL FOR HIGH TRIGLYCERIDES.

25. Lipoprotein Lipase Deficiency

Lipoprotein lipase – LPL deficiency is a rare inherited disorder causing severe impairment of triglyceride-rich lipoprotein metabolism.

It is classically inherited in an:

Autosomal recessive pattern.

26. Normal Function of Lipoprotein Lipase

LPL is located on vascular endothelial surfaces, especially in:

Adipose tissue.

Skeletal muscle.

It hydrolyses triglycerides contained in:

Chylomicrons

and

VLDL.

This releases fatty acids for uptake into tissues.

27. LPL Deficiency

When LPL activity is severely deficient:

Chylomicrons cannot be cleared normally.

Therefore chylomicrons accumulate in plasma.

The result is:

Severe hypertriglyceridaemia.

This is part of the syndrome often termed:

Familial chylomicronaemia syndrome.

28. Clinical Features of LPL Deficiency

Patients may develop symptoms from childhood, including:

Recurrent pancreatitis.

Eruptive xanthomas.

Lipemia retinalis.

Hepatosplenomegaly.

Blood or plasma may appear:

Milky or lactescent.

29. Pancreatitis in LPL Deficiency

Recurrent acute pancreatitis is one of the most important complications.

Therefore:

CHILD/YOUNG PERSON + EXTREME TRIGLYCERIDES + RECURRENT PANCREATITIS → THINK FAMILIAL CHYLOMICRONAEMIA.

30. Treatment of LPL Deficiency

Management differs from ordinary hypertriglyceridaemia.

The cornerstone is a:

Very-low-fat diet

to reduce formation of dietary chylomicrons.

Alcohol and other triglyceride-raising factors should be avoided.

Because the primary defect is severe impairment of the LPL pathway, traditional triglyceride-lowering drugs such as fibrates may have:

Limited effectiveness in true complete LPL deficiency.

This is an important distinction from ordinary familial hypertriglyceridaemia.

31. Familial Combined Hyperlipidaemia

Familial combined hyperlipidaemia – FCHL is a common inherited dyslipidaemia associated with increased production of:

ApoB-containing lipoproteins.

Affected family members may show different lipid patterns.

32. Lipid Pattern in Familial Combined Hyperlipidaemia

Patients may have:

High LDL cholesterol.

High triglycerides.

or

Both elevated cholesterol and triglycerides.

The lipid phenotype may vary over time and between relatives.

Therefore the original description of:

Elevated cholesterol and triglycerides

is broadly correct, but not every patient necessarily has both raised simultaneously.

33. ApoB in Familial Combined Hyperlipidaemia

A characteristic feature is often:

Elevated apolipoprotein B – ApoB.

This reflects an increased number of:

Atherogenic lipoprotein particles.

This contributes to the disorder’s strong association with premature cardiovascular disease.

34. Atherosclerosis in Familial Combined Hyperlipidaemia

The major clinical concern is:

Premature atherosclerosis.

Patients have increased risk of:

Coronary artery disease

and other atherosclerotic cardiovascular disease.

Unlike classic FH, tendon xanthomas are generally:

Not characteristic.

35. Familial Combined Hyperlipidaemia and Metabolic Factors

FCHL often coexists with features such as:

Obesity.

Insulin resistance.

Hypertension.

These factors may worsen the lipid phenotype and cardiovascular risk.

36. Treatment of Familial Combined Hyperlipidaemia

Treatment focuses on reducing overall cardiovascular risk.

This includes:

Diet and weight management.

Exercise.

Smoking cessation.

Management of diabetes and hypertension.

LDL-lowering therapy, often with statins.

Additional triglyceride-lowering therapy may be considered according to the lipid pattern.

37. Familial Hypercholesterolaemia – Note Form

Inheritance:

Usually autosomal dominant.

Typical defect:

LDL receptor pathway.

↓

Reduced LDL clearance.

↓

Markedly increased LDL cholesterol.

Heterozygous FH:

Commoner than old 1:500 estimate; roughly 1:200–300 in many populations.

Premature coronary disease.

Tendon xanthomas.

Xanthelasma may occur.

Premature corneal arcus may occur.

Homozygous FH:

Very rare.

Extremely high LDL from childhood.

Childhood xanthomas.

Very premature coronary and aortic atherosclerosis.

MI can occur in childhood/adolescence.

Treatment:

Lifestyle measures.

High-intensity statin.

Ezetimibe.

PCSK9-targeted therapy when needed.

Specialist therapy/apheresis in severe HoFH.

38. Familial Hypertriglyceridaemia – Note Form

Main abnormality:

Raised triglycerides, usually VLDL predominant.

Possible features when severe:

Turbid plasma.

Eruptive xanthomas.

Pancreatitis.

Lipemia retinalis.

Hepatomegaly ± splenomegaly.

Treatment:

Diet.

Weight loss where appropriate.

Avoid excess alcohol.

Control diabetes.

Fibrates for suitable patients.

39. Lipoprotein Lipase Deficiency – Note Form

Inheritance:

Autosomal recessive.

Defect:

LPL pathway failure.

↓

Failure to clear chylomicron triglyceride normally.

↓

Extreme hypertriglyceridaemia.

Clinical features:

Childhood onset.

Milky plasma.

Eruptive xanthomas.

Lipemia retinalis.

Hepatosplenomegaly.

Recurrent pancreatitis.

Treatment:

Very-low-fat diet is central.

Traditional fibrates may be relatively ineffective in complete LPL deficiency.

40. Familial Combined Hyperlipidaemia – Note Form

Lipid abnormality:

↑ LDL cholesterol.

or

↑ Triglycerides.

or

↑ Both.

Typical additional clue:

↑ ApoB.

Major complication:

Premature atherosclerotic cardiovascular disease.

Tendon xanthomas:

Generally absent, helping distinguish it from classical FH.

41. Important Corrections to the Original Notes

The traditional prevalence:

“Heterozygous FH ≈ 1 in 500”

is now considered too low.

Modern estimates are closer to:

ABOUT 1 IN 200–300, depending on the population.

The original fixed cholesterol range:

9–15 mmol/L

can occur in HeFH, but diagnosis is not based on a single universal cholesterol range. The key abnormality is:

MARKEDLY ELEVATED LDL FROM A YOUNG AGE.

The older statement of:

“six- to eightfold increased IHD risk”

captures the substantial risk but should not be treated as a fixed value for every patient.

The clinically important message is:

UNTREATED FH → MARKEDLY INCREASED PREMATURE ASCVD RISK.

For severe hypertriglyceridaemia, the classic retinal manifestation is:

LIPEMIA RETINALIS

rather than retinal vein thrombosis as the defining association.

LPL deficiency should be distinguished from ordinary familial hypertriglyceridaemia.

In true LPL deficiency:

CHYLOMICRONS ACCUMULATE MASSIVELY

and treatment is centred on:

STRICT DIETARY FAT RESTRICTION.

Familial combined hyperlipidaemia may cause raised cholesterol, triglycerides, or both—not necessarily both in every affected person.

Key Clinical Pattern

For rapid recall:

FAMILIAL HYPERCHOLESTEROLAEMIA → VERY HIGH LDL + TENDON XANTHOMAS + PREMATURE CORONARY DISEASE.

HOMOZYGOUS FH → CHILDHOOD XANTHOMAS + VERY EARLY ATHEROSCLEROSIS/MI.

FAMILIAL HYPERTRIGLYCERIDAEMIA → HIGH TG + PANCREATITIS RISK.

LPL DEFICIENCY → AR + CHYLOMICRONS + EXTREME TG + RECURRENT PANCREATITIS.

FAMILIAL COMBINED HYPERLIPIDAEMIA → ↑ LDL AND/OR ↑ TG + ↑ ApoB + PREMATURE ATHEROSCLEROSIS.

The easiest final distinction is:

TENDON XANTHOMA → THINK FAMILIAL HYPERCHOLESTEROLAEMIA.

ERUPTIVE XANTHOMA + PANCREATITIS → THINK SEVERE HYPERTRIGLYCERIDAEMIA.

Medicine – Causes of Secondary Hyperlipidaemia

Secondary hyperlipidaemia means elevated blood lipids caused by an underlying disease, medication, lifestyle factor, or physiological state rather than by a primary inherited lipid disorder.

The pattern may be predominantly:

Raised cholesterol, especially LDL cholesterol,

or

Raised triglycerides,

although mixed abnormalities are common.

⸻

1. Mainly Raised Cholesterol

Conditions that predominantly increase cholesterol include:

Hypothyroidism.

Cholestasis.

Nephrotic syndrome.

Renal transplantation.

⸻

2. Hypothyroidism

Hypothyroidism commonly causes:

Raised total cholesterol

and

Raised LDL cholesterol.

The major mechanism is reduced hepatic expression and activity of:

LDL receptors.

This decreases clearance of LDL particles from the circulation.

Therefore:

HYPOTHYROIDISM → ↓ LDL CLEARANCE → ↑ LDL CHOLESTEROL.

⸻

3. Lipid Pattern in Hypothyroidism

The typical pattern is:

↑ LDL cholesterol.

↑ Total cholesterol.

Triglycerides may also rise, especially in more severe disease, so the abnormality is not always purely hypercholesterolaemic.

⸻

4. Clinical Importance

When otherwise unexplained hypercholesterolaemia is found, particularly with symptoms such as:

Fatigue.

Weight gain.

Cold intolerance.

Constipation.

it is reasonable to consider:

Hypothyroidism.

Treating the thyroid disorder may improve the lipid profile.

⸻

5. Cholestasis

Cholestasis means impaired formation or flow of bile.

It can produce marked:

Hypercholesterolaemia.

This may occur in:

Extrahepatic biliary obstruction

or

Intrahepatic cholestatic disease.

⸻

6. Mechanism in Cholestasis

An important abnormal lipoprotein can appear in cholestasis:

Lipoprotein X – Lp-X.

This cholesterol-rich particle contributes to the marked increase in measured serum cholesterol.

Therefore:

CHOLESTASIS → Lp-X ACCUMULATION → MARKED HYPERCHOLESTEROLAEMIA.

⸻

7. Clinical Clues to Cholestasis

Associated features may include:

Jaundice.

