What is the recommended treatment, dose, and frequency for a patient with tonsillitis, considering the cause and patient factors such as age, weight, and medical history?

Treatment of Tonsillitis: Antibiotic Selection, Dosing, and Duration

Diagnostic Testing Required Before Treatment

Clinicians must test for Group A Streptococcus (GAS) using rapid antigen detection testing (RADT) and/or throat culture before initiating any antibiotic therapy for suspected bacterial tonsillitis. 1, 2 Testing prevents unnecessary antibiotic use since 70-95% of tonsillitis cases are viral in origin. 3, 4

• Antibiotics should only be prescribed when GAS infection is confirmed by testing 1, 2
• Clinical features suggestive of GAS include: persistent fever >38.3°C (101°F), anterior cervical adenopathy, tonsillopharyngeal exudates, and absence of cough 1
• Viral tonsillitis typically lacks high fever, tonsillar exudate, and prominent cervical lymphadenopathy 2

First-Line Antibiotic Treatment for Confirmed GAS Tonsillitis

For Patients Without Penicillin Allergy

Penicillin V is the gold standard first-line treatment: 250 mg orally 2-3 times daily for children, or 250 mg four times daily or 500 mg twice daily for adolescents and adults, for a full 10-day course. 1, 2

• Amoxicillin is an acceptable alternative: 50 mg/kg once daily (maximum 1000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 1
• Benzathine penicillin G intramuscularly is an option for patients with adherence concerns: <27 kg receive 600,000 units; ≥27 kg receive 1,200,000 units as a single dose 1
• The full 10-day antibiotic course is mandatory to maximize bacterial eradication and prevent rheumatic fever and glomerulonephritis, even though shorter courses may resolve symptoms 2, 5

For Patients With Penicillin Allergy

For non-anaphylactic penicillin allergy, use first-generation cephalosporins: 1, 2

• Cephalexin: 20 mg/kg/dose twice daily (maximum 500 mg/dose) for 10 days 1
• Cefadroxil: 30 mg/kg once daily (maximum 1 g) for 10 days 1

For anaphylactic penicillin allergy, use: 1, 2

• Clindamycin: 7 mg/kg/dose three times daily (maximum 300 mg/dose) for 10 days 1
• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 6
• Clarithromycin: 7.5 mg/kg/dose twice daily (maximum 250 mg/dose) for 10 days 1

Important caveat: Macrolide resistance (azithromycin, clarithromycin) varies geographically and temporally, making them less reliable than beta-lactams 1

Supportive Care for All Patients

All patients with tonsillitis should receive analgesic therapy regardless of etiology: 1

• NSAIDs (ibuprofen), acetaminophen, aspirin (adults only), or throat lozenges for pain relief 1
• Steroids (e.g., dexamethasone) may be considered for symptom reduction in acute tonsillitis 5
• Hydration and supportive care are essential for viral tonsillitis 4

Critical Pitfalls to Avoid

Never initiate antibiotics without confirming GAS infection through testing 1, 2 - this leads to unnecessary antibiotic exposure and promotes resistance.

Never prescribe antibiotic courses shorter than 10 days for GAS tonsillitis 2, 5 - only the 10-day course has proven effective in preventing rheumatic fever and glomerulonephritis, despite shorter courses providing symptom relief.

Never use broad-spectrum antibiotics when narrow-spectrum penicillins are effective for confirmed GAS 2 - this unnecessarily increases resistance patterns and adverse effects.

When to Consider Tonsillectomy

Tonsillectomy may be considered only when meeting Paradise criteria with proper documentation: 1, 2

• At least 7 documented episodes in the past year, OR
• At least 5 episodes per year for 2 consecutive years, OR
• At least 3 episodes per year for 3 consecutive years

Each documented episode must include: temperature >38.3°C, cervical adenopathy, tonsillar exudate, OR positive GAS test 1, 2

Watchful waiting is strongly recommended if frequency criteria are not met 1, 2 - benefits of tonsillectomy are modest and do not persist beyond the first postoperative year.

Follow-Up Considerations

Routine follow-up throat cultures should not be performed for asymptomatic patients who completed appropriate antibiotic therapy 2 - GAS carriers (10% of healthy children) do not require treatment or decolonization. 5

If symptoms persist despite appropriate therapy, consider: 2

• Medication non-compliance
• Chronic GAS carriage with intercurrent viral infections
• Need for alternative antibiotics due to resistance