Emergency And Acute Medicine – Anaphylaxis


Clinical Overview
Anaphylaxis is an acute, life-threatening systemic hypersensitivity reaction that develops rapidly after exposure to an antigen in a sensitized individual. It represents a form of distributive shock caused by widespread mediator release, leading to vasodilation, increased vascular permeability, smooth-muscle contraction, and excessive glandular secretion. These physiologic changes result in reduced systemic vascular resistance, decreased venous return and cardiac output, and intravascular volume depletion. Anaphylaxis accounts for hundreds of deaths annually in the United States and thousands of emergency department visits each month.


Underlying Causes
IgE-mediated reactions are most commonly triggered by antibiotics (particularly penicillins), insect venoms, foods such as peanuts, shellfish, and tree nuts, latex, vaccines, and monoclonal antibody therapies. Non–IgE-mediated reactions may occur with iodine-based contrast agents, opiates, and vancomycin.
Special Considerations In Children: Food allergens—especially milk, egg, wheat, soy, and peanuts—are the most frequent triggers, and even trace exposures may provoke severe reactions.


Clinical Manifestations
Symptoms typically begin within minutes of antigen exposure. Skin and mucosal involvement is present in the vast majority of cases, with urticaria, erythema, pruritus, and angioedema being common. Patients may report an early sense of impending doom. Respiratory findings range from nasal congestion to bronchospasm and upper airway edema. Cardiovascular involvement may include hypotension, arrhythmias, or myocardial ischemia. Gastrointestinal symptoms such as nausea, vomiting, and diarrhea may occur, along with ocular irritation, neurologic symptoms including seizures, and, rarely, hematologic abnormalities such as coagulopathy.


Key Historical Features
Diagnosis is clinical. A focused history should identify prior allergic reactions, known triggers, and recent exposures to foods, medications, or environmental allergens.


Physical Examination Focus
Findings usually involve two or more organ systems, commonly the skin, respiratory tract, gastrointestinal tract, or cardiovascular system. Airway compromise or hypotension may not be present initially but can develop rapidly.


Essential Clinical Assessment
Anaphylaxis is diagnosed on clinical grounds, and early recognition is critical. Ancillary testing should not delay treatment. ECG monitoring is advised in patients with cardiac history, ischemic symptoms, or advanced age.


Diagnostic Evaluation
Laboratory studies are generally not useful in the acute setting. Serum tryptase levels may aid retrospective confirmation. Chest radiography may show hyperinflation in cases with bronchospasm.


Alternative Diagnoses To Consider
Conditions that may mimic anaphylaxis include pulmonary embolism, acute coronary syndromes, asthma, airway obstruction, vasovagal syncope, hereditary angioedema, systemic mastocytosis, hypoglycemia, carcinoid syndrome, and foreign body aspiration.


Prehospital Care Principles
Early airway assessment, oxygen supplementation, IV access, and continuous monitoring are essential. Intramuscular epinephrine should be administered promptly, even before IV access is obtained. Progressive laryngeal edema may necessitate early airway intervention.


Immediate Stabilization Measures
Airway protection and adequate ventilation take priority. Orotracheal intubation is preferred when airway compromise is anticipated. Advanced airway techniques may be required in the presence of significant edema. Epinephrine may be administered via IM, IV, or endotracheal routes, along with aggressive fluid resuscitation.


Emergency Department Management
Continuous cardiac and vital-sign monitoring is required. Persistent bronchospasm is treated with inhaled β2-agonists. Hypotension is addressed with IV fluids and vasopressors if needed. Antihistamines reduce histamine-mediated effects, corticosteroids help prevent biphasic reactions, and glucagon is indicated for epinephrine-resistant anaphylaxis in patients taking β-blockers.


Pharmacologic Therapy
First-line therapy includes intramuscular epinephrine, H1 antihistamines, corticosteroids, and inhaled bronchodilators. Second-line agents include racemic epinephrine, H2 blockers, and glucagon when indicated. Special caution is required in patients receiving β-blockers.


Disposition Planning
Patients requiring intubation or ongoing respiratory or hemodynamic support should be admitted to an intensive care setting. Those with persistent or severe reactions warrant inpatient observation due to the risk of biphasic reactions. Patients with complete symptom resolution may be discharged after a period of observation.


Post-Discharge Follow-Up
All patients should receive early outpatient follow-up, ideally with an allergist. Education regarding trigger avoidance and prescription of self-injectable epinephrine are essential. Patients should be instructed on proper auto-injector use and advised to carry it at all times.


Clinical Pearls And Pitfalls
Delayed recognition of anaphylaxis can result in rapid airway compromise and cardiovascular collapse. Early administration of epinephrine is the single most critical intervention. Patients with a prior history of anaphylaxis require education on avoidance strategies and prompt self-treatment to prevent fatal outcomes.