Pruritus.

Dark urine.

Pale stools.

Raised alkaline phosphatase.

Thus a high cholesterol concentration in a jaundiced patient may reflect:

Cholestasis rather than a primary lipid disorder.

⸻

8. Nephrotic Syndrome

The original notes correctly include:

Nephrotic syndrome.

The classic nephrotic picture consists of:

Heavy proteinuria.

Hypoalbuminaemia.

Oedema.

Hyperlipidaemia.

⸻

9. Mechanism of Hyperlipidaemia in Nephrotic Syndrome

Loss of albumin in urine lowers plasma oncotic pressure and stimulates increased hepatic synthesis of proteins and lipoproteins.

At the same time, lipid clearance may also be impaired.

This produces increases in:

LDL.

VLDL.

Total cholesterol.

Triglycerides.

Therefore nephrotic syndrome may produce:

Mixed hyperlipidaemia, not only isolated hypercholesterolaemia.

⸻

10. Typical Lipid Pattern in Nephrotic Syndrome

The most striking finding is often:

Markedly raised cholesterol.

However, triglycerides can also rise.

Therefore:

NEPHROTIC SYNDROME → ↑ CHOLESTEROL ± ↑ TRIGLYCERIDES.

⸻

11. Renal Transplantation

Hyperlipidaemia is common after:

Renal transplantation.

The lipid pattern may include:

Raised total cholesterol.

Raised LDL.

Raised triglycerides.

So, again, it may be:

Mixed rather than purely cholesterol-predominant.

⸻

12. Why Renal Transplantation Causes Dyslipidaemia

Several factors contribute, including:

Immunosuppressive medications.

Persistent CKD.

Weight gain.

Diabetes.

Hypertension.

Reduced physical activity.

⸻

13. Immunosuppressive Drugs

Important transplant medications that can worsen lipid profiles include:

Corticosteroids.

Ciclosporin.

Sirolimus and related mTOR inhibitors.

Tacrolimus tends to have a less pronounced lipid effect than ciclosporin, although metabolic complications can still occur.

⸻

14. Mainly Raised Triglycerides

Conditions that predominantly increase triglycerides include:

Obesity.

Insulin resistance.

Diabetes mellitus.

Chronic alcohol excess.

Several other secondary causes can also produce hypertriglyceridaemia.

⸻

15. Obesity

Obesity, particularly:

Visceral or central obesity,

is strongly associated with:

Insulin resistance.

Insulin resistance increases release of free fatty acids from adipose tissue and promotes hepatic synthesis of:

Triglycerides and VLDL.

Therefore:

OBESITY → INSULIN RESISTANCE → ↑ VLDL → ↑ TRIGLYCERIDES.

⸻

16. Insulin Resistance

Insulin normally suppresses:

Lipolysis in adipose tissue.

With insulin resistance, this suppression becomes less effective.

More free fatty acids reach the:

Liver.

The liver uses these fatty acids to synthesise:

Triglycerides.

These are exported mainly in:

VLDL particles.

⸻

17. Metabolic Syndrome Pattern

The typical dyslipidaemia of insulin resistance includes:

Raised triglycerides.

Low HDL cholesterol.

Small dense LDL particles.

This pattern is often seen in:

Metabolic syndrome.

⸻

18. Diabetes Mellitus

Poorly controlled diabetes, especially with marked insulin deficiency or resistance, can cause:

Hypertriglyceridaemia.

The mechanism includes:

Increased lipolysis.

Increased hepatic VLDL production.

Reduced triglyceride-rich lipoprotein clearance.

⸻

19. Severe Hypertriglyceridaemia in Diabetes

Very poorly controlled diabetes can occasionally produce:

Severe hypertriglyceridaemia.

When triglycerides become extremely high, there is an increased risk of:

Acute pancreatitis.

Therefore severe triglyceride elevation should prompt assessment for:

Uncontrolled diabetes.

⸻

20. Chronic Alcohol Excess

The original notes correctly include:

Chronic alcohol excess.

Alcohol increases hepatic:

Fatty acid synthesis

and

Triglyceride production.

It can therefore increase:

VLDL secretion.

⸻

21. Alcohol and Triglycerides

The typical pattern is:

Raised triglycerides.

The rise may be particularly marked when alcohol excess occurs together with:

Obesity.

Diabetes.

High carbohydrate intake.

⸻

22. Pancreatitis Risk

Alcohol excess can therefore contribute to pancreatitis in two different ways:

Direct alcohol toxicity

and

Severe hypertriglyceridaemia.

This becomes particularly relevant when triglycerides are very high.

⸻

23. Other Important Causes of Secondary Hypertriglyceridaemia

Important additional causes include:

Pregnancy.

Chronic kidney disease.

Certain medications.

Excessive refined carbohydrate intake.

Some endocrine disorders.

⸻

24. Pregnancy

During pregnancy, especially later pregnancy, triglycerides physiologically increase because of changes in:

Oestrogen.

Insulin resistance.

Hepatic lipoprotein production.

Usually this is physiological, but in susceptible individuals triglycerides can become markedly elevated.

⸻

25. Chronic Kidney Disease

CKD commonly causes abnormalities in triglyceride-rich lipoprotein metabolism.

The typical pattern may include:

Raised triglycerides.

Reduced HDL.

LDL concentration may be normal or variably elevated.

⸻

26. Medications Causing Hypertriglyceridaemia

Drugs that may increase triglycerides include:

Corticosteroids.

Oestrogens.

Retinoids.

Some antipsychotics.

Certain HIV therapies.

Some beta-blockers.

Thiazide diuretics, particularly at higher doses.

The degree of effect varies considerably between patients and agents.

⸻

27. Mixed Secondary Hyperlipidaemia

Many secondary causes do not fit neatly into a single “cholesterol” or “triglyceride” category.

Examples include:

Nephrotic syndrome.

Renal transplantation.

Diabetes.

CKD.

These can produce:

Mixed dyslipidaemia.

Therefore the original classification is useful for memorisation but should not be considered absolute.

⸻

28. Mainly Raised Cholesterol – Note Form

Hypothyroidism:

↓ LDL receptor activity.

↓

↓ LDL clearance.

↓

↑ LDL cholesterol.

⸻

Cholestasis:

Lipoprotein X accumulation.

↓

Marked hypercholesterolaemia.

⸻

Nephrotic syndrome:

↑ Hepatic lipoprotein synthesis + impaired clearance.

↓

↑ Cholesterol ± ↑ triglycerides.

⸻

Renal transplantation:

Immunosuppressive drugs + metabolic factors.

↓

Often mixed dyslipidaemia.

⸻

29. Mainly Raised Triglycerides – Note Form

Obesity:

Insulin resistance.

↓

↑ Free fatty acids.

↓

↑ Hepatic VLDL.

↓

↑ Triglycerides.

⸻

Diabetes mellitus:

Insulin resistance or deficiency.

↓

↑ VLDL production + impaired clearance.

↓

↑ Triglycerides.

⸻

Chronic alcohol excess:

↑ Hepatic triglyceride synthesis.

↓

↑ VLDL.

↓

↑ Triglycerides.

⸻

30. Important Corrections and Clarifications

The original division into:

“mainly raised cholesterol”

and

“mainly raised triglycerides”

is useful for revision, but many secondary causes produce overlapping abnormalities.

⸻

Nephrotic syndrome often produces:

BOTH HIGH CHOLESTEROL AND HIGH TRIGLYCERIDES, although cholesterol may be especially prominent.

⸻

Renal transplantation can also produce:

MIXED DYSLIPIDAEMIA, rather than isolated hypercholesterolaemia.

⸻

Diabetes particularly raises triglycerides when metabolic control is poor, and it often produces the characteristic insulin-resistant pattern of:

↑ TG + ↓ HDL + SMALL DENSE LDL.

⸻

Key Clinical Pattern

For rapid recall:

HYPOTHYROIDISM → ↑ LDL CHOLESTEROL.

CHOLESTASIS → ↑ CHOLESTEROL, OFTEN VIA LIPOPROTEIN X.

NEPHROTIC SYNDROME → ↑ CHOLESTEROL ± ↑ TRIGLYCERIDES.

RENAL TRANSPLANT → MIXED DYSLIPIDAEMIA, OFTEN DRUG-RELATED.

OBESITY / INSULIN RESISTANCE / DIABETES → ↑ TRIGLYCERIDES.

ALCOHOL EXCESS → ↑ TRIGLYCERIDES.

A useful final distinction is:

CHOLESTEROL-PREDOMINANT → THINK HYPOTHYROIDISM, CHOLESTASIS, NEPHROTIC SYNDROME.

TRIGLYCERIDE-PREDOMINANT → THINK INSULIN RESISTANCE, DIABETES, OBESITY, ALCOHOL.

Surgery - Secondary Survey

Objectives of the Secondary Survey

The secondary survey begins after immediate life-threatening injuries have been identified and treated.

Its purpose is to obtain a definitive history, perform a thorough examination, assimilate relevant investigations, and formulate an appropriate management plan.

The patient should be examined systematically from head to toe, including both the front and back of the body.

A thorough assessment includes examination of all relevant orifices where indicated, traditionally summarized by the phrase “fingers and tubes in every orifice.”

A detailed history of the incident should be obtained, including collateral information from witnesses, paramedics, or accompanying persons when available.

A complete medical history should also be obtained.

All directed investigations should be reviewed and incorporated into the overall clinical assessment.

The secondary survey should conclude with the formulation of a definitive management plan.

Investigations

Any investigations relevant to the patient’s injuries and clinical condition should be performed.

At the very least, a trauma imaging series should be obtained or considered as appropriate, together with basic blood investigations and an electrocardiogram (ECG).

Further investigations should be directed by the mechanism of injury, examination findings, and the patient’s clinical condition.

History

A paramedic handover should be obtained to establish the mechanism of injury, events at the scene, pre-hospital findings, and any treatment already given.

A collateral history should be obtained from witnesses or accompanying persons whenever possible.

The patient’s own history should be obtained whenever their clinical condition allows.

An AMPLE medical history should also be obtained.

A – Allergies: Any known drug, food, or other relevant allergies should be identified.

M – Medications: Current medications should be documented.

