What are the guidelines for managing strep throat?

Guidelines for Managing Strep Throat

For patients with suspected strep throat, use the Centor criteria to guide testing and treatment decisions: test patients with 2-3 criteria using rapid antigen detection test (RADT), and reserve antibiotics only for those with confirmed Group A Streptococcus (GAS) and 3-4 Centor criteria after weighing benefits against harms. 1

Diagnostic Approach

Clinical Scoring System

Apply the Centor criteria to stratify risk for GAS pharyngitis: 1, 2

• Fever (temperature >38°C)
• Absence of cough
• Tonsillar exudates
• Tender anterior cervical lymphadenopathy

Testing Strategy

• Do NOT test or treat children <3 years old unless special circumstances exist (e.g., older sibling with confirmed GAS), as acute rheumatic fever is rare and classic streptococcal presentation is uncommon in this age group 1

• Patients with 0-2 Centor criteria: Do NOT perform testing or prescribe antibiotics—these presentations are likely viral 1

• Patients with 2-3 Centor criteria: Perform RADT to guide antibiotic decisions 1

• Patients with 3-4 Centor criteria: Perform RADT; if positive, consider antibiotics after discussing modest benefits versus risks 1

Important caveat: Clinical features strongly suggesting viral etiology (conjunctivitis, cough, hoarseness, coryza, diarrhea, anterior stomatitis, discrete ulcerative