Emergency And Acute Medicine – Anemia


Core Definition
Anemia refers to a reduction below normal in total red blood cell (RBC) mass. It is most commonly identified by decreased hemoglobin concentration, hematocrit, or RBC count. Normal reference values vary with age, sex, altitude, and physiologic state. Because hemoglobin and hematocrit reflect concentrations, values may fall due to reduced RBC mass or increased plasma volume. Importantly, anemia is never a normal variant and always signifies an underlying disorder or deficiency that requires evaluation.


Causative Mechanisms
The most common cause of anemia is excessive blood loss, including trauma, gastrointestinal hemorrhage, and menstruation. Increased RBC destruction (hemolysis) may occur due to hypersplenism, autoimmune processes, mechanical injury, toxins, infections, or inherited membrane and enzyme defects. Reduced RBC production results from impaired bone marrow function or deficiencies and is commonly classified by RBC size into microcytic, macrocytic, or normocytic patterns.


Clinical Presentation
Symptoms depend on the severity, chronicity, and speed of onset. Acute anemia may produce hypovolemia, whereas chronic mild anemia may be asymptomatic. Common complaints include fatigue, reduced exercise tolerance, dyspnea on exertion, chest pain, syncope, and signs of bleeding. Physical findings may include pallor, tachycardia, murmurs, orthostatic hypotension, jaundice, splenomegaly, neurologic deficits, or nail and skin changes that reflect the underlying cause.


Initial Evaluation
A focused history should assess bleeding, chronic disease, nutritional status, medication use, and family history. Vital signs and orthostatic measurements are essential. The primary goals are to determine whether anemia is due to blood loss, hemolysis, or impaired RBC production and to assess hemodynamic stability.


Laboratory Assessment
Initial testing includes a complete blood count with RBC indices, reticulocyte count, and peripheral smear. Reticulocyte response helps distinguish between underproduction and increased destruction or loss. Additional studies may include iron studies, vitamin B12 and folate levels, renal function tests, hemolysis markers, stool occult blood testing, and specialized assays such as hemoglobin electrophoresis when indicated.


Diagnostic Considerations
Patterns of anemia guide further evaluation. Microcytic anemia suggests iron deficiency or thalassemia; macrocytic anemia raises concern for vitamin deficiencies, liver disease, or marrow disorders; normocytic anemia may indicate acute blood loss, chronic disease, renal failure, or marrow suppression. Bone marrow biopsy is reserved for selected cases involving suspected marrow pathology.


Differential Diagnoses
Important considerations include acute blood loss, anemia of chronic disease, hemolysis, malignancy, nutritional deficiencies, bone marrow failure, and dilutional anemia. Age-specific factors apply in pediatric, pregnant, and elderly populations.


Emergency Management
Immediate treatment is dictated by severity and stability. Patients with ongoing hemorrhage or hemodynamic compromise require airway support, oxygen, IV access, crystalloid resuscitation, and transfusion when indicated. Most chronic anemias identified in the emergency department do not require urgent intervention.


Definitive Therapy
Management targets the underlying cause. Iron supplementation is used for iron deficiency, erythropoietin for renal failure–associated anemia, corticosteroids or immunosuppression for autoimmune hemolysis, vitamin replacement for nutritional deficiencies, and disease-specific therapies for hematologic malignancies or hemoglobinopathies.


Disposition And Follow-Up
Admission is required for unstable patients, those with symptomatic or severe anemia, ongoing blood loss, or need for transfusion. Stable patients may be discharged with clear outpatient follow-up for diagnostic evaluation and treatment. Newly diagnosed anemia always warrants further investigation.


Clinical Insights And Common Errors
Anemia is a sign, not a diagnosis, and its cause must be identified. Life-threatening cases require rapid correction, while most emergency department presentations represent chronic disease. Failure to recognize occult bleeding or hemolysis and assuming anemia is benign are frequent pitfalls.

Emergency And Acute Medicine – Angioedema


Core Description
Angioedema is a nonpruritic, well-demarcated, nonpitting swelling of the deeper dermis and subcutaneous tissues caused by increased vascular permeability. It results from inflammatory mediator release, either mast cell mediated or kinin mediated through bradykinin and complement pathways. Unlike urticaria, angioedema affects deeper tissues with fewer mast cells and nerve endings, leading to minimal itching. In addition to the skin, angioedema may involve the gastrointestinal tract and upper airway, and it may occur with or without associated urticaria.


Pathophysiologic Mechanisms
Hereditary and acquired forms of angioedema are related to quantitative or functional deficiencies of C1 esterase inhibitor (C1-INH), resulting in unregulated bradykinin activity. Hereditary angioedema is an autosomal dominant disorder with multiple genetic variants, while acquired forms are associated with lymphoproliferative or autoimmune disease. Angiotensin-converting enzyme inhibitor–related angioedema is common in emergency settings and may occur early or years after initiation of therapy.