P – Past Medical History: Relevant previous medical conditions, operations, and comorbidities should be established.

L – Last Meal: The timing of the patient’s last meal or oral intake should be determined.

E – Events Leading to the Situation: The events and circumstances leading to the injury or current situation should be clarified.

Deterioration During the Secondary Survey

If there is any change or deterioration in the patient’s clinical condition during the secondary survey, assessment should immediately return to the ABCDE approach.

Any newly identified life-threatening problem should be evaluated and treated as necessary.

The secondary survey should only be resumed once the patient has been sufficiently stabilized.

Surgery - Pelvis

Clinical Findings Suggesting Pelvic Injury

Obvious deformity or an open injury may indicate significant pelvic trauma.

Localised pelvic pain or limb paraesthesia may suggest associated bony or neurological injury.

Signs of retroperitoneal haemorrhage include bruising of the scrotum, buttocks, or along the line of the inguinal ligament, known as Fox’s sign.

Signs of urethral injury include blood at the urethral meatus, a high-riding prostate, and an inability to void urine.

Rectal examination may reveal blood or palpable bony fragments.

Reduced anal tone may indicate associated neurological or lumbosacral injury.

Abnormal pelvic stability on clinical assessment may also suggest disruption of the pelvic ring.

Types of Pelvic Injury

External rotation of the hemipelvis occurs with disruption of the pubic symphysis and is typically associated with anteroposterior compression.

This injury pattern may be caused by a direct anteroposterior compression force.

It may also result from a direct posterior blow to the iliac spines.

Forced external rotation of the lower limb can also produce this pattern of pelvic injury.

Internal rotation of the hemipelvis is associated with compression fractures of the pubic rami and usually results from lateral compression.

This pattern is typically caused by a lateral impact producing medial compression of the pelvis.

Vertical shear injury involves fracture-dislocation of the hemipelvis with superior and posterior displacement.

It is caused by a vertical loading force that fractures the pubic rami and disrupts the sacroiliac joint, resulting in displacement of the affected hemipelvis.

Pelvic Springing

Pelvic springing is a clinical test used to assess the stability and integrity of the pelvic ring.

It involves gentle compression of the iliac wings.

The aim is to identify pelvic instability that may suggest a fracture before imaging is obtained.

Main Concern in Pelvic Fracture

The major concern in pelvic fracture is uncontrolled haemorrhage into the pelvic cavity.

The pelvis can accommodate several litres of blood, so significant haemorrhage may occur before it becomes externally apparent.

Interim Management of Unstable Pelvic Fractures

A sheet may be placed beneath the buttocks and wrapped anteriorly around the pelvis, with the ends secured to provide a basic temporary splint.

Anterior external fixation may be used by inserting two pins into the anterior border of the ilium on each side and connecting them with a rigid external frame.

Posterior external fixation may involve pin insertion along the line between the anterior superior iliac spine and posterior superior iliac spine, with the pins connected using a reduction clamp.

External fixation should be performed by an experienced orthopaedic surgeon because of the risk of iatrogenic neurovascular injury.

Surgery - Musculoskeletal

Musculoskeletal Injuries Contributing to Shock

Several musculoskeletal injuries can result in significant blood loss and contribute to haemorrhagic shock. These include arterial bleeding, pelvic fractures, large vessel puncture, limb amputation, and long bone fractures. Long bone fractures can conceal substantial amounts of blood loss. A humeral fracture may be associated with approximately 0.5–1.5 litres of blood loss, a tibial fracture with approximately 0.5–1.5 litres, and a femoral fracture with approximately 1.0–2.5 litres.

Musculoskeletal Assessment in the Secondary Survey

The primary survey and ABCs should always be addressed first. Once the patient is stable, the musculoskeletal system can be assessed systematically during the secondary survey. This includes taking a focused history and examining the patient using the principles of look, feel, and move.

History

The history should include the position of the patient when first found or on arrival, any obvious or suspected trauma, and the mechanism of injury. In road traffic accidents, important details include seatbelt use, airbag deployment, whether the patient was able to mobilise after the accident, and the direction of impact. It is also useful to determine whether the patient was found close to or away from the accident site.

An AMPLE history should be taken, including allergies, medications, past medical history, last meal, and events surrounding the injury. Previous joint or limb pathology should also be identified. Osteoporosis and osteopenia are especially important because they increase susceptibility to fractures following relatively minor trauma.

Inspection

The patient should be appropriately exposed and both sides of the body compared. Look for open fractures, which may involve exposed bone but are not always immediately obvious. Other important features include swelling, deformity, bruising, wounds, and changes in the colour of the limb distal to the injury.

Palpation

Both sides should be compared while assessing the temperature of the distal limb, the presence of crepitus, joint effusions, haemarthroses, and capillary refill time. In a conscious patient, pain and tenderness should also be assessed. Neurological integrity should be checked by assessing fine touch sensation, motor function, and sweating of the skin, or hidrosis.

Movement

Range of active movement should be assessed in a conscious patient. Passive movement may be considered in an unconscious patient where appropriate. However, an obvious or suspected fracture should not be manipulated before X-ray imaging, as this does not add significantly to the diagnosis and may worsen the injury. Joint dislocations should generally be reduced as soon as clinically appropriate. Weight-bearing may be assessed as tolerated when relevant.

Investigations

Plain X-rays are the standard initial investigation for uncomplicated musculoskeletal trauma. Imaging should be selected according to the suspected site and type of injury.

Rule of Twos

The rule of twos is a useful principle when assessing fractures radiologically. Two joints should be considered, meaning the joint above and the joint below the injury should be assessed where appropriate. Two views, usually an anteroposterior and lateral view, should be obtained to assess displacement and angulation accurately. If doubt remains, the opposite side may occasionally be imaged for comparison, although this is rarely required.

Surgery - Glossary of Surgical Terminology

Abduct

Abduct means movement of an extremity away from the midline of the body.

Adduct

Adduct means movement of an extremity towards the midline of the body.

Adeno-

The prefix adeno- refers to glands or glandular tissue.

Afferent

Afferent means travelling or conducting towards a central structure.

Anastomosis

An anastomosis is a surgically created connection between two tubular structures, such as two segments of bowel or two blood vessels.

Angio-

The prefix angio- refers to blood vessels.

Anomalous

Anomalous means deviating from what is considered normal or expected.

Aseptic

Aseptic refers to the complete absence of disease-causing microorganisms or to measures used to prevent microbial contamination.

Atelectasis

Atelectasis refers to collapse of the alveoli, resulting in partial or complete loss of lung volume in the affected area.

Atresia

Atresia is the congenital absence or abnormal narrowing of a normal opening or lumen. The adjective is atretic.

Biopsy

A biopsy is a sample of tissue obtained from the body and sent for histopathological examination to establish a diagnosis.

Cachexia

Cachexia is generalized wasting and loss of body mass associated with chronic disease or malignancy. A patient affected by this condition may be described as cachectic.

Calculus

A calculus is a stone or solid concretion formed within the body, such as a renal or biliary calculus.

Calor

Calor is one of the classic signs of inflammation and refers to increased warmth in the affected area.

Caseation

Caseation is the breakdown of diseased tissue into a soft, cheese-like material. The adjective is caseous.

Caudal

Caudal means relating to or directed towards the lower part of the body.

Cephal-

The prefix cephal- refers to the head.

Cicatrix

A cicatrix is a scar formed after healing of damaged tissue.

Colic

Colic is pain that occurs in waves, usually due to contraction or obstruction of a hollow or tubular organ.

Curettage

Curettage is the scraping of the internal surface of an organ or body cavity using a spoon-shaped surgical instrument known as a curette.

Cyst

A cyst is an abnormal sac lined by epithelium and containing fluid or semi-solid material.

Diaphoresis

Diaphoresis refers to excessive or profuse sweating.

Diverticulum

A diverticulum is a small sac or pouch projecting from the wall of a hollow organ. A true diverticulum contains all the layers of the parent organ, as in Meckel’s diverticulum. A pseudodiverticulum contains only some of the normal wall layers, as commonly seen in diverticular disease of the colon.

Dolor

Dolor is one of the classic signs of inflammation and refers to pain.

Dysphagia

Dysphagia means difficulty swallowing. It should be distinguished from odynophagia, which means painful swallowing.

Ecchymosis

Ecchymosis refers to bruising caused by bleeding into the tissues beneath the skin.

-ectomy

The suffix -ectomy means surgical removal of an organ or structure. For example, parotidectomy is surgical removal of the parotid gland.

Epistaxis

Epistaxis means bleeding from the nose, commonly referred to as a nosebleed.

Excision Biopsy

An excision biopsy is a biopsy in which the entire lesion or tumour is removed for histopathological examination.

Fistula

A fistula is an abnormal epithelialized communication between two epithelial surfaces, organs, or body cavities.

Frequency

Urinary frequency refers to abnormally frequent urination.

Functio Laesa

Functio laesa is one of the classic signs of inflammation and refers to loss or impairment of function.

Haemangioma

A haemangioma is a benign tumour or proliferation of blood vessels.

Haematemesis

Haematemesis means vomiting of blood, usually indicating bleeding from the upper gastrointestinal tract.

Haematoma

A haematoma is a localized collection of blood within tissues that forms a swelling or mass. It may resolve spontaneously or may become secondarily infected.

Haematuria

Haematuria refers to the presence of blood in the urine.

Haemoptysis

Haemoptysis refers to coughing up blood originating from the respiratory tract.

Haemothorax

A haemothorax is the accumulation of blood within the pleural space.

Hesitancy

Urinary hesitancy refers to difficulty in initiating the flow of urine.

Icterus

Icterus is another term for jaundice, characterized by yellow discoloration of the skin, sclerae, and mucous membranes due to elevated bilirubin levels.

Incisional Biopsy

An incisional biopsy is a biopsy in which only part of a lesion or tumour is removed for histopathological examination rather than removing the entire lesion.

Induration

Induration refers to abnormal hardening of a tissue or organ, often caused by inflammation, infiltration, or fibrosis.

Intussusception

Intussusception occurs when one segment of the bowel telescopes into an adjacent segment of bowel, potentially causing intestinal obstruction and impairment of blood supply.

