Treatment Approach for Acute Pharyngitis
Penicillin V or amoxicillin for 10 days is the first-line treatment for confirmed Group A Streptococcal (GAS) pharyngitis due to proven efficacy, safety, narrow spectrum, and low cost. 1, 2
Diagnostic Approach
- Most cases of acute pharyngitis are viral (70-80% in children, 85-95% in adults), with GAS being the primary bacterial pathogen requiring specific treatment 2, 3
- Clinical features alone cannot reliably distinguish between viral and bacterial causes, necessitating laboratory confirmation 2, 4
- Use modified Centor criteria to assess likelihood of GAS infection: fever, tonsillar exudates, tender anterior cervical adenopathy, and absence of cough 5, 6
- Patients with fewer than 3 Centor criteria do not need testing or antibiotics as the risk of bacterial infection is low 1, 5
- Patients with 3-4 Centor criteria should be tested with rapid antigen detection test (RADT) and/or throat culture to confirm GAS 2, 7
Treatment for Confirmed GAS Pharyngitis
First-Line Treatment
- Penicillin V for 10 days (adults: 250 mg 4 times daily or 500 mg twice daily; children: 250 mg 2-3 times daily) 1, 2
- Amoxicillin for 10 days (50 mg/kg once daily, maximum 1000 mg) is equally effective and often preferred in children due to better taste 1, 8
- The full 10-day course is critical to achieve maximal pharyngeal eradication of GAS and prevent acute rheumatic fever 1, 5
Alternative Antibiotics for Penicillin-Allergic Patients
- For non-anaphylactic penicillin allergy: First-generation cephalosporins (e.g., cephalexin 20 mg/kg twice daily, maximum 500 mg per dose) for 10 days 1, 2
- For anaphylactic penicillin allergy: 1, 5
- Clindamycin (7 mg/kg three times daily, maximum 300 mg per dose) for 10 days
- Azithromycin (12 mg/kg once daily, maximum 500 mg) for 5 days
- Clarithromycin (7.5 mg/kg twice daily, maximum 250 mg per dose) for 10 days
Symptomatic Treatment
- Acetaminophen or NSAIDs for pain relief and fever reduction 5, 6
- Throat lozenges used every two hours can provide effective symptomatic relief 6
- Avoid aspirin in children due to risk of Reye syndrome 9
Benefits and Limitations of Antibiotic Treatment
- Antibiotics shorten symptom duration by only 1-2 days but can prevent complications such as peritonsillar abscess and acute rheumatic fever 1, 5
- Delayed antibiotic prescribing (waiting 48+ hours) is a valid option for less severe cases 1, 5
- The number needed to treat to reduce symptoms is 6 after 3 days of treatment and 21 after 1 week of treatment 1
Common Pitfalls to Avoid
- Treating viral pharyngitis with antibiotics contributes to antimicrobial resistance 5, 10
- Using broad-spectrum antibiotics unnecessarily when narrow-spectrum options are effective 2, 5
- Prescribing antibiotics for asymptomatic carriers of GAS 2, 5
- Routine post-treatment throat cultures are not recommended unless symptoms persist or recur 9
Special Considerations
- Macrolide resistance varies geographically and should be considered when selecting treatment 1, 5
- Corticosteroids provide only a small reduction in symptom duration and are not routinely recommended 5, 6
- For patients unlikely to complete a full 10-day course of oral therapy, intramuscular benzathine penicillin G as a single dose is recommended 1, 2