Treatment of Bacterial Tonsillitis
For confirmed bacterial (Group A Streptococcus) tonsillitis, prescribe penicillin V 250 mg four times daily (or 500 mg twice daily) for a full 10 days, or amoxicillin 50 mg/kg once daily (maximum 1,000 mg) for 10 days as first-line therapy. 1, 2, 3
Diagnostic Confirmation Required Before Treatment
- Always perform rapid antigen detection testing (RADT) and/or throat culture before initiating antibiotics to distinguish bacterial from viral etiology 2, 3, 4
- Bacterial tonsillitis presents with sudden onset sore throat, fever >38°C, tonsillar exudates, tender anterior cervical lymphadenopathy, and absence of cough 1, 2, 4
- Do not prescribe antibiotics for viral tonsillitis—provide supportive care only with ibuprofen or acetaminophen for pain control 2, 3
First-Line Antibiotic Therapy (Non-Allergic Patients)
- Penicillin V remains the gold standard: 250 mg four times daily or 500 mg twice daily for 10 days in adolescents/adults 1, 4
- Amoxicillin is an acceptable alternative: 50 mg/kg once daily (maximum 1,000 mg) for 10 days, particularly useful in younger children due to better taste and suspension availability 1, 2, 3
- The full 10-day course is mandatory—shorter courses increase treatment failure risk and do not adequately prevent rheumatic fever 1, 2, 4
- Standard-dose penicillin for 5 days shows inferior microbiological eradication compared to 10 days (though high-dose penicillin four times daily for 5 days may be non-inferior) 1
Treatment for Penicillin-Allergic Patients
Non-Anaphylactic Penicillin Allergy
- First-generation cephalosporins are preferred: Cephalexin 20 mg/kg twice daily (maximum 500 mg per dose) for 10 days 1, 4
- Cefadroxil 30 mg/kg once daily (maximum 1 g) for 10 days is an alternative 1
Anaphylactic Penicillin Allergy
- Clindamycin 7 mg/kg three times daily (maximum 300 mg per dose) for 10 days 1, 4
- Azithromycin 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 5
- Clarithromycin 7.5 mg/kg twice daily (maximum 250 mg per dose) for 10 days 1
- Important caveat: Macrolide resistance in Group A Streptococcus varies geographically and temporally, making clindamycin the safer choice when resistance patterns are unknown 1
Management of Recurrent Tonsillitis
When Antibiotics May Be Considered for Recurrent Cases
- For patients with recurrent tonsillitis who fail standard penicillin therapy, consider clindamycin or amoxicillin-clavulanate as these agents eradicate beta-lactamase-producing bacteria that may "shield" Group A Streptococcus from penicillin 6, 7
- Clindamycin and amoxicillin-clavulanate show superior clinical and microbiological outcomes compared to penicillin in patients with recurrent acute pharyngo-tonsillitis 7
- Beta-lactamase-producing bacteria are recovered from over 75% of tonsils in patients with recurrent infection 6
Chronic Carrier State
- Patients with recurrent pharyngitis and persistent positive Group A Streptococcus tests may be chronic carriers experiencing repeated viral infections 1
- Do not routinely treat chronic carriers with antibiotics unless specific circumstances exist: community outbreak of rheumatic fever, family history of rheumatic fever, excessive patient/family anxiety, or when tonsillectomy is being considered solely for carrier state 1
- For chronic carriers requiring treatment: Clindamycin 20-30 mg/kg/day in three doses (maximum 300 mg per dose) for 10 days 1
Tonsillectomy Consideration
- Consider tonsillectomy only when meeting Paradise criteria: ≥7 well-documented episodes in the preceding year, OR ≥5 episodes per year for 2 consecutive years, OR ≥3 episodes per year for 3 consecutive years 2, 3, 4
- Each episode must be documented with temperature >38.3°C, cervical adenopathy, tonsillar exudate, or positive Group A Streptococcus test 2, 3, 4
- Watchful waiting is appropriate for patients not meeting these criteria, as spontaneous improvement commonly occurs (control groups show reduction to only 0.3-1.17 episodes per year without surgery) 3
Critical Pitfalls to Avoid
- Never initiate antibiotics without confirming Group A Streptococcus infection through testing—most cases are viral and do not benefit from antibiotics 2, 3, 4
- Never prescribe antibiotic courses shorter than 10 days for Group A Streptococcus tonsillitis (except azithromycin 5-day course), as this increases treatment failure and does not adequately prevent rheumatic fever 1, 2, 4
- Never use broad-spectrum antibiotics when narrow-spectrum penicillins are effective for confirmed Group A Streptococcus 2, 3, 4
- Do not perform routine follow-up throat cultures in asymptomatic patients who completed appropriate therapy 4
- Avoid amoxicillin in older children/adolescents with possible Epstein-Barr virus infection due to risk of severe rash 1