Laparoscopy

Laparoscopy is the visualization of the peritoneal cavity using a laparoscope inserted through small incisions. It uses optical technology to allow inspection and surgical procedures within the abdomen.

Laparotomy

A laparotomy is the surgical opening of the abdominal cavity through an incision.

Lumen

The lumen is the cavity or internal space within a tubular organ, such as the bowel or a blood vessel. The adjective is luminal.

Melaena

Melaena refers to black, tarry stools caused by digested blood, most commonly due to bleeding from the upper gastrointestinal tract.

Nocturia

Nocturia refers to abnormal urination during the night, typically requiring the patient to wake from sleep to pass urine.

Obstipation

Obstipation is the complete inability to pass either stool or flatus and may indicate severe intestinal obstruction.

Odynophagia

Odynophagia means painful swallowing.

Orchid-

The prefix orchid- refers to the testis or testicles.

-orrhaphy

The suffix -orrhaphy refers to surgical repair by suturing. For example, herniorrhaphy is the surgical repair of a hernia.

-ostomy

The suffix -ostomy refers to the surgical creation of an opening or stoma. For example, a colostomy is a surgically created opening of the colon onto the abdominal wall.

-otomy

The suffix -otomy refers to a surgical incision into an organ or structure. For example, a laparotomy involves making an incision into the abdominal cavity.

-pexy

The suffix -pexy refers to the surgical fixation of an organ or structure. For example, orchidopexy is surgical fixation of the testis.

Phlegmon

A phlegmon is a solid, swollen, inflamed mass of tissue. In pancreatitis, the term may be used to describe an inflammatory pancreatic mass.

Pneumaturia

Pneumaturia refers to the passage of gas or air in the urine. It may occur in conditions such as an enterovesical fistula.

Pneumothorax

A pneumothorax is the presence of air within the pleural space, which may cause partial or complete collapse of the affected lung.

Pus

Pus is a thick fluid produced during inflammation, particularly bacterial infection, and consists of inflammatory cells, microorganisms, and tissue debris. The correct adjective is purulent.

Rubor

Rubor is one of the classic signs of inflammation and refers to redness of the affected area.

Sinus

A sinus is an abnormal, blind-ending epithelialized tract that connects a deeper focus of disease to an epithelial surface.

Stenosis

Stenosis means abnormal narrowing of a lumen, passage, or opening.

Suppuration

Suppuration refers to the formation or discharge of pus.

Transection

Transection means transverse or complete division across a structure.

Volar

Volar refers to the surface of the palm of the hand or, in some anatomical contexts, the corresponding flexor surface.

Surgery - Surgical Abbreviations

General Symbols and Terms

# — Fracture.

1ry, 2ry, etc. — Primary, secondary, etc.

a/aa — Artery/arteries.

n/nn — Nerve/nerves.

v/vv — Vein/veins.

AA

AA — Alcoholics Anonymous.

ABG

ABG — Arterial blood gas.

ABPI

ABPI — Ankle-brachial pressure index.

Ab/AdPL/B

Ab/AdPL/B — Abductor/adductor pollicis longus/brevis.

Abx

Abx — Antibiotics.

AC

AC — Air conduction.

ACTH

ACTH — Adrenocorticotrophic hormone.

AF

AF — Atrial fibrillation.

AK[A]

AK[A] — Above knee [amputation].

AIDS

AIDS — Acquired immunodeficiency syndrome.

ALP

ALP — Alkaline phosphatase.

Amp

Amp — Ampicillin.

AOE

AOE — Acute otitis externa.

AOM

AOM — Acute otitis media.

AP

AP — Antero-posterior X-ray.

aPTT

aPTT — Activated partial thromboplastin time.

ARDS

ARDS — Adult respiratory distress syndrome.

ASA

ASA — Amino-salicylic acid (aspirin).

ASD

ASD — Atrial septal defect.

ASIS

ASIS — Anterior superior iliac spine.

AST

AST — Aspartate aminotransferase.

AXR

AXR — Abdominal X-ray.

BC

BC — Bone conduction.

bd

bd — Bis die, meaning twice daily.

BE

BE — Below elbow.

BK[A]

BK[A] — Below knee [amputation].

BLS

BLS — Basic Life Support.

BP

BP — Blood pressure.

CA

CA — Carcinoma.

CABG

CABG — Coronary artery bypass graft, sometimes pronounced “cabbage”.

CCF

CCF — Congestive cardiac failure.

Cef

Cef — Cefuroxime.

chrm

chrm — Chromosome.

CIS

CIS — Carcinoma in situ.

CMV

CMV — Cytomegalovirus.

C/O

C/O — Complains of.

COPD

COPD — Chronic obstructive pulmonary disease.

CRP

CRP — C-reactive protein, an inflammatory marker.

CRT

CRT — Capillary refill time.

CSOM

CSOM — Chronic suppurative otitis media.

CT

CT — Computed tomography.

CVA

CVA — Cerebrovascular accident. The term “stroke” is generally preferred.

CVP

CVP — Central venous pressure.

CXR

CXR — Chest X-ray.

D5W

D5W — Dextrose 5% in water.

DHx

DHx — Drug history.

DIC

DIC — Disseminated intravascular coagulation.

DIPJ

DIPJ — Distal interphalangeal joint.

DM

DM — Diabetes mellitus.

DRE

DRE — Digital rectal examination.

DT

DT — Delirium tremens.

DVT

DVT — Deep vein thrombosis.

Dx

Dx — Diagnosis.

ECG

ECG — Electrocardiogram.

Echo

Echo — Echocardiogram.

ENT

ENT — Ear, nose and throat.

EPB/L

EPB/L — Extensor pollicis brevis/longus.

ESR

ESR — Erythrocyte sedimentation rate.

ETOH

ETOH — Alcohol.

EUA

EUA — Examination under anaesthesia.

Ex-Fix

Ex-Fix — External fixation.

FBC

FBC — Full blood count.

FDP

FDP — Fibrin degradation products.

FDP/S

FDP/S — Flexor digitorum profundus/superficialis.

FESS

FESS — Functional endoscopic sinus surgery.

FFP

FFP — Fresh frozen plasma.

FNA[C]

FNA[C] — Fine needle aspirate [cytology].

FOOSH

FOOSH — Fall on the outstretched hand.

FTSG

FTSG — Full thickness skin graft.

GA

GA — General anaesthetic.

GCS

GCS — Glasgow Coma Scale.

Gent

Gent — Gentamicin.

GP

GP — General Practitioner.

G&S

G&S — Group and save.

GTN

GTN — Glyceryl trinitrate.

GXM

GXM — Group and cross match.

HIV

HIV — Human immunodeficiency virus.

HPV

HPV — Human papilloma virus.

HTN

HTN — Hypertension.

HZO

HZO — Herpes zoster ophthalmicus.

ICP

ICP — Intracranial pressure.

I&D

I&D — Incision and drainage, commonly used for abscesses.

IHD

IHD — Ischaemic heart disease.

IMN

IMN — Intramedullary nailing.

IOP

IOP — Intra-ocular pressure.

ITU

ITU — Intensive Therapy Unit.

IVC

IVC — Inferior vena cava.

IVDU

IVDU — Intravenous drug user.

IVF

IVF — Intravenous fluids.

IVP/U

IVP/U — Intravenous pyelogram/urogram.

JVP

JVP — Jugular venous pressure.

KUB

KUB — Kidneys, ureters and bladder plain film.

LA

LA — Local anaesthetic.

lat

lat — Lateral X-ray.

LFT

LFT — Liver function test.

LUQ

LUQ — Left upper quadrant.

MAX FAX

MAX FAX — Maxillo-facial surgery.

MC

MC — Metacarpal.

M/C/S

M/C/S — Microscopy, culture and sensitivity.

Metro

Metro — Metronidazole.

MI

MI — Myocardial infarction.

MOF

MOF — Multiorgan failure.

MSU

MSU — Midstream urine.

MUA

MUA — Manipulation under anaesthetic.

N/A

N/A — Not applicable.

NAD

NAD — Nil abnormality detected.

NBM

NBM — Nil by mouth.

NGT

NGT — Nasogastric tube.

NOF

NOF — Neck of femur.

N/S

N/S — Normal saline.

NSAIDs

NSAIDs — Non-steroidal anti-inflammatory drugs.

OA

OA — Osteoarthritis.

OCP

OCP — Oral contraceptive pill.

od

od — Omni die, meaning once daily.

qds

qds — Quater die sumendus, meaning to be taken four times daily.

OGD

OGD — Oesophagogastroduodenoscopy.

OPG

OPG — Orthopantomogram.

ORIF

ORIF — Open reduction and internal fixation.

OT

OT — Operating Theatre/Occupational Therapist.

PAN

PAN — Polyarteritis nodosum.

PCA

PCA — Patient-controlled analgesia.

PCWP

PCWP — Pulmonary capillary wedge pressure.

PDA

PDA — Patent ductus arteriosus.

PE

PE — Pulmonary embolism.

PEEP

PEEP — Positive end-expiratory pressure.

PERLA

PERLA — Pupils equal and reactive to light and accommodation.

PICU

PICU — Paediatric intensive therapy unit.

PIPJ

PIPJ — Proximal interphalangeal joint.

PMHx

PMHx — Past medical history.

PO

PO — Per os, meaning orally.

POP

POP — Plaster of Paris.

PR

PR — Per rectum, meaning rectally.

PRN

PRN — Pro re nata, meaning as needed.

PSIS

PSIS — Posterior superior iliac spine.

PT

PT — Prothrombin time.

PTCA

PTCA — Percutaneous transluminal coronary angioplasty.

PUD

PUD — Peptic ulcer disease.

PV

PV — Per vaginum, meaning vaginally.

qxh

qxh — Every x hours. For example, q3h means every 3 hours.

RAPD

RAPD — Relative afferent pupillary defect.

RBS

RBS — Random blood sugar.

r/o

r/o — Rule out.

RTA

RTA — Road traffic accident.

RUQ

RUQ — Right upper quadrant.

Rx

Rx — Treatment.

SCC

SCC — Squamous cell carcinoma.

SIRS

SIRS — Systemic inflammatory response syndrome.

SLE

SLE — Systemic lupus erythematosus.

