What is the treatment approach for acute pharyngitis?

Treatment of Acute Pharyngitis

Diagnostic Confirmation Required Before Treatment

Antibiotic therapy should only be prescribed for confirmed Group A Streptococcus (GAS) pharyngitis, as the vast majority of acute pharyngitis cases are viral and self-limiting. 1

Clinical Assessment

• Evaluate for the presence of clinical features suggestive of GAS: fever ≥38°C, tonsillar exudate, tender anterior cervical lymphadenopathy, and absence of cough or rhinitis 1
• Clinical features alone cannot reliably distinguish bacterial from viral causes 2
• Patients with 0-1 clinical criteria should receive symptomatic treatment only without testing 3

Laboratory Confirmation

• Rapid Antigen Detection Test (RADT) is the recommended diagnostic approach - a positive result is diagnostic and does not require backup culture 2
• RADT has high sensitivity (91%) and specificity (95%) for GAS diagnosis 4
• Throat culture is the gold standard but is underutilized due to 1-2 day delay in results 5
• In adults, negative RADT results without culture confirmation is acceptable given the low prevalence of GAS and very low risk of rheumatic fever 1

First-Line Antibiotic Treatment for Confirmed GAS Pharyngitis

Penicillin V oral for 10 days remains the treatment of choice due to proven efficacy, safety, narrow spectrum, and low cost, with no documented penicillin resistance in GAS anywhere in the world. 1, 2

Standard Regimens

• Penicillin V: Standard first-line therapy for 10 days 1, 2
• Amoxicillin: Often used in place of penicillin V, particularly in young children due to better taste acceptance, with equal efficacy 1
• Intramuscular benzathine penicillin G: Single dose recommended for patients unlikely to complete a full 10-day oral course 2

Critical Treatment Duration

• A full 10-day course is essential to achieve maximal pharyngeal eradication of GAS and prevent acute rheumatic fever 2, 6
• Treatment within 9 days of symptom onset effectively prevents acute rheumatic fever 1
• Treatment does not prevent post-streptococcal glomerulonephritis 1

Treatment for Penicillin-Allergic Patients

Non-Anaphylactic Penicillin Allergy

First-generation cephalosporins (cephalexin or cefadroxil) are the preferred first-line alternatives for patients with non-immediate penicillin allergy. 2, 7

• Cephalexin: 20 mg/kg per dose twice daily (maximum 500 mg/dose) for 10 days in children; 500 mg every 12 hours for 10 days in adults 7
• Cefadroxil: 30 mg/kg once daily (maximum 1 gram) for 10 days 7
• Cross-reactivity risk is only 0.1% in patients with non-severe, delayed penicillin reactions 7

Immediate/Anaphylactic Penicillin Allergy

Patients with immediate hypersensitivity reactions (anaphylaxis, angioedema, respiratory distress, or urticaria within 1 hour) must avoid all beta-lactam antibiotics including cephalosporins due to up to 10% cross-reactivity risk. 2, 7

Preferred Alternative: Clindamycin

• Clindamycin: 7 mg/kg per dose three times daily (maximum 300 mg/dose) for 10 days 2, 7
• Approximately 1% resistance rate among GAS in the United States 7
• Demonstrates high efficacy even in chronic carriers 7

Acceptable Alternatives: Macrolides

• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 2, 7
• Clarithromycin: 7.5 mg/kg per dose twice daily (maximum 250 mg/dose) for 10 days 7
• Macrolide resistance is 5-8% in the United States and varies geographically 2, 7
• Azithromycin requires only 5 days due to prolonged tissue half-life 2, 7

Primary Treatment Goals

The primary goal of antibiotic treatment is to prevent acute rheumatic fever and suppurative complications such as peritonsillar abscess. 2

Secondary Benefits

• Reduction of clinical symptoms and duration of illness 2
• Decreased contagiousness and prevention of transmission to close contacts 2
• Rapid disappearance of symptoms (within 3-4 days) 1

Symptomatic Treatment for All Patients

All patients with pharyngitis should receive appropriate symptomatic care regardless of etiology. 1, 3

• Acetaminophen or NSAIDs for pain relief and fever reduction 2
• Aspirin must be avoided in children due to risk of Reye syndrome 2, 7
• Corticosteroids are not recommended as adjunctive therapy 1, 2

Management of Viral Pharyngitis

Viral pharyngitis is self-limiting and requires only symptomatic treatment without antibiotics. 2

• Group C and G streptococci can cause pharyngitis with similar clinical features to GAS but are not associated with acute rheumatic fever 2
• Symptomatic treatment includes analgesics, antipyretics, and supportive care 1, 3

Management of Recurrent Episodes

Distinguishing True Recurrence from Chronic Carriage

• Most patients with multiple episodes are chronic streptococcal carriers experiencing repeated viral infections 1, 2
• Chronic carriers generally do not require antibiotic treatment as they are unlikely to spread GAS and are at little risk for complications 2
• Information about precise symptoms, clinical response to antibiotics, and presence/absence of GAS during asymptomatic intervals helps distinguish persistent carriage from recurrent acute infection 1

Treatment of True Recurrent GAS Pharyngitis

• For single recurrence shortly after completing appropriate therapy, treatment with any agent listed for initial therapy is appropriate 1
• Intramuscular benzathine penicillin G should be considered if adherence to oral therapy is questionable 1
• For true recurrent infections, options include clindamycin, penicillin plus rifampin, or amoxicillin-clavulanate 2

Critical Pitfalls to Avoid

• Do not prescribe antibiotics without laboratory confirmation of GAS - this leads to unnecessary antibiotic use in the 75-90% of cases that are viral 1, 3
• Do not shorten antibiotic courses below 10 days (except azithromycin's 5-day regimen) - this dramatically increases treatment failure and rheumatic fever risk 2, 7
• Do not use cephalosporins in patients with immediate/anaphylactic penicillin reactions due to 10% cross-reactivity risk 2, 7
• Do not use broad-spectrum antibiotics when narrow-spectrum agents are appropriate - this unnecessarily increases cost and selection pressure for resistant organisms 7
• Do not perform routine post-treatment testing in asymptomatic patients who have completed therapy 1, 2
• Do not assume all penicillin-allergic patients cannot receive cephalosporins - only those with immediate/anaphylactic reactions should avoid them 7