What is the management for a patient presenting with possible streptococcal (strep) pharyngitis?

Management of Possible Streptococcal Pharyngitis

For patients presenting with possible strep throat, confirm the diagnosis with rapid antigen detection test (RADT) or throat culture before initiating antibiotics, then treat confirmed cases with penicillin or amoxicillin for 10 days. 1

Diagnostic Approach

Clinical Assessment

• Do not test or treat patients with clear viral features: cough, rhinorrhea, hoarseness, or oral ulcers 1
• Do not test children under 3 years old unless they have specific risk factors (e.g., older sibling with confirmed GAS infection) 1
• Fever, tonsillar exudate, cervical lymphadenitis, and age 3-15 years increase clinical suspicion for streptococcal infection 2

Laboratory Confirmation

• Adults: A negative RADT is sufficient to rule out streptococcal pharyngitis—no backup throat culture needed 1, 3
• Children and adolescents: A negative RADT must be confirmed with throat culture due to 10-20% false negative rate and higher risk of rheumatic fever 1, 3
• RADT specificity is ≥95%, making false positives rare 3
• Proper swabbing technique (posterior pharyngeal wall and both tonsils) is critical for accuracy 3

Treatment for Confirmed GAS Pharyngitis

First-Line Therapy (Non-Allergic Patients)

Penicillin or amoxicillin remains the drug of choice based on narrow spectrum, proven efficacy, safety, and low cost 1

Dosing options:

• Penicillin V: 250 mg twice or three times daily for children; 250 mg three to four times daily or 500 mg twice daily for adolescents/adults, for 10 days 1
• Amoxicillin: 50 mg/kg once daily (maximum 1000 mg) for 10 days—preferred in young children due to better palatability and once-daily dosing 1, 4
• Benzathine penicillin G (intramuscular): Single dose of 600,000 units for patients <27 kg or 1.2 million units for ≥27 kg—consider when adherence is a concern 1

Penicillin-Allergic Patients

For non-anaphylactic penicillin allergy:

• First-generation cephalosporins (cephalexin 20 mg/kg/dose twice daily or cefadroxil 30 mg/kg once daily) for 10 days 1, 5

For immediate/anaphylactic penicillin allergy (avoid all beta-lactams):

• Clindamycin: 7 mg/kg/dose three times daily (maximum 300 mg/dose) for 10 days—preferred due to ~1% resistance rate 1, 5
• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days—acceptable alternative but macrolide resistance is 5-8% in the U.S. 1, 6
• Clarithromycin: 7.5 mg/kg/dose twice daily (maximum 250 mg/dose) for 10 days 1

Critical Treatment Duration

All antibiotics except azithromycin require a full 10-day course to achieve maximal pharyngeal eradication and prevent acute rheumatic fever 1. Treatment can be initiated up to 9 days after symptom onset and still prevent rheumatic fever 3.

Management of Negative Test Results

Withhold antibiotics when RADT (and throat culture in children) are negative 3

Symptomatic Treatment Only

• Acetaminophen or ibuprofen for moderate to severe symptoms or fever control 1, 3
• Avoid aspirin in children due to Reye syndrome risk 1
• Do not use corticosteroids for routine symptomatic management 1
• Most viral pharyngitis resolves within 3-7 days without treatment 3

Important Clinical Pitfalls

Do Not Treat Without Confirmation

• Up to 70% of patients with sore throat receive unnecessary antibiotics, while only 20-30% actually have GAS pharyngitis 3
• Treating based on clinical symptoms alone without laboratory confirmation leads to antibiotic overuse 3

Do Not Test or Treat Household Contacts

• Asymptomatic household contacts should not be tested or treated prophylactically, even with history of recurrent infections 1, 3
• Up to one-third of households include asymptomatic GAS carriers who do not require treatment 1, 3
• Antibiotic prophylaxis has not been shown to reduce subsequent GAS pharyngitis incidence 1

Do Not Perform Routine Post-Treatment Cultures

• Follow-up throat cultures or RADT are not recommended for asymptomatic patients who completed therapy 1
• Consider follow-up testing only in special circumstances (e.g., history of rheumatic fever, outbreak situations) 1

Return to School/Work Timing

• Patients should complete 24 hours of antibiotics before returning to school or daycare 7
• 83% of patients become culture-negative within 24 hours of starting appropriate antibiotics 7

Recurrent Episodes

Consider chronic carrier status in patients with multiple episodes of pharyngitis with positive GAS tests 1

• Chronic carriers are experiencing repeated viral infections, not true recurrent streptococcal pharyngitis 1
• Carriers have persistence of the same GAS strain over time and do not require routine antimicrobial therapy 1
• For single recurrence shortly after treatment, retreat with any appropriate first-line agent 1

When to Treat Carriers (Special Circumstances Only)

• Community outbreak of acute rheumatic fever, glomerulonephritis, or invasive GAS infection 1
• Family or personal history of acute rheumatic fever 1
• Carrier treatment regimens (when indicated): Clindamycin 20-30 mg/kg/day in 3 doses for 10 days, or penicillin plus rifampin combination 1