SNHL

SNHL — Sensorineural hearing loss.

SOB

SOB — Shortness of breath.

SSG

SSG — Split skin graft.

stat

stat — Immediately.

STD

STD — Sexually transmitted disease.

SVC

SVC — Superior vena cava.

Sx

Sx — Surgery.

SXR

SXR — Skull X-ray.

TB

TB — Tuberculosis.

tds

tds — Ter die sumendus, meaning to be taken three times daily.

TIA

TIA — Transient ischaemic attack.

TM

TM — Tympanic membrane.

TMJ

TMJ — Temporomandibular joint.

TOE

TOE — Transoesophageal echocardiogram.

TPN

TPN — Total parenteral nutrition.

TRAM

TRAM — Transverse rectus abdominis muscle.

TTE

TTE — Transthoracic echocardiogram.

UC

UC — Ulcerative colitis.

U&Es

U&Es — Urea and electrolytes, including creatinine.

U/O

U/O — Urine output.

URTI

URTI — Upper respiratory tract infection.

USS

USS — Ultrasound scan.

UTI

UTI — Urinary tract infection.

Vanc

Vanc — Vancomycin.

VE

VE — Vaginal examination.

VSD

VSD — Ventricular septal defect.

VUJ

VUJ — Vesico-ureteric junction.

WBC/WCC

WBC/WCC — White blood cells/white cell count.

Surgery-

Surgical Signs, Tests, Laws, Syndromes and Eponyms

Allen’s Test

Allen’s test is used to assess the circulation of the hand and the patency of the radial and ulnar arteries. The patient is asked to drain the hand of blood by forming a fist while the examiner compresses both the radial and ulnar arteries. The patient then opens the hand, which should appear blanched. One artery is released and the examiner observes for palmar flushing, indicating arterial patency. The procedure is then repeated for the other artery.

Argyll Robertson Pupil

Argyll Robertson pupil is a condition in which the pupil constricts or dilates appropriately during accommodation but does not respond to light. In other words, the accommodation reflex is preserved while the pupillary light reflex is absent. A useful mnemonic is ARP, PRA, which translates to Accommodation Reflex Present, Pupillary Response Absent.

Barton’s Fracture

Barton’s fracture is a fracture-dislocation of the distal radius and may sometimes be mistaken for a Colles’ fracture. The fracture line extends across the volar lip of the radius and into the wrist joint. The hand and the associated fragment of distal radius undergo proximal and volar displacement.

Battle’s Sign

Battle’s sign is ecchymosis over the mastoid or post-auricular region and is associated with a basal skull fracture. It is an important clinical sign indicating possible fracture of the base of the skull.

Beck’s Triad

Beck’s triad is classically seen in cardiac tamponade. It consists of jugular venous distension, muffled heart sounds, and decreased blood pressure or hypotension. These findings result from impaired cardiac filling due to pressure from fluid within the pericardial sac.

Bell’s Palsy

Bell’s palsy is an acute lower motor neurone facial nerve palsy of unknown aetiology. It produces weakness or paralysis of the muscles on one side of the face and is generally regarded as a diagnosis of exclusion.

Chvostek’s Sign

Chvostek’s sign is seen in hypocalcaemia. It is elicited by tapping over the facial nerve, which causes twitching or contraction of the facial muscles due to increased neuromuscular excitability.

Colles’ Fracture

A Colles’ fracture is a fracture of the distal approximately 2 cm of the radius with dorsal displacement of the distal fragment. This produces the characteristic dinner-fork deformity of the wrist.

Compartment Syndrome

Compartment syndrome is a condition in which pressure increases within a confined anatomical compartment. The rising pressure adversely affects circulation and threatens the function and viability of the muscles, nerves, and other tissues within that compartment.

Cushing’s Triad

Cushing’s triad is seen in raised intracranial pressure. It consists of increased blood pressure, bradycardia, and irregular respirations. These findings may indicate severe intracranial hypertension.

De Quervain’s Tenosynovitis

De Quervain’s tenosynovitis is inflammation of the extensor pollicis brevis (EPB) and abductor pollicis longus (AbPL) tendons, usually secondary to overuse. It causes pain around the radial side of the wrist and may be demonstrated clinically using Finkelstein’s test.

Finkelstein’s Test

Finkelstein’s test is used to assess for De Quervain’s tenosynovitis. The thumb is clenched within the fist and the wrist is moved in a way that stretches the extensor pollicis brevis and abductor pollicis longus tendons. Reproduction of pain over the radial aspect of the wrist supports the diagnosis.

Frey’s Syndrome

Frey’s syndrome is characterized by warmth, flushing, and sweating in the malar or parotid region of the face during eating, or even when thinking or talking about food. It is also known as gustatory sweating. It may follow damage in the parotid region caused by trauma, mumps, purulent infection, or parotidectomy. After the initial damage, autonomic fibres that previously supplied the salivary glands may regenerate incorrectly and connect with sweat glands. As a result, a stimulus that normally causes salivation instead causes sweating and flushing. Flushing has been described as more prevalent in females and sweating as more prevalent in males. Gustatory tears, also known as crocodile tears, may sometimes occur.

Galeazzi Fracture

A Galeazzi fracture is a fracture of the radial shaft associated with dislocation of the distal radioulnar joint. This disrupts the normal forearm axis. It is sometimes referred to as a reverse Monteggia fracture.

Gradenigo’s Syndrome

Gradenigo’s syndrome is seen as a complication of suppurative otitis media. It consists of signs of acute suppurative otitis media, ipsilateral abducens nerve palsy, and pain in the distribution of the ipsilateral trigeminal nerve.

Hitselberger’s Sign

Hitselberger’s sign is an abnormal sensory change involving the posterior external auditory canal, classically associated with acoustic neuroma. It may occur together with ipsilateral hearing loss.

Horner’s Syndrome

Horner’s syndrome results from disruption of the ipsilateral sympathetic nerve supply to the eye and face. It is characterized by ipsilateral ptosis, miosis, anhidrosis, and apparent enophthalmos. A classic cause is a Pancoast tumour, which is a tumour arising from the upper part or apex of the lung.

Monteggia Fracture

A Monteggia fracture consists of dislocation of the radial head associated with a fracture of the proximal third of the ulna.

Osler–Rendu–Weber Syndrome

Osler–Rendu–Weber syndrome, also known as hereditary haemorrhagic telangiectasia, is a familial disorder characterized by telangiectasia affecting mucosal surfaces. These vascular lesions may be present in several areas, but a common presentation is recurrent epistaxis.

Pendred’s Syndrome

Pendred’s syndrome is an autosomal recessive disorder characterized by congenital sensorineural hearing loss and thyroid enlargement or goitre.

Pierre Robin Sequence

Pierre Robin sequence is characterized by a hypoplastic or small mandible, cleft palate, and glossoptosis. Glossoptosis refers to posterior or downward displacement of the tongue and may contribute to upper airway obstruction or obstructive sleep apnoea. External, middle, and inner ear problems may also occur.

Raccoon Eyes

Raccoon eyes are seen in basal skull fractures and consist of bilateral periorbital ecchymosis. The appearance is also known as panda eyes.

Refsum’s Disease

Refsum’s disease is characterized by retinitis pigmentosa, cerebellar ataxia, peripheral neuropathy, and sensorineural hearing loss. It is an inherited metabolic disorder with prominent neurological, ophthalmological, and auditory manifestations.

Ramsay Hunt Syndrome

Ramsay Hunt syndrome is a facial nerve palsy caused by herpes zoster infection involving the facial nerve. It presents with a lower motor neurone facial nerve palsy together with painful vesicular or haemorrhagic blistering involving the ipsilateral ear or tympanic membrane. It is also known as herpes zoster oticus.

Smith’s Fracture

A Smith’s fracture is a fracture of the distal radius that usually occurs when a patient lands on a flexed wrist. The distal radial fragment is displaced anteriorly or volarly. It is often referred to as a reverse Colles’ fracture.

Superior Vena Cava Syndrome

Superior vena cava syndrome is caused by obstruction of the superior vena cava, for example by a tumour or thrombosis. It produces venous congestion and engorgement of the face, neck, and upper chest veins in the distribution of the superior vena cava.

Thoracic Outlet Syndrome

Thoracic outlet syndrome occurs when structures passing through the thoracic outlet are compressed. Possible causes include a cervical rib. Depending on the structures affected, the patient may develop neurological or vascular symptoms involving the upper limb.

Thornwaldt’s Cyst

A Thornwaldt’s cyst is a benign cystic swelling of the nasopharynx and is uncommon, particularly in adults. It arises from the pharyngeal bursa and is located in the superoposterior nasopharynx. A sufficiently large cyst may contribute to obstruction in this region.

Treacher Collins Syndrome

Treacher Collins syndrome is an autosomal dominant craniofacial disorder characterized by hypoplasia of the maxilla and mandible. Patients may also have microtia, meaning small or underdeveloped ears, together with abnormalities of the external, middle, or inner ear and associated hearing problems.

Trousseau’s Sign

Trousseau’s sign is seen in hypocalcaemia. It is demonstrated by producing temporary blood-flow occlusion with a blood pressure cuff, which causes carpopedal spasm due to increased neuromuscular excitability.

Waardenburg Syndrome

Waardenburg syndrome is an inherited disorder characterized by abnormalities of pigmentation and hearing. Features include telecanthus, pigment abnormalities such as a white forelock and heterochromia iridis, and sensorineural hearing loss. Telecanthus refers to an increased distance between the inner corners of the eyes.

Ophthalmology – Congenital Orbital Tumors

Basics

Description

Congenital orbital tumors and developmental masses are lesions present at birth or arising during early childhood.

The most important entities in this group include:

• Dermoid cyst
• Epidermoid cyst
• Orbital teratoma

Other congenital orbital masses include:

• Lymphatic malformations
• Venous/venolymphatic malformations
• Congenital cystic eye
• Colobomatous cyst
• Encephalocele

Orbital Dermoid and Epidermoid Cysts

These are benign developmental cysts caused by sequestration of ectoderm during embryologic fusion.

