Diagnosis and Management of Acute Tonsillitis

Diagnostic Approach

The American Academy of Pediatrics and the Infectious Diseases Society of America recommend that patients with sudden onset fever, bilateral tonsillar exudates, and tender anterior and posterior cervical lymphadenopathy should be tested for Group A Streptococcus (GAS) using rapid antigen detection testing (RADT) or throat culture before initiating antibiotic therapy 1, 2
The presence of both anterior and posterior cervical lymphadenopathy is particularly important, as posterior chain involvement raises consideration for infectious mononucleosis (IM) 1
Features that suggest viral etiology rather than GAS include cough, coryza, conjunctivitis, hoarseness, diarrhea, discrete oral ulcerations, and viral exanthem 1, 2, 3

The Centers for Disease Control and Prevention (CDC) and the American Academy of Family Physicians recommend microbiologic confirmation before initiating antibiotics, as clinical diagnosis alone has insufficient accuracy (≤80% predictive value even with scoring systems) 1, 2, 4
Testing options include RADT, which has 90-95% sensitivity, and throat culture on blood agar, which is the gold standard with 90-95% sensitivity but requires 24-48 hours 1, 2

The American Heart Association recommends penicillin V (250 mg orally 2-3 times daily for 10 days) or amoxicillin (500 mg twice daily for 10 days) as first-line treatment for confirmed GAS pharyngitis 2, 3, 4
The full 10-day course is mandatory, as shorter courses have significantly lower bacterial eradication rates and fail to prevent rheumatic fever 2, 3, 4

The Infectious Diseases Society of America and the American Academy of Pediatrics recommend never initiating antibiotics without microbiologic confirmation, as over 50% of acute pharyngitis cases are viral, and empiric treatment leads to unnecessary antibiotic exposure, adverse effects, and resistance 1, 5, 4
Never prescribe antibiotic courses shorter than 10 days for confirmed GAS, as 5-day courses have inadequate bacterial eradication rates and increased risk of rheumatic fever 2, 3
Never use broad-spectrum antibiotics when narrow-spectrum penicillins are effective, as this contributes to antimicrobial resistance without improving outcomes 2, 4