Underlying Causes
Kinin-mediated etiologies include hereditary angioedema, acquired C1-INH deficiency, and ACE inhibitor–associated reactions. Mast cell–mediated causes include food allergies, medication reactions, insect stings, and physical triggers such as exercise, temperature changes, or trauma. Idiopathic recurrent angioedema and autoimmune-associated forms are also recognized.


Clinical Features
Patients typically present with sudden, asymmetric swelling of the lips, eyelids, face, tongue, or extremities. Lesions are large, nonpitting, and nonpruritic. Abdominal involvement may cause severe pain, nausea, vomiting, or diarrhea. Airway involvement involving the pharynx or larynx is the most dangerous manifestation and may progress rapidly. Attacks of hereditary angioedema are notably not associated with urticaria or itching.


History And Physical Assessment
A careful history should assess family history, recurrent episodes, recent medication use (especially ACE inhibitors), food exposures, and prior similar events. Emotional stress or minor trauma may precipitate attacks. Physical examination focuses on identifying airway compromise, facial and oropharyngeal swelling, and abdominal tenderness. Lesions typically spare gravity-dependent areas.


Diagnostic Approach
Angioedema is primarily a clinical diagnosis. A family history may be absent, as new mutations account for a significant proportion of hereditary cases. Laboratory testing may support the diagnosis but is not required acutely.


Laboratory And Specialized Testing
Basic studies may include a complete blood count and inflammatory markers. Complement levels such as C4 are often reduced during attacks in hereditary and acquired forms. Measurement of C1-INH levels and function confirms hereditary angioedema but is rarely available in the emergency department. Skin biopsy is rarely required.


Differential Considerations
Conditions that may mimic angioedema include superior vena cava syndrome, heart failure, nephrotic syndrome, facial cellulitis, contact dermatitis, autoimmune connective tissue diseases, hypothyroidism, and facial lymphedema.


Emergency Management Principles
Early airway protection is the priority in all cases. Intravenous access and close monitoring are essential. Epinephrine, antihistamines, and corticosteroids are commonly used when mast cell–mediated angioedema is suspected, though response may be limited in bradykinin-mediated disease. Early intubation should be strongly considered if there is progressive airway involvement.


Targeted Therapy
Hereditary and acquired angioedema may require C1-INH replacement, bradykinin receptor antagonists, or kallikrein inhibitors. Fresh frozen plasma may be used when specific agents are unavailable, though caution is advised. ACE inhibitor–induced angioedema requires immediate discontinuation of the offending drug.


Disposition And Follow-Up
Patients with airway involvement or persistent systemic symptoms require admission and monitored care. Those with mild, nonprogressive symptoms may be discharged after observation with antihistamines, steroids, and clear return precautions. Referral to an allergist or immunologist is recommended for recurrent, hereditary, or unexplained cases.


Clinical Pearls And Pitfalls
Airway compromise can evolve rapidly and unpredictably, necessitating early intervention. Standard allergic therapies may be ineffective in bradykinin-mediated angioedema. Recognition of hereditary angioedema and ACE inhibitor–related cases is critical to avoid delayed or ineffective treatment.

Emergency And Acute Medicine – Amenorrhea


Core Overview
Amenorrhea refers to the absence of menstruation. Primary amenorrhea is defined as the absence of spontaneous uterine bleeding by age 16 years or within 5 years of breast development, which normally begins by age 13. Secondary amenorrhea is the absence of uterine bleeding for 3 months in a woman with previously regular menses or for 9 months in a woman with prior oligomenorrhea. Secondary amenorrhea is more common, and pregnancy is the most frequent cause encountered in emergency care.


Underlying Causes
Primary amenorrhea is most commonly due to gonadal failure, hypothalamic–pituitary disorders, chromosomal abnormalities, structural abnormalities such as imperforate hymen, or conditions such as Turner syndrome. Secondary amenorrhea is frequently related to pregnancy, lactation, or the postpartum state. Other causes include Asherman syndrome, dysfunction of the hypothalamic–pituitary–ovarian axis, polycystic ovarian syndrome, endocrinopathies, extremes of body weight, intense physical exercise, medications, autoimmune disease, ovarian failure, and menopause.


Clinical Features
History should focus on age at menarche, menstrual pattern, sexual activity, exercise habits, weight change, chronic illness, medication use, prior chemotherapy or CNS radiation, family history, and infertility. Physical examination may reveal signs of low estrogen such as atrophic vaginal mucosa and mood changes, or signs of hyperandrogenism including truncal obesity, hirsutism, acne, and male-pattern baldness. Thyroid examination, pelvic or genital examination, and Tanner staging are essential components of assessment.


Essential Emergency Evaluation
A pregnancy test is mandatory in all patients presenting with amenorrhea. If pregnancy testing is negative and the patient is otherwise stable, no additional emergent testing is typically required in the emergency department.