They are among the:

Most common orbital masses in children

Typical locations are along bony sutures, especially the:

Frontozymgomatic suture in the superotemporal orbit

Less commonly they occur:

• Superonasally
• Deep within the orbit
• Within bone
• Within orbital soft tissue without obvious suture attachment

Dermoid vs Epidermoid Cyst

Dermoid Cyst

Lined by keratinizing stratified squamous epithelium and contains dermal appendages such as:

• Hair follicles
• Sebaceous glands
• Sweat glands

Contents may include:

• Keratin
• Sebum
• Hair

Epidermoid Cyst

Also lined by stratified squamous epithelium but:

Lacks dermal appendages

It predominantly contains:

• Desquamated keratin

Epidemiology

Dermoid and epidermoid cysts are commonly diagnosed in:

• Infancy
• Early childhood

but may present at any age.

There is no strong sex predilection.

They represent a substantial proportion of excised pediatric orbital lesions.

Orbital Teratoma

Orbital teratoma is a:

Very rare congenital germ-cell tumor

It usually presents:

• At birth
• Shortly after birth

Most are:

• Unilateral
• Mature
• Histologically benign

They can become enormous and produce marked orbital expansion.

Pathophysiology

Dermoid/Epidermoid Cysts

They arise when ectoderm becomes trapped during embryonic fusion along:

• Bony sutures
• Lines of closure

Types may be described anatomically as:

• Juxtasutural
• Sutural
• Soft-tissue/deep orbital

Slow accumulation of keratinous or sebaceous material causes progressive enlargement.

Dermoid Cyst Rupture

Spontaneous or traumatic rupture releases lipid and keratin into surrounding tissues and can cause:

Marked granulomatous inflammation

resulting in:

• Pain
• Redness
• Swelling
• Orbital inflammation

This may mimic infection.

Orbital Teratoma Pathophysiology

Teratomas arise from pluripotent germ cells and contain tissues derived from all three germ layers:

• Ectoderm
• Mesoderm
• Endoderm

They may contain:

• Fat
• Bone
• Cartilage
• Neural tissue
• Epithelium
• Cystic structures

Clinical Presentation

Dermoid / Epidermoid Cyst

Typically presents as:

• Painless
• Slowly enlarging
• Subcutaneous orbital or periocular mass

The classic lesion is:

Superotemporal near the frontozygomatic suture

On palpation it is often:

• Smooth
• Firm or fluctuant
• Nontender
• Partially mobile relative to skin

Associated Findings

Most superficial dermoids do not cause:

• Visual loss
• Elevated IOP
• Significant motility disturbance

Large or deep lesions can cause:

• Globe displacement
• Proptosis
• Diplopia
• Astigmatism
• Amblyopia

Astigmatism and Amblyopia

A lesion compressing the globe may produce:

• Corneal astigmatism
• Anisometropia

which can lead to:

Amblyopia in young children

Therefore refraction should be checked in pediatric patients.

Deep Orbital Dermoid

Deep lesions may present later with:

• Progressive proptosis
• Globe displacement
• Diplopia
• Motility restriction

They are less likely to be visible externally.

Orbital Teratoma – Clinical Presentation

The classic presentation is:

Massive unilateral proptosis present at birth

Features may include:

• Markedly enlarged orbit
• Tense eyelids
• Severe globe displacement
• Exposure keratopathy
• Conjunctival keratinization
• Corneal ulceration
• Vascular congestion

Vision may be severely compromised from:

• Optic nerve stretching/compression
• Exposure damage
• Amblyopia

History

Dermoid / Epidermoid

Usually:

• Long-standing
• Slowly progressive
• Asymptomatic

Sudden pain and swelling suggest:

• Rupture
• Hemorrhage
• Secondary inflammation

Trauma may precipitate rupture but is not the underlying cause.

Orbital Teratoma

History usually reveals:

• Proptosis at birth
• Rapid enlargement during early infancy
• Severe unilateral orbital expansion

Examination

Assess:

• Visual acuity
• Pupils
• Refraction
• Ocular alignment
• Motility
• Degree and direction of globe displacement
• Proptosis
• Exposure keratopathy
• Fundus

In young children, specifically evaluate for:

Amblyopia

Imaging – Dermoid and Epidermoid Cysts

Imaging is particularly useful for:

• Deep lesions
• Fixed lesions
• Atypical location
• Suspected intracranial extension
• Surgical planning

CT

CT is particularly useful for demonstrating:

• Relationship to orbital bone
• Suture location
• Bony remodeling
• Intraosseous extension

A dermoid is often:

• Round or ovoid
• Well circumscribed

Its density varies depending on:

• Fat
• Sebaceous material
• Keratin

A fat-fluid level may occasionally be present.

MRI

MRI provides superior soft-tissue assessment.

Signal characteristics are variable depending on cyst contents.

MRI is especially useful for:

• Deep lesions
• Intracranial extension
• Complex orbital anatomy

Epidermoid on MRI

Epidermoid cysts can show:

Restricted diffusion on diffusion-weighted imaging

which may help distinguish them from other cystic lesions.

Imaging – Orbital Teratoma

Both CT and MRI usually demonstrate a:

Large heterogeneous, multiloculated orbital mass

containing mixtures of:

• Solid tissue
• Cystic components
• Fat
• Calcification
• Bone

CT in Teratoma

CT is particularly good for identifying:

• Calcification
• Ossification
• Orbital expansion
• Bony remodeling

The combination of:

Fat + fluid/cystic tissue + calcification

strongly suggests teratoma.

MRI in Teratoma

MRI better defines:

• Soft-tissue components
• Optic nerve relationship
• Globe compression
• Intracranial extension

Pathology

Dermoid Cyst

Histology shows:

• Keratinizing stratified squamous epithelium
• Hair follicles
• Sebaceous glands
• Sweat glands

Inflammatory giant-cell reaction may occur after rupture.

Epidermoid Cyst

Histology shows:

• Keratinizing squamous epithelial lining
• Keratinaceous contents
• No dermal appendages

Teratoma

A mature teratoma contains differentiated tissue from all three germ layers.

Grossly it may be:

• Solid
• Cystic
• Multiloculated
• Partially calcified or ossified

Most congenital orbital teratomas are mature and benign.

Differential Diagnosis

The differential for an orbital mass in an infant or child includes:

• Infantile hemangioma
• Venous malformation
• Lymphatic malformation
• Rhabdomyosarcoma
• Optic pathway glioma
• Neuroblastoma metastasis
• Retinoblastoma with orbital extension
• Leukemia/chloroma
• Langerhans cell histiocytosis
• Orbital cellulitis
• Abscess
• Lacrimal lesions
• Mucocele
• Encephalocele
• Colobomatous cyst
• Congenital cystic eye

Infantile Hemangioma

Previously often called capillary hemangioma.

Usually develops during the first weeks of life rather than being fully developed at birth.

May cause:

• Eyelid swelling
• Proptosis
• Globe displacement
• Astigmatism
• Amblyopia

It is distinguished from venous/lymphatic malformations by its characteristic proliferative and involutional course.

Lymphatic Malformation

Previously called lymphangioma.

It is a congenital vascular malformation that may involve:

• Eyelid
• Conjunctiva
• Orbit

It often enlarges gradually but may suddenly expand from:

• Intralesional hemorrhage
• Upper respiratory infection

MRI frequently demonstrates:

• Multiloculated cystic spaces
• Fluid-fluid levels after hemorrhage

Rhabdomyosarcoma

The most important malignant pediatric orbital differential.

Typical features:

• Rapidly progressive proptosis
• Eyelid swelling
• Globe displacement
• First decade of life

Unlike a dermoid, it generally enlarges over:

Days to weeks

rather than years.

Optic Pathway Glioma

Usually presents with:

• Slowly progressive visual loss
• Optic atrophy or disc swelling
• Proptosis with intraorbital optic nerve involvement

It is strongly associated with:

NF1

MRI demonstrates:

• Fusiform enlargement of the optic nerve

Modern management is generally observation or systemic therapy when progressive, not routine surgical excision.

Neuroblastoma

Orbital metastatic neuroblastoma may present with:

• Proptosis
• Periorbital ecchymosis
• Eyelid swelling

Bilateral orbital disease is particularly suggestive.

Congenital Cystic Eye

A rare developmental anomaly caused by failure of normal globe formation.

The orbit contains:

• Cystic primitive neuroectodermal/ocular tissue

with no normally developed eye.

Encephalocele

A congenital skull defect may permit herniation of:

• Meninges
• Brain tissue

into or near the orbit.

Imaging before surgery is essential because of intracranial communication.

Colobomatous Cyst

Usually occurs with:

• Microphthalmia
• Inferior ocular coloboma

A cyst extends through the embryonic fissure defect and may occupy part of the orbit.

Treatment – Dermoid/Epidermoid Cyst

Small, asymptomatic lesions may sometimes be observed.

Surgical excision is generally favored when there is:

• Progressive enlargement
• Cosmetic deformity
• Pain
• Recurrent inflammation
• Globe displacement
• Astigmatism
• Amblyopia risk
• Exposure to repeated trauma
• Diagnostic uncertainty

Surgical Excision

The goal is:

Complete removal of the cyst with the capsule intact

because rupture can cause:

• Intense inflammation
• Foreign-body granuloma
• Incomplete removal
• Recurrence

If rupture occurs intraoperatively, copious irrigation and removal of cyst contents are important.

Deep Dermoid

Deep orbital dermoids require careful preoperative imaging because they may:

• Extend through sutures
• Cause bony remodeling
• Have intracranial extension

Surgical approach depends on location and extent.

Treatment – Orbital Teratoma

The main treatment is:

Early surgical excision

Goals are to:

• Preserve the globe when possible
• Protect visual potential
• Reduce exposure complications
• Preserve orbital and facial growth
• Achieve good cosmesis

Globe Preservation

Modern surgery emphasizes globe-sparing removal whenever technically possible.

Because most congenital orbital teratomas are benign:

Radical surgery should be avoided when adequate complete excision can preserve the eye and orbit.

Exenteration

Orbital exenteration is now:

Rarely required

and reserved for extraordinary cases in which the mass cannot otherwise be safely controlled or the orbital structures are irreversibly compromised.

