What is the recommended treatment for bacterial tonsillitis?

Treatment of Bacterial Tonsillitis

Amoxicillin or penicillin V is the first-choice antibiotic treatment for bacterial tonsillitis, with a full 10-day course required to prevent rheumatic fever and other complications. 1, 2

Diagnostic Considerations

Before initiating treatment, proper diagnosis is essential:

• Use Rapid Antigen Detection Test (RADT) with throat culture backup for negative results in children
• Adults with negative RADTs do not routinely require backup cultures due to lower incidence of Group A Streptococcal (GAS) pharyngitis 2
• Patients with clinical features strongly suggesting viral etiology (cough, rhinorrhea, hoarseness, oral ulcers) should not be tested for strep infection 2
• The Centor Criteria should be used to assess the likelihood of GAS pharyngitis 2

First-Line Treatment

For confirmed or suspected bacterial tonsillitis:

• Amoxicillin: 50 mg/kg once daily (maximum 1000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 2
• Penicillin V: 250 mg four times daily or 500 mg twice daily for 10 days 2

A full 10-day course is critical to prevent acute rheumatic fever, even if symptoms improve earlier 2. This is particularly important as shorter courses have not proven effective in preventing rheumatic fever and glomerulonephritic diseases 3.

Second-Line Treatment Options

For patients with penicillin allergy:

• Cephalexin: Recommended as a second-line antibiotic due to lower relapse rates and good tolerability 1
• Clarithromycin: For patients with severe penicillin allergy, 500 mg once daily for 5 days 1, 2
• Azithromycin: 12 mg/kg once daily (max 500 mg) for 5 days 2, 4
• Clindamycin: 300-450 mg orally three times daily for 10 days 2

Note that azithromycin and clarithromycin offer more convenient dosing and lower rates of gastrointestinal side effects compared to erythromycin 5, but the FDA specifically notes that penicillin remains the drug of choice for treating Streptococcus pyogenes infection and preventing rheumatic fever 4.

Special Considerations

• Bacterial tonsillitis is most commonly caused by Streptococcus pyogenes (Group A Streptococcus) 6
• Penicillin failure rates have increased over time, reaching approximately 30% in some studies 7
• Causes of treatment failure include:
  • Poor compliance with the 10-day regimen
  • Reexposure to infected family members
  • Beta-lactamase-producing bacteria "shielding" GAS by inactivating penicillin 8
  • Elimination of normal protective pharyngeal flora 7, 8

Supportive Care

In addition to antibiotics, supportive care should include:

• NSAIDs (e.g., ibuprofen) for pain and fever
• Adequate hydration
• Rest
• Steroids (e.g., dexamethasone) may help reduce symptoms 3

Prevention and Follow-up

• Diagnostic testing or empiric treatment of asymptomatic household contacts is not routinely recommended 2
• Follow-up cultures after treatment are not routinely needed unless special circumstances exist 2
• Patients should be isolated for a minimum of 24 hours after starting effective antibiotic therapy 2

Complications

Proper antibiotic treatment reduces the risk of complications including:

• Suppurative complications: peritonsillar abscess, acute otitis media, cervical lymphadenitis
• Non-suppurative complications: acute rheumatic fever and acute glomerulonephritis 2

Remember that the primary goal of treatment is to prevent acute rheumatic fever, which requires a full 10-day course of appropriate antibiotics, even if symptoms improve earlier.