Diagnostic Testing
If pregnancy is excluded, further laboratory evaluation such as TSH, prolactin, LH, and FSH can be deferred to outpatient follow-up with gynecology or primary care. Imaging is not required emergently unless there is concern for ectopic pregnancy or another acute process based on the patient’s presentation. No diagnostic procedures are typically required in the emergency setting.


Conditions To Differentiate
Pregnancy must always be excluded first, including ectopic pregnancy when clinically suspected.


Emergency Department Management
Prehospital care is supportive. If amenorrhea is related to pregnancy, management should follow pregnancy-specific protocols. In the emergency department, treatment consists primarily of reassurance, patient education, and appropriate referral for outpatient evaluation.


Disposition And Follow-Up
Admission is not required unless there is concern for ectopic pregnancy or another emergent condition. Most patients can be safely discharged with referral to gynecology. Follow-up with a gynecologist is recommended for definitive evaluation and management.


Key Clinical Lessons And Common Errors
Pregnancy is the most important and common cause of amenorrhea in the emergency department and must always be ruled out. Urine pregnancy testing may yield false-negative results in dilute urine or early pregnancy, and serum testing should be considered when clinical suspicion is high, particularly for ectopic pregnancy. Eating disorders such as anorexia nervosa should be considered, especially in adolescents presenting with amenorrhea.
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Emergency and Acute Medicine – Acute Coronary Syndrome: Coronary Vasospasm (Prinzmetal / Variant Angina)


Overview and Pathophysiology
Coronary vasospasm causes spontaneous episodes of myocardial ischemia due to transient constriction of coronary arteries without an increase in myocardial oxygen demand. Also known as Prinzmetal or variant angina, it was first described in 1959 and most commonly affects younger patients and men. Many patients lack traditional coronary artery disease (CAD) or classic cardiac risk factors. Cigarette smoking is the strongest association, present in up to three-quarters of cases. Hypertension, hypercholesterolemia, diabetes mellitus, and cocaine use further increase risk.


Mechanisms and Etiology
The underlying mechanism is abnormal coronary vasomotor regulation, typically related to endothelial dysfunction. Vasospasm may involve epicardial arteries, the microvasculature, or both, and can be categorized as focal (localized to a single segment), multifocal (multiple segments of one artery), or multivessel (involving different coronary arteries). Proposed contributors include unopposed α-adrenergic sympathetic stimulation, altered autonomic tone (including increased vagal influence or abrupt vagal withdrawal), hypersensitivity to vasoconstrictor mediators, impaired nitric oxide signaling, and increased Rho-kinase activity in vascular smooth muscle.


Clinical Presentation
Chest pain is classically retrosternal, may radiate to the neck, jaw, left shoulder, or arm, and typically occurs at rest, often at night or in the early morning. Episodes may be prolonged compared with exertional angina and can be associated with palpitations, presyncope, or syncope. Some patients have comorbid migraine headaches or Raynaud phenomenon. Symptoms may be triggered by cold exposure, emotional stress, hyperventilation, or—less commonly—exercise, and often demonstrate a circadian pattern.


Initial Evaluation
The physical examination is usually unrevealing. An ECG is mandatory in all suspected cases. Further testing depends on the clinical context, risk profile, and response to therapy.


Electrocardiography and Testing
During active spasm, the ECG characteristically shows transient, often marked ST-segment elevation, frequently with reciprocal changes. This may be followed by ST depression or T-wave inversion after resolution. Dysrhythmias can occur during spasm, including ventricular tachycardia (often with LAD involvement) or heart block (commonly with right coronary artery spasm).
Cardiac biomarkers (troponin, CK-MB) are usually normal but should be obtained to assess for myocardial injury, especially if symptoms are prolonged. Toxicology screening is helpful when cocaine use is suspected. Chest radiography assists in excluding alternative diagnoses (e.g., pneumothorax, pneumonia, aortic pathology). Noninvasive imaging is most informative when paired with provocative testing. Coronary angiography often reveals mild or absent atherosclerosis; provocative testing with acetylcholine is the diagnostic gold standard in selected patients.


Differential Diagnosis
Consider typical angina, myocardial infarction, aortic dissection, cocaine-associated chest pain, esophageal spasm or rupture, GERD, pericarditis, pulmonary embolism, pneumothorax, Takotsubo cardiomyopathy, anxiety disorders, and musculoskeletal pain.


Emergency Management
Prehospital and initial ED care should follow standard ACS protocols: IV access, cardiac monitoring, oxygen as needed, and vital sign surveillance. Nitroglycerin is effective for symptom relief in vasospastic and ischemic pain and should be administered.
All patients with possible ischemic chest pain typically receive aspirin on arrival; however, aspirin may paradoxically worsen vasospasm by inhibiting prostacyclin synthesis. Despite this, aspirin is commonly given until vasospasm is confirmed. Calcium-channel blockers (CCBs) are first-line therapy for suspected vasospasm. Heparin and β-blockers are not beneficial in isolated vasospasm; β-blockers may worsen symptoms due to unopposed α-mediated vasoconstriction and should be avoided, particularly with cocaine exposure.