Postoperative Care

Monitor for:

• Residual or recurrent lesion
• Visual impairment
• Amblyopia
• Strabismus
• Orbital asymmetry
• Exposure disease
• Need for reconstructive surgery

Follow-Up – Dermoid/Epidermoid

If observation is selected, monitor for:

• Growth
• New pain
• Inflammation
• Globe displacement
• Visual effects

After complete excision, recurrence is uncommon.

Follow-Up – Teratoma

Follow-up should assess:

• Recurrence
• Orbital development
• Globe position
• Vision
• Amblyopia
• Cosmetic development

Repeat imaging is appropriate when:

• Excision was incomplete
• Pathology is atypical
• Recurrence is suspected

Prognosis

Dermoid/Epidermoid Cysts

Prognosis is:

Excellent

Most children maintain normal vision if:

• Astigmatism is detected
• Amblyopia is treated
• Complicated rupture is avoided

Complete excision is usually curative.

Orbital Teratoma

Systemic prognosis is generally excellent because most congenital orbital teratomas are:

Mature and benign

Visual prognosis is more variable.

It depends on:

• Duration and severity of proptosis
• Optic nerve compression
• Exposure keratopathy
• Degree of globe distortion
• Amblyopia

Even when the globe can be preserved, useful vision may be limited.

Complications

Dermoid/Epidermoid

Potential complications include:

• Cyst rupture
• Granulomatous inflammation
• Pain
• Globe displacement
• Astigmatism
• Amblyopia
• Recurrence after incomplete excision

Orbital Teratoma

Potential complications include:

• Massive proptosis
• Exposure keratopathy
• Corneal ulceration
• Optic nerve injury
• Permanent visual loss
• Amblyopia
• Orbital/facial asymmetry
• Rare recurrence

Malignant transformation of a mature congenital orbital teratoma is exceedingly uncommon.

Ophthalmology Pearls

• Dermoid cyst is one of the most common orbital masses of childhood.
• The classic dermoid is a painless superotemporal mass at the frontozygomatic suture.
• Dermoid cysts contain skin appendages; epidermoid cysts do not.
• Sudden painful enlargement of a previously quiet dermoid suggests rupture with granulomatous inflammation.
• Large orbital dermoids can induce astigmatism and amblyopia, so refraction matters in children.
• CT is particularly useful for bone and calcification; MRI is better for soft tissue and intracranial extension.
• Epidermoid cysts characteristically may show restricted diffusion on MRI.
• Orbital teratoma classically causes massive unilateral proptosis at birth.
• A teratoma containing fat, cystic tissue, and calcification on imaging is highly characteristic.
• Mature orbital teratomas contain tissue from all three germ layers: ectoderm, mesoderm, and endoderm.
• Complete dermoid excision should ideally preserve the capsule because rupture increases inflammation and recurrence risk.
• Modern teratoma surgery aims for globe preservation, with exenteration reserved for exceptional cases.
• In a child with rapidly progressive proptosis, always exclude rhabdomyosarcoma.
• Use modern terminology: infantile hemangioma rather than capillary hemangioma, and lymphatic malformation rather than lymphangioma.

Medicine – Vitamin Deficiencies

Vitamins are essential organic compounds required in relatively small amounts for normal metabolism, neurological function, blood formation, vision, bone health, coagulation and tissue maintenance. Deficiency may occur because of poor dietary intake, malabsorption, chronic illness, alcohol misuse, increased physiological requirements or medications that interfere with vitamin metabolism.

A useful first distinction is between fat-soluble vitamins A, D, E and K and the water-soluble B-group vitamins and vitamin C. Fat malabsorption therefore particularly predisposes to deficiencies of:

A, D, E and K.

1. Vitamin A Deficiency

Vitamin A is important for:

Vision.

Epithelial integrity.

Immune function.

Cell differentiation.

The retinal form of vitamin A participates in formation of visual pigments required for vision, particularly in:

Low-light conditions.

Causes of Vitamin A Deficiency

The original notes correctly include:

Protein-energy malnutrition.

Other important causes include:

Severe dietary deficiency.

Fat malabsorption.

Chronic cholestatic liver disease.

Pancreatic insufficiency.

Because vitamin A is fat-soluble, disorders that impair fat absorption can reduce its absorption.

Night Blindness

One of the earliest characteristic manifestations is:

Night blindness – nyctalopia.

The patient has difficulty seeing when moving from a bright environment into:

Dim light.

Therefore:

VITAMIN A DEFICIENCY → NIGHT BLINDNESS.

Xerophthalmia

More severe deficiency produces dryness of the:

Conjunctiva and cornea.

This is part of:

Xerophthalmia.

Characteristic ocular abnormalities can include:

Conjunctival xerosis.

Bitot spots.

Corneal xerosis.

Keratomalacia

Severe vitamin A deficiency may cause:

Keratomalacia.

This involves softening and destruction of the cornea and can result in:

Permanent blindness.

Therefore:

VITAMIN A → NIGHT BLINDNESS → XEROPHTHALMIA → KERATOMALACIA.

2. Vitamin B1 – Thiamine Deficiency

Thiamine – vitamin B1 is essential for carbohydrate metabolism and normal neurological and cardiac function.

Thiamine deficiency is particularly important because severe neurological deficiency can become:

A medical emergency.

Causes of Thiamine Deficiency

The original notes include:

Alcohol misuse

and

Dietary restriction.

Other causes include:

Severe malnutrition.

Prolonged vomiting.

Malabsorption.

Bariatric surgery.

Increased metabolic requirements.

Chronic alcohol misuse is particularly important because it can combine:

Poor intake + impaired absorption + reduced storage/utilisation.

3. Dry Beriberi

Neurological thiamine deficiency produces:

Dry beriberi.

Typical manifestations include:

Peripheral neuropathy.

Muscle weakness.

Reduced reflexes.

Sensory abnormalities.

Therefore:

DRY BERIBERI = MAINLY NEUROLOGICAL.

4. Wet Beriberi

Cardiovascular thiamine deficiency produces:

Wet beriberi.

This may cause:

Peripheral vasodilatation.

Tachycardia.

Oedema.

High-output cardiac failure.

Therefore:

WET BERIBERI = MAINLY CARDIOVASCULAR.

5. Wernicke Encephalopathy

Severe thiamine deficiency can cause:

Wernicke encephalopathy.

The classic triad is:

Confusion.

Ataxia.

Ocular abnormalities, such as ophthalmoplegia or nystagmus.

However, the complete triad is often absent.

Therefore thiamine should be given promptly when Wernicke encephalopathy is suspected.

6. Korsakoff Syndrome

Untreated or prolonged thiamine deficiency may progress to:

Korsakoff syndrome.

Typical features include:

Severe anterograde amnesia.

Memory impairment.

Confabulation.

The older combined term:

Wernicke–Korsakoff syndrome

describes the relationship between the acute encephalopathic and chronic amnestic manifestations.

7. Vitamin B2 – Riboflavin Deficiency

Riboflavin – vitamin B2 is required for flavin-containing coenzymes involved in:

Cellular energy metabolism.

Deficiency commonly occurs in association with:

General malnutrition.

Causes of Riboflavin Deficiency

The original notes include:

Protein-energy malnutrition.

Other situations associated with deficiency include:

Poor dietary intake.

Malabsorption.

Chronic alcohol misuse.

Deficiency often occurs together with other vitamin deficiencies rather than in isolation.

Clinical Features

Characteristic manifestations include:

Angular cheilitis/stomatitis.

Glossitis.

The tongue may become:

Red and inflamed.

Other mucocutaneous changes can also occur.

Therefore:

B2 DEFICIENCY → GLOSSITIS + ANGULAR STOMATITIS/CHEILITIS.

8. Niacin – Vitamin B3 Deficiency

Niacin – vitamin B3 is required for formation of:

NAD and NADP.

These coenzymes participate in numerous oxidation-reduction reactions and energy-producing pathways.

Causes of Niacin Deficiency

The original notes include:

Alcohol misuse.

Isoniazid.

Carcinoid syndrome.

Severe dietary deficiency or malabsorption can also cause niacin deficiency.

Carcinoid Syndrome and Niacin

Tryptophan can normally be used for:

Niacin synthesis.

In carcinoid syndrome, large amounts of tryptophan may be diverted toward:

Serotonin synthesis.

This reduces substrate available for niacin production and can contribute to:

Pellagra.

9. Pellagra

Niacin deficiency causes:

Pellagra.

The classic manifestations are remembered as the:

Four Ds.

Dermatitis.

Diarrhoea.

Dementia.

Death.

Pellagra Dermatitis

The dermatitis is characteristically:

Photosensitive.

It tends to affect sun-exposed skin.

A characteristic distribution around the neck is traditionally called:

Casal’s necklace.

Therefore:

NIACIN DEFICIENCY → PELLAGRA → 4 Ds.

10. Vitamin B6 – Pyridoxine Deficiency

Pyridoxine – vitamin B6 is important in:

Amino-acid metabolism.

Neurotransmitter synthesis.

Haem synthesis.

Causes of Vitamin B6 Deficiency

The original notes correctly include:

Isoniazid

and

Hydralazine.

Isoniazid is particularly important because it interferes with pyridoxine metabolism.

Clinical Features

Vitamin B6 deficiency may cause:

Peripheral neuropathy.

Glossitis.

Cheilosis.

Dermatitis.

It can also impair haem synthesis and produce:

Sideroblastic anaemia.

In severe deficiency, neurological manifestations such as seizures can occur.

Isoniazid and Pyridoxine

A classic examination association is:

ISONIAZID → B6 DEFICIENCY → PERIPHERAL NEUROPATHY.

Pyridoxine supplementation is therefore given to patients at increased risk of isoniazid-associated neuropathy.

11. Vitamin B12 – Cobalamin Deficiency

Vitamin B12 – cobalamin is essential for:

DNA synthesis.

Normal red-cell production.

Neurological function.

Myelin maintenance.

The image uses the term cyanocobalamin, which is one pharmaceutical form of vitamin B12; cobalamin is the broader physiological term.

Causes of Vitamin B12 Deficiency

Important causes include:

Pernicious anaemia.

Autoimmune gastritis.

Gastrectomy.

Terminal ileal disease or resection.

Crohn disease affecting the terminal ileum.

