​Kembara Xtra - Medicine - Scarlet Fever

​Kembara Xtra - Medicine - Scarlet Fever 
An illness (mostly affecting children) brought on by group A -hemolytic Streptococcus pyogenes (GAS), which produces erythrogenic toxin, and characterized by fever, pharyngitis, and rash Rash typically appears 24 to 48 hours after the first symptoms appear and spreads quickly throughout the body, starting in the groin, trunk, and axillae with strawberry tongue and circumoral pallor. Rash clears at the end of the first week and is followed by several weeks of desquamation. Rash is not dangerous but is a marker for GAS infection with suppurative and nonsuppurative symptoms.
Head, eyes, ears, nose, throat, skin/exocrine, and afflicted system(s) Similar word(s): scarlatina

Incidence
In wealthy nations, 4- 10% of adults and 15% of school-age children experience GAS pharyngitis each year.
Because of maternal antitoxin antibodies, scarlet fever in infants is uncommon.
Males predominate in the United States among individuals over 12 years old due to high rates (>80%) of lifetime protective antibodies to erythrogenic toxins. Peak age is between 4 and 8 years. 

Prevalence
10% of children with streptococcal pharyngitis develop scarlet fever; GAS accounts for 15–30% of cases of pharyngitis in children and 5–15% in adults.

Pathophysiology and Etiology 

It need the generation of erythrogenic toxin for scarlet fever to occur.
 There are three different categories of toxins: A, B, and C.
Toxins injure capillaries (resulting in rash) and function as superantigens, inducing the release of cytokines.
The primary site of streptococcal infection is typically within the tonsils, but scarlet fever can also occur with infection of the skin, surgical wounds, or uterus (puerperal scarlet fever). Antibodies against toxins reduce formation of rash but do not protect against underlying illness.


Risk factors include a seasonal increase from winter to early spring, a higher prevalence in school-aged children, contact with infected people, and crowded living situations (such as those associated with a lower socioeconomic position, barracks, child care centers, and schools). 

Prevention 
Spread through contact with saliva, nasal secretions, and airborne respiratory droplets Although they are uncommon, foodborne outbreaks have been reported.
Asymptomatic contacts do not require prophylaxis or cultures.
The necessary laboratory tests should be performed on symptomatic contacts of a child with a confirmed GAS infection who have recent or present clinical signs of a GAS infection. If the tests are positive, the contacts should be treated.
Children should wait until they are afebrile and have had 24 hours of antibiotic therapy before going back to school or daycare.

Associated Conditions:Glomerulonephritis, rheumatic fever, impetigo, pharyngitis, and

Prodrome a day or two

Fever (>38°C [100.4°F]), sore throat, headache, myalgias, malaise, and fever
Vomiting and stomach pain (which could mimic an acute abdomen) Rash is a scarlatiniform erythematous punctate eruption. Viral infections are more frequently linked to cough, conjunctivitis, hoarseness, diarrhea, coryza, oral ulceration, and rhinorrhea.

clinical assessment 
Oral examination: beefy red tonsils and throat, with or without exudate; petechiae on the palate; and a white coating on the tongue (appearing between days 1 and 2). By days 4 to 5, this sheds, leaving a red strawberry tongue that is glossy, erythematous, and has noticeable papillae.
Exanthem (appearing in one to five days) - Blurs when squeezed; scarlet, nonconfluent, 1 to 2 mm papules with widespread erythema "Sunburn with goose pimples" is an orange-red, punctate skin eruption with a sandpaper-like texture. Coarse "sand paper" rash that first appears in the groin, upper trunk, and axillae before moving to the extremities is prevalent in skin folds and flexural surfaces (such as the axillae, groin, and buttocks), sparing the palms and soles. - Pale lips, flushed face, and circumoral halo
Pastia lines: transverse red streaks in the skin folds of the abdomen, antecubital space, and axillae. Desquamation. After 7 to 10 days, desquamation starts on the face and spreads over the trunk to the hands and feet. In severe cases, small vesicular lesions (miliary sudamina).


Differential diagnosis includes: infectious mononucleosis; mycoplasma pneumonia; secondary syphilis; toxic shock syndrome; staphylococcal scalded-skin syndrome; Kawasaki disease; acute systemic lupus erythematosus; juvenile arthritis; drug hypersensitivity; severe sunburn. Viral exanthem includes: measles, rubella, roseola, and erythema infectiosum (the fifth disease).

Laboratory Results 
The clinical features of streptococcal and nonstreptococcal pharyngitis overlap too much for a precise diagnosis to be made on those grounds alone. Even patients with all of the clinical signs and symptoms, particularly in children, only have streptococcal pharyngitis 35 to 50 percent of the time.
Use the outcomes of quick tests based on polymerase chain reaction (PCR) or rapid antigen detection testing (RADT).
Modifications to the Centor clinical decision rule
- 1 point for not coughing
- Anterior cervical nodes 1 point are swollen and painful.
- The temperature was 100.4°F (38°C). 1 point
- One point for tonsillar exudate or edema
- From 3 to 14 years of age, 1 point
 Ages between 15 and 44: 0 points; ages over 45: 1 points
 Cumulative score - 0: No additional testing or antibiotics are recommended due to the low risk of GAS pharyngitis (1-2.5%). Risk of GAS pharyngitis is 1: 5-10%; no additional testing or antibiotics are recommended; alternative tests include throat cultures and RADT; if positive, treat. Risk of GAS pharyngitis in groups of two: 11–17%; perform throat cultures or RADT; treat if positive; and 28–35%; perform throat cultures or RADT; treat if positive. - 4+: Risk of GAS pharyngitis is 51-53%; think about empiric antibiotic treatment. Patients who exhibit symptoms that point to a viral cause (such as cough, coryza, diarrhea, conjunctivitis, rhinorrhea, hoarseness, or oral ulcers) should not have testing for GAS pharyngitis done.


Initial examinations (lab, imaging)
RADT: if positive, a diagnostic test with sensitivity similar to culture and 95% specificity. throat culture should be used to confirm a negative RADT in children (adults do not need this step).
Confirmatory culture is not necessary for positive RADT.
PCR: 100% sensitive, 94.1% specific, 84.1% positive predictive value, and 100% negative predictive value when positive. Confirmatory culture is not necessary for positive PCR.
The gold standard for diagnosing streptococcal infection is throat culture (99% specific, 90-97% sensitive; 5-10% of healthy people are carriers).
 Serologic tests (antihyaluronidase, antistreptolysin O titer, and streptozyme testing): Confirm recent GAS infection; neither useful or advised for acute illness diagnosis Gram stain: chains of gram-positive cocci  Elevated WBC count (12,000–16,000/mm3) and eosinophilia later (second week) may be seen on CBC. Follow-up throat cultures or RADT/PCR are not typically advised after treatment.
Asymptomatic household members of patients with acute streptococcal pharyngitis should not typically undergo diagnostic tests or empiric treatment.


Tests in the Future & Special Considerations
Within 5 days of symptoms, antibiotics can delay or abolish the antistreptolysin O response. Recent antibiotic medication may have an impact on culture results.
Interpretation of Tests
Skin lesions show a typical inflammatory response, particularly hyperemia, edema, and infiltration of polymorphonuclear cells.


Management 

Supportive therapy, including the use of analgesic/antipyretic medications like acetaminophen or NSAIDs for moderate to severe symptoms or to reduce fever. Topical anesthetics and pharmaceutical throat lozenges are two options for treating symptoms.

First Line of Medicine
The main goal of treating GAS is to lower the chance of developing acute rheumatic fever. Early intervention reduces the amount of time that symptoms last by one to two days and shortens the contagious period. The best treatment for GAS pharyngitis is penicillin because of its well-established effectiveness, safety, specificity, and affordability.
 Penicillin (PO; penicillin V; etc.) for 10 days - 250 mg PO BID or TID for individuals weighing under 27 kg (60 lb); 250 mg QID or 500 mg BID for individuals weighing over 27 kg (60 lb) Adults and adolescents
- Use penicillin G benzathine: single IM dose 600,000 U for those under 27 kg (60 lb); 1.2 mU for those over 27 kg if compliance is doubtful.  Amoxicillin (PO) 25 mg/kg twice day for 10 days, or 50 mg/kg once daily (maximum dose 1,000 mg) (use only for conclusive GAS as it might cause rash with other viral illnesses). Penicillin allergy is a contraindication. Amoxicillin works similarly to penicillin but is more tolerable to youngsters.
Patients with penicillin allergy (anaphylaxis) should avoid taking this medication.
Next Line
for those with penicillin allergies
Type IV penicillin hypersensitivity Cephalosporins used orally First-generation cephalosporins are less expensive but many are effective:
Cefadroxil 30 mg/kg once daily; maximum 1,000 mg for 10 days Cephalexin 20 mg/kg dose twice daily for 10 days; maximum 500 mg every 12 hours Type I hypersensitivity to penicillin: 12 mg/kg/day (maximum 500 mg) for 5 days of azithromycin (Zithromax, Z pack).
- For clarithromycin (Biaxin), adults should take 250 mg BID for 10 days; children older than 6 months should take 7.5 mg/kg BID.
- For 10 days, provide clindamycin 7 mg/kg (max 300 mg/dose) TID.Sulfonamides and tetracyclines shouldn't be utilized.
ALERT
Due to the possibility of Reye syndrome, youngsters should not take aspirin.


Referral 

Retropharyngeal abscess with peritonsillar abscess; shock symptoms including hypotension, DIC, heart, hepatic, and renal failure

Surgery Tonsillectomy is advised in cases of recurrent pharyngitis (6 positive strep cultures in a year).
Even while children who have had tonsillectomies are less likely to contract infections, such as streptococcal pharyngitis (often known as "strep throat"), the operation does lessen their likelihood.

Follow-Up If there are no symptoms, a follow-up throat culture is not required.
Patient Monitoring Treatment failures usually result from: Poor adherence to approved antibiotic medication -Lactamase oral flora hydrolyzing penicillin GAS carrier status and concurrent viral rash (needs no treatment) Streptococci can remain on unrinsed toothbrushes and orthodontic appliances for up to 15 days, resulting in recurrent exposure to carriers in the family.
Resolve recurring GAS pharyngitis with the same medication, a different oral medication, or intramuscular penicillin G.

No specific diet required

Modification of Lifestyle 
The risk of rheumatic fever is not increased by delaying therapy while waiting for the findings of the culture.
 Finish the antibiotic course completely.
Children shouldn't go back to school or daycare until they've gotten antibiotic therapy for at least 24 hours.
Spreads from person to person. Wash your hands frequently, and avoid sharing utensils.

Treatment reduces symptoms by 12 to 24 hours, however recurrent attacks (caused by other erythrogenic toxins) are possible.

Complications 
Suppurative, sinusitis, otitis media/mastoiditis, cervical lymphadenitis, peritonsillar abscess/retropharyngeal abscess, and pneumonia are among the complications.
Meningitis, brain abscess, osteomyelitis, septic arthritis, endocarditis, cerebral venous sinus thrombosis, and necrotizing fasciitis are a few examples of bacterialemia with metastatic infectious foci. Nonsuppurative - Rheumatic Fever: When treatment is started up to 10 days after the onset of acute GAS infection, it prevents rheumatic fever.
- Glomerulonephritis: caused by a Streptococcus nephritogenic strain; prevention, even after proper GAS treatment, is less definite.
Fever, hypotension, DIC, and heart, liver, and/or renal damage as a result of various toxin-mediated sequelae are all symptoms of the streptococcal toxic shock syndrome. Poststreptococcal reactive arthritis is an aseptic inflammation of one or more joints that occurs after a pharyngeal streptococcal infection with a symptom-free period and usually without cardiac involvement. Cellulitis - Transverse grooves in nail plates and hair loss (telogen effluvium) may appear weeks to months later - Pediatric autoimmune neuropsychiatric disease associated with GAS (PANDAS). There is a certain group of kids whose obsessive-compulsive disorder (OCD) or tic disorders are made worse by GAS infection.

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