Pharmacologic Therapy
First-line treatment includes CCBs (e.g., diltiazem or verapamil) and long-acting nitrates. Despite therapy, 30–40% of patients experience recurrence. Second-line options include α-blockers and statins. Percutaneous intervention for fixed lesions is controversial and may provoke spasm elsewhere. Pacemaker implantation may be indicated for recurrent syncope or AV block related to vasospasm.


Disposition and Follow-Up
Patients with new-onset chest pain or positive biomarkers/provocative testing should be admitted. Many stable patients can be evaluated safely in a chest pain observation unit. Discharge may be appropriate for patients with chronic symptoms and a negative ischemic evaluation. Cardiology follow-up within 7 days is recommended.


Clinical Pearls and Pitfalls
Five-year survival approaches 95%. Most patients lack traditional CAD risk factors aside from smoking. Calcium-channel blockers are the cornerstone of therapy, yet recurrence is common. Vasospasm can mimic STEMI; true infarction usually occurs in those with underlying atherosclerosis. Avoid β-blockers, which can exacerbate spasm. Prolonged episodes may lead to malignant arrhythmias or sudden death.

Emergency and Acute Medicine – Pediatric Abuse (Nonaccidental Trauma, NAT)


Overview and Scope
Pediatric abuse, also referred to as nonaccidental trauma (NAT), represents a major public health concern in the United States. It affects an estimated 2–3% of children annually, with millions impacted each year. Mortality from child maltreatment remains significant, with the majority of deaths occurring in children younger than five years, and infants accounting for a large proportion. All health care professionals are legally mandated reporters of suspected child abuse or neglect. Importantly, abuse occurs across all socioeconomic, cultural, and religious groups.


Risk Factors
Risk factors span the child, caregiver, and family environment. Children at highest risk are typically younger than four years, particularly infants, premature babies, multiples, and those with physical, developmental, or special health care needs.
Caregiver-related risk factors include a history of being abused, poor impulse control, violent behavior, mental illness, substance use, rigid or unrealistic expectations of the child, low self-esteem, and young parental age.
Family-level risk factors include financial stress, social isolation, frequent relocation, marital instability, unwanted pregnancy, and poor parent–child bonding.


Clinical Presentation and History
A hallmark of NAT is a history that is inconsistent with the reported injury or illness. Red flags include unexplained injury, apnea, ingestion, recurrent trauma, or death. Caregivers may be reluctant to provide information, deny knowledge of the injury, or offer changing or implausible explanations. Discrepancies between different caregivers are common.
In some cases, the described mechanism is developmentally impossible for the child. Delays in seeking medical care and inappropriate caregiver responses to the child’s condition are particularly concerning.
Failure to thrive may signal neglect, often related to inadequate caloric intake or impaired caregiver bonding. Munchausen syndrome by proxy should be considered in children with recurrent unexplained illness or suspicious metabolic abnormalities. Reviewing prior emergency department visits and communication with the primary care provider can reveal concerning patterns.


Physical Examination Findings
Physical findings often do not match the provided history. Cutaneous injuries are common and may include bruises with regular patterns, sharp demarcations, finger marks, slap marks, bite marks, burns from cigarettes or immersion (“stocking,” “glove,” or doughnut-shaped buttock burns), and injuries in unusual locations such as the buttocks, hips, face (excluding the forehead), back, thighs, genitalia, or pinna.
Bruises may be present at different stages of healing. While color alone is unreliable for precise dating, the presence of multiple injuries of varying age is suspicious.
Skeletal injuries are frequently multiple and unexplained, often in different stages of healing. Highly concerning findings include classic metaphyseal lesions, posterior rib fractures, fractures crossing suture lines, spiral fractures of long bones, subperiosteal new bone formation, and fractures of uncommon sites such as the scapula, sternum, vertebrae, or spinous processes without adequate mechanism.


Central Nervous System and Ocular Findings
Head injury is the leading cause of death in abused children. Findings may include altered mental status, seizures, skull fractures (particularly in children younger than one year), subdural or subarachnoid hemorrhage, and features consistent with shaken infant injury involving rotational and shearing forces.
Ocular findings are critical clues. Retinal hemorrhages—often bilateral—are present in the majority of abusive head injuries and are rare in accidental trauma without significant head injury. Additional findings may include hyphema, corneal abrasions, or conjunctival hemorrhage.


Abdominal, Genitourinary, and Sexual Abuse Findings
Abusive abdominal trauma may involve lacerations of solid organs, intramural bowel hematomas (especially duodenal), or retroperitoneal hemorrhage.
Anogenital findings such as contusions, erythema, lacerations, scarring, foreign material, sexually transmitted infections, or pregnancy in a child younger than twelve years strongly suggest sexual abuse. Unexplained death must always raise concern for NAT.


Essential Evaluation and Legal Responsibilities
When abuse is suspected, clinicians are legally required to make a formal oral and written report to the appropriate child protection agency. Certainty is not required—reasonable suspicion is sufficient.
Evaluation should include a thorough medical assessment, detailed documentation of findings, and photographic or diagrammatic recording of injuries when appropriate. Family, social, and environmental assessments are typically conducted in coordination with child welfare services.


Diagnostic Testing and Imaging
Laboratory studies are guided by presentation. A bleeding disorder screen is appropriate when bruising is prominent or recurrent. In cases of significant trauma, laboratory evaluation may include complete blood count, liver enzymes, pancreatic enzymes, and urinalysis. Toxicology and metabolic testing are indicated in children with altered mental status.
Imaging plays a central role. A full skeletal survey is recommended for children younger than two years and selectively for older children when abuse is strongly suspected. Additional imaging is obtained based on clinical findings, including abdominal CT for suspected visceral injury and neuroimaging for suspected head trauma. MRI serves as a valuable adjunct for detecting shear injury, evolving hemorrhage, and hypoxic-ischemic changes.


Differential Diagnosis
Conditions that may mimic abuse must be carefully considered, including accidental trauma, birth-related injuries, infections, dermatologic conditions, hematologic or oncologic disorders, bleeding diatheses, nutritional deficiencies, metabolic or genetic bone disease, cultural healing practices, intoxications, metabolic derangements, epilepsy, and sudden infant death syndromes. Differentiation relies on correlation of clinical findings with history, development, and investigative results.


Emergency Department Management
Medical stabilization and trauma care take priority. Clinicians must maintain a nonjudgmental approach while ensuring mandatory reporting and rapid involvement of child protection services. Communication with caregivers should emphasize concern for the child’s safety and well-being. Security may be required in some situations. All siblings and other children in the household must also be evaluated within an appropriate timeframe.


Disposition and Follow-Up
Admission is indicated for traumatic injuries requiring observation or intervention, or when safe disposition cannot be assured. Discharge is considered only after a complete evaluation, confirmation of a safe environment, and coordination with child welfare authorities. Many children require protective placement, including foster care, to prevent further harm.


Clinical Pearls and Pitfalls
A history that does not align with physical findings should immediately raise concern for nonaccidental trauma. When child abuse is suspected, reporting is mandatory and time-sensitive. The primary goal in all cases is ensuring the safety of the child and any siblings.

Emergency and Acute Medicine – Elder Abuse


Overview and Definition
Elder abuse encompasses a spectrum of harmful behaviors directed toward older adults, typically by individuals on whom they depend for care or support. Abuse may be emotional, including insults, humiliation, threats of abandonment, or institutionalization. Physical and sexual abuse involves acts such as hitting, slapping, pushing, burning, inappropriate restraint, or forced sexual activity. Material or financial exploitation includes theft, coercion, or misuse of an elder’s money or property. Neglect refers to acts or omissions by a caregiver or the patient that compromise health or safety, including failure to provide adequate nutrition, shelter, hygiene, or medical care.


Epidemiology and Impact
In the United States, an estimated 1–2 million adults aged 65 years or older are mistreated annually, a figure expected to rise as the population ages. Neglect accounts for the majority of cases, followed by physical mistreatment, financial exploitation, and emotional abuse; sexual abuse is reported less frequently. Family members—most often spouses or adult children—are responsible in approximately 90% of cases. Financial exploitation is particularly underreported, with many cases never reaching authorities. Even mild forms of abuse are associated with a markedly increased risk of mortality and higher rates of chronic pain, musculoskeletal, gastrointestinal, and psychological disorders.


Etiology and Risk Factors
Abuse often arises from caregiver stress, dependency, mental illness, substance use, or financial reliance on the elder. Victim-related factors include physical or cognitive impairment, dependence for activities of daily living, and social isolation, all of which increase vulnerability.


Clinical Presentation
Presentations are highly variable and may be subtle. Histories may be inconsistent, vague, or implausible, and discrepancies may exist between accounts provided by the patient and caregiver. Red flags include delays in seeking medical care, previously untreated conditions, inability or unwillingness to meet basic needs, and medication mismanagement such as incorrect dosing, missing prescriptions, or unfilled medications. Behavioral changes in the elder—withdrawal, fearfulness, demoralization, or substance use—may be evident. Concerning caregiver behaviors include controlling interactions, refusal to leave the patient alone with clinicians, poor knowledge of the patient’s condition, or evidence of significant psychosocial stressors.


Physical Examination Findings
Examination may reveal injuries inconsistent with the reported mechanism or injuries at different stages of healing. Suspicious findings include bruises, burns, lacerations, or abrasions in unusual locations such as the inner arms, torso, buttocks, scalp, or genital and rectal areas. Lesions on wrists or ankles may suggest restraint use. Signs of neglect include poor hygiene, dehydration, weight loss, malnutrition, and pressure ulcers.


Essential Evaluation
Assessment should prioritize patient safety and confidentiality. History should be obtained without caregivers present, as many abused elders fear retaliation, institutionalization, or feel shame or responsibility for the abuse. Clinicians should ask directly but sensitively about mistreatment or neglect. Information from caregivers, relatives, friends, or neighbors may provide important context.
Detailed documentation is critical and should include verbatim patient statements, psychosocial history, caregiver dynamics, substance use, prior involvement of adult protective services, and thorough descriptions of physical findings. Photographic documentation of injuries, when appropriate, can be invaluable. A structured safety assessment is essential.


Diagnostic Testing
Laboratory studies, imaging, and procedures should be guided by the patient’s medical condition and suspected injuries. There are no specific tests that diagnose abuse; rather, diagnosis relies on correlation of clinical findings, risk factors, and patient disclosure.


Differential Diagnosis
Elder abuse can present with any chief complaint. Clinicians must distinguish abuse or neglect from medical conditions that may mimic it, such as dehydration, poorly fitting dentures, burns from accidents, ecchymoses related to anticoagulation, insomnia, medication nonadherence, dementia, or depression.


Prehospital Considerations
Emergency medical personnel may observe critical environmental and interpersonal details, including unsafe living conditions, evidence of neglect, or fearful interactions between the elder and caregiver, which should be communicated to the receiving team.


Emergency Department Management
Initial care follows standard priorities, addressing airway, breathing, circulation, and any life-threatening medical or traumatic conditions. Separation of the patient from caregivers may be necessary to allow safe evaluation. Early involvement of social work is essential for safety planning, caregiver respite, and coordination with community resources. Adult protective services should be notified when abuse or neglect is suspected, in accordance with local laws.
Competent elders retain the right to accept or decline treatment or disposition, even when risks remain, underscoring the importance of clear communication and documentation.


Disposition and Follow-Up
Admission is indicated when medical conditions require inpatient care, when the home environment is unsafe, or when additional time is needed to clarify concerns and coordinate protection. Discharge may be considered only after medical issues are addressed and a safe environment is assured through social services or legal intervention.
Many jurisdictions mandate reporting of suspected elder abuse; clinicians must comply with local regulations. Referral for substance use treatment, mental health services, or caregiver support may be appropriate.


Clinical Pearls and Pitfalls
Elder abuse is common, underrecognized, and associated with high morbidity and mortality. Diagnosis often depends on asking directly in a private setting and recognizing subtle patterns rather than relying on a single finding. Failure to separate the patient from caregivers or to document thoroughly can result in missed opportunities for protection and intervention.

Diagnostic Test – Bone Scan (Technetium Pyrophosphate Nuclear Bone Scan)

1. What is this?

A nuclear bone scan using technetium-labeled pyrophosphate is an imaging study used to detect occult disease involving bone.
It is particularly helpful when pathology is not visible on plain radiographs.

2. How does it work?

• Technetium is taken up by osteoblasts
• It is deposited in areas of new bone matrix formation
• Regions with increased osteoblastic activity demonstrate increased radiotracer uptake (“hot spots”)
• Osteoblastic activity is required for a lesion to be detected on bone scan

3. What makes it abnormal?

A bone scan becomes abnormal when there is increased uptake due to:

• Infection
  • Osteomyelitis
• Malignancy
  • Primary bone tumors or metastatic disease

Key limitation:

• Bone scans are highly sensitive but poorly specific
• They often cannot differentiate bone involvement from adjacent soft-tissue infection

4. What is the most accurate test?

• A bone biopsy is the definitive diagnostic test
• It is required to determine the exact etiology of an abnormal bone scan
  • Culture for infection
  • Histology for malignancy

Emergency and Acute Medicine – Skin and Soft Tissue Abscess


Overview and Definition
A skin or soft tissue abscess is a localized collection of pus that is encapsulated by inflamed tissue. Abscesses may develop anywhere on the body and vary widely in size, depth, and microbiology depending on location and patient risk factors. Variants include furuncles, which originate from infected hair follicles and commonly affect the back, axillae, and lower extremities, and carbuncles, which are larger, deeper, and more extensive infections.


Special anatomic locations have distinct considerations. Mammalian bites are typically polymicrobial. Breast abscesses may occur during lactation (puerperal) or due to duct ectasia, with differing microbial patterns. Hidradenitis suppurativa involves chronic abscess formation in apocrine gland–bearing areas such as the groin and scalp. Pilonidal abscesses arise from epithelial disruption in the gluteal cleft, while Bartholin abscesses result from duct obstruction. Perirectal abscesses originate from anal crypts and frequently require operative management. Other important entities include pyomyositis, abscesses related to IV drug use, paronychia, and felons of the distal finger pulp.


Etiology and Risk Factors
Abscess formation usually follows a break in the skin, obstruction of sebaceous or sweat glands, or inflammation of hair follicles. Most abscesses are bacterial, with microbiology reflecting local skin flora. Staphylococcus aureus is the most common pathogen, and community-acquired MRSA is frequently implicated.
Some abscesses may be sterile, particularly in individuals who inject chemical irritants intravenously. Risk factors include immunosuppression, soft tissue trauma, mammalian or human bites, tissue ischemia, IV drug use, and inflammatory bowel disease, particularly in perirectal infections.


Clinical Presentation
Local findings typically include erythema, warmth, swelling, tenderness, and fluctuance. Surrounding cellulitis is common, and regional lymphadenopathy or lymphangitis may occur. Systemic symptoms are often absent in uncomplicated cases. However, patients with extensive infection, necrotizing soft tissue involvement, or bacteremia may present with fever, rigors, hypotension, or altered mental status, indicating sepsis.


History and Physical Examination
History should address prior abscesses, which raise suspicion for MRSA, as well as immunosuppression, medication use (such as chronic steroids or chemotherapy), IV drug use, and recent animal or human bites.
Physical examination focuses on defining the location, size, and depth of infection and identifying associated cellulitis, subcutaneous air, or involvement of deep structures. Abscesses involving high-risk areas—such as the face, neck, hands, feet, perirectal region, or genitalia—require heightened caution and often specialty consultation.


Essential Workup
Diagnosis is primarily clinical. Gram stain and routine cultures are not necessary for simple abscesses in otherwise healthy individuals. Wound cultures may be useful when systemic antibiotics are planned, in recurrent infections to document MRSA, in immunocompromised hosts, in abscesses involving the face or hand, or when initial therapy fails.


Diagnostic Testing
Routine laboratory testing is generally unnecessary. Blood glucose measurement may be helpful when undiagnosed diabetes or diabetic ketoacidosis is suspected. In febrile or systemically ill patients, or those with recent IV drug use, blood cultures, lactate, renal function tests, and creatine kinase (if myositis is suspected) are appropriate.
Bedside ultrasound is valuable for differentiating cellulitis from abscess. CT or MRI may be needed to assess deep tissue involvement, while plain radiographs can detect gas in tissue planes.


Differential Diagnosis
Conditions that may mimic abscess include cellulitis, necrotizing fasciitis, hematoma, cysts, and aneurysm, particularly in IV drug users.


Initial Stabilization
Patients with signs of sepsis require prompt IV access, oxygen, crystalloid resuscitation, blood cultures, lactate measurement, and early broad-spectrum antibiotics with MRSA coverage. Rapid source control through drainage is essential.


Definitive Management
Incision and drainage is the cornerstone of abscess treatment. The incision must be sufficiently deep to allow complete evacuation, and elliptical incisions help prevent premature closure. Loculations should be gently broken up, and the cavity irrigated thoroughly.
Loose packing is recommended for abscesses larger than 5 cm, in patients with significant comorbidities, or when abscesses involve high-risk locations. For small, uncomplicated abscesses, routine packing is not always necessary.
Routine antibiotics are not required after drainage of uncomplicated abscesses. Antibiotic therapy is indicated in cases of systemic illness, significant cellulitis, facial abscesses with risk of cavernous sinus drainage, mammalian bites, immunocompromised patients, and perirectal abscesses, which generally require operative management.
The loop drainage technique offers a less invasive alternative that facilitates ongoing drainage, simplifies wound care, and often avoids repeat emergency department visits.


Pediatric Considerations
Incision and drainage are painful procedures in children and frequently require procedural sedation and adequate analgesia.


Antibiotic Therapy
Antibiotic selection should be guided by local resistance patterns. Oral agents are used for moderate associated cellulitis, while intravenous antibiotics are reserved for systemic illness or extensive infection. MRSA-active agents are commonly required, and broader coverage is necessary for bites or facial infections.


Disposition and Follow-Up
Admission is indicated for patients with sepsis, immunocompromised status with significant cellulitis, perirectal involvement, or abscesses requiring operative debridement.
Most patients with uncomplicated abscesses can be discharged after incision and drainage with close outpatient follow-up.


Follow-Up Care
Patients should return in 24–48 hours for wound reassessment and packing removal if used. Warm soaks are recommended for several days after packing removal to promote continued drainage.


Clinical Pearls and Pitfalls
Recurrent abscesses should prompt consideration of community-acquired MRSA. Adequate pain control is essential during drainage procedures. Always assess for deeper infections such as tenosynovitis or deep fascial space involvement, particularly in hand infections.