Severe dietary deficiency, especially prolonged strict vegan intake without supplementation.

Malabsorption.

Some medications, such as prolonged metformin use, can also contribute.

12. Pernicious Anaemia

Pernicious anaemia results from autoimmune loss of:

Intrinsic factor

and gastric parietal-cell dysfunction.

Intrinsic factor is required for B12 absorption in the:

Terminal ileum.

Therefore:

LOSS OF INTRINSIC FACTOR → B12 MALABSORPTION → B12 DEFICIENCY.

13. Haematological Features of B12 Deficiency

B12 deficiency impairs DNA synthesis and can produce:

Megaloblastic macrocytic anaemia.

Blood film may show:

Macro-ovalocytes.

Hypersegmented neutrophils.

14. Neurological Features of B12 Deficiency

Unlike isolated folate deficiency, B12 deficiency can cause significant:

Neurological disease.

Features include:

Peripheral neuropathy.

Loss of vibration sensation.

Loss of proprioception.

Sensory ataxia.

Spastic weakness.

Subacute Combined Degeneration

Severe B12 deficiency may cause:

Subacute combined degeneration of the spinal cord.

This predominantly affects:

Posterior columns

and

Corticospinal tracts.

Therefore:

B12 DEFICIENCY → MACROCYTIC ANAEMIA + NEUROLOGICAL DEFICITS.

15. Vitamin C Deficiency

Vitamin C – ascorbic acid is essential for normal:

Collagen synthesis.

It is also important for wound healing and enhances:

Non-haem iron absorption.

Humans cannot synthesise sufficient vitamin C and therefore depend on:

Dietary intake.

Cause of Vitamin C Deficiency

The major cause is:

Inadequate dietary intake.

Risk increases with:

Severe dietary restriction.

Malnutrition.

Alcohol misuse with poor diet.

Extreme food selectivity.

16. Scurvy

Vitamin C deficiency causes:

Scurvy.

Defective collagen formation leads to:

Fragile blood vessels and connective tissue abnormalities.

Clinical Features of Scurvy

Features include:

Swollen or bleeding gums.

Easy bruising.

Petechiae or perifollicular haemorrhage.

Poor wound healing.

Joint or bone pain.

Fatigue.

Therefore:

VITAMIN C DEFICIENCY → SCURVY → BLEEDING GUMS + BRUISING + POOR WOUND HEALING.

17. Vitamin D Deficiency

Vitamin D is essential for normal:

Calcium and phosphate homeostasis

and

Bone mineralisation.

Its active form is:

1,25-dihydroxyvitamin D – calcitriol.

Causes of Vitamin D Deficiency

The original notes include:

Renal failure

and

Dietary deficiency.

Important additional causes include:

Reduced sunlight exposure.

Fat malabsorption.

Cholestatic disease.

Severe liver disease.

18. Vitamin D and Chronic Kidney Disease

Advanced CKD does not simply cause a nutritional vitamin D deficiency.

The kidney normally converts 25-hydroxyvitamin D into:

Active calcitriol

through:

1α-hydroxylase.

In CKD:

↓ Functional renal mass

↓

↓ Calcitriol production

↓

↓ Intestinal calcium absorption

↓

Secondary hyperparathyroidism

↓

CKD-mineral and bone disorder.

Therefore the original term “renal failure → vitamin D deficiency” is directionally useful but physiologically simplified.

19. Rickets

Vitamin D deficiency in children causes:

Rickets.

Because growing bones are affected, manifestations can include:

Bowed legs.

Widened wrists.

Rachitic rosary.

Growth impairment.

20. Osteomalacia

In adults, defective mineralisation causes:

Osteomalacia.

Patients may develop:

Diffuse bone pain.

Proximal muscle weakness.

Fragility or insufficiency fractures.

Therefore:

VITAMIN D DEFICIENCY → RICKETS IN CHILDREN, OSTEOMALACIA IN ADULTS.

21. Vitamin E Deficiency

Vitamin E – tocopherol is an important:

Lipid-soluble antioxidant.

It protects cell membranes against:

Oxidative damage.

Causes of Vitamin E Deficiency

The original notes correctly include:

Fat malabsorption

and

Abetalipoproteinaemia.

Because vitamin E is fat-soluble, deficiency occurs particularly in disorders involving:

Chronic fat malabsorption.

22. Abetalipoproteinaemia

Abetalipoproteinaemia impairs the formation and transport of:

ApoB-containing lipoproteins.

This results in severe malabsorption and transport abnormalities involving:

Fat-soluble vitamins, particularly vitamin E.

23. Neurological Features of Vitamin E Deficiency

Vitamin E deficiency can cause:

Peripheral neuropathy.

Ataxia.

Loss of vibration and proprioception.

Hyporeflexia.

Spinocerebellar dysfunction.

Therefore the original description:

Spinocerebellar degeneration

captures an important manifestation but does not represent the full neurological picture.

Other Features

Vitamin E deficiency may also cause:

Haemolytic anaemia, particularly in susceptible patients.

A useful memory association is:

VITAMIN E DEFICIENCY → NEUROLOGICAL DYSFUNCTION + HAEMOLYSIS.

24. Vitamin K Deficiency

Vitamin K is required for normal activation of several:

Coagulation factors.

It acts as a cofactor for:

γ-carboxylation

of vitamin K-dependent proteins.

Vitamin K-Dependent Factors

The major vitamin K-dependent coagulation factors are:

II, VII, IX and X.

Vitamin K is also required for:

Protein C

and

Protein S.

25. Causes of Vitamin K Deficiency

The original notes correctly include:

Biliary obstruction

and

Antibiotic therapy.

Other causes include:

Fat malabsorption.

Poor dietary intake in susceptible patients.

Neonatal deficiency.

26. Biliary Obstruction and Vitamin K

Vitamin K is:

Fat-soluble.

Normal absorption therefore requires adequate:

Bile salts.

In biliary obstruction, reduced bile delivery to the intestine impairs fat absorption.

Therefore:

BILIARY OBSTRUCTION → ↓ VITAMIN K ABSORPTION → BLEEDING TENDENCY.

27. Antibiotics and Vitamin K

Prolonged broad-spectrum antibiotic treatment can reduce:

Intestinal bacterial contribution to vitamin K availability.

This becomes more important when combined with:

Poor nutrition

or

Malabsorption.

28. Consequences of Vitamin K Deficiency

Vitamin K deficiency impairs coagulation and produces:

Bleeding tendency.

Possible manifestations include:

Easy bruising.

Mucosal bleeding.

GI bleeding.

Haemorrhage in severe cases.

Laboratory testing commonly shows early prolongation of:

Prothrombin time – PT/INR, because factor VII has a relatively short half-life.

29. Fat-Soluble Vitamins – Note Form

Vitamin A:

Deficiency → night blindness, xerophthalmia, Bitot spots, keratomalacia.

Vitamin D:

Deficiency/impaired activation → defective bone mineralisation.

Children → rickets.

Adults → osteomalacia.

Vitamin E:

Deficiency → neuropathy, ataxia, spinocerebellar dysfunction ± haemolysis.

Vitamin K:

Deficiency → impaired coagulation and bleeding.

30. Water-Soluble Vitamins – Note Form

B1 – Thiamine:

Dry beriberi → neuropathy.

Wet beriberi → high-output heart failure.

Wernicke encephalopathy → confusion + ataxia + ocular abnormalities.

Korsakoff syndrome → severe memory impairment/confabulation.

B2 – Riboflavin:

Glossitis.

Angular stomatitis/cheilitis.

B3 – Niacin:

Pellagra.

Dermatitis + diarrhoea + dementia + death.

B6 – Pyridoxine:

Peripheral neuropathy.

Glossitis.

Sideroblastic anaemia.

Classic drug association → isoniazid.

B12 – Cobalamin:

Megaloblastic anaemia.

Peripheral neuropathy.

Subacute combined degeneration.

Vitamin C:

Scurvy.

Bleeding gums.

Bruising.

Poor wound healing.

31. Important Corrections and Additions

The original vitamin A section is correct, but an important additional classic finding is:

BITOT SPOTS.

For vitamin B1, Wernicke encephalopathy and Korsakoff syndrome are related but clinically distinct:

WERNICKE = ACUTE NEUROLOGICAL EMERGENCY.

KORSAKOFF = CHRONIC AMNESTIC SYNDROME.

For niacin, remember the classic:

4 Ds → DERMATITIS + DIARRHOEA + DEMENTIA + DEATH.

For vitamin B6, an important additional manifestation is:

SIDEROBLASTIC ANAEMIA.

For vitamin B12, the key distinction from folate deficiency is:

B12 DEFICIENCY CAN CAUSE NEUROLOGICAL DAMAGE.

For vitamin D, advanced CKD particularly causes:

IMPAIRED ACTIVATION OF VITAMIN D TO CALCITRIOL, contributing to secondary hyperparathyroidism and CKD-mineral and bone disorder.

For vitamin E, the consequences extend beyond spinocerebellar degeneration and include:

PERIPHERAL NEUROPATHY + ATAXIA ± HAEMOLYTIC ANAEMIA.

For vitamin K, the key mechanism is failure of normal activation of:

FACTORS II, VII, IX AND X + PROTEINS C AND S.

Key Clinical Pattern

For rapid recall:

A → EYES → NIGHT BLINDNESS / XEROPHTHALMIA.

B1 → BRAIN + NERVES + HEART → WERNICKE / BERIBERI.

B2 → MOUTH → GLOSSITIS + ANGULAR CHEILITIS.

B3 → 4 Ds → DERMATITIS + DIARRHOEA + DEMENTIA + DEATH.

B6 → ISONIAZID → NEUROPATHY ± SIDEROBLASTIC ANAEMIA.

B12 → BLOOD + SPINAL CORD → MEGALOBLASTIC ANAEMIA + SUBACUTE COMBINED DEGENERATION.

C → COLLAGEN → SCURVY + BLEEDING GUMS + POOR WOUND HEALING.

D → BONE → RICKETS / OSTEOMALACIA.

E → NEUROLOGICAL DYSFUNCTION ± HAEMOLYSIS.

K → KOAGULATION → BLEEDING.

And remember the fat-soluble vitamins simply as:

A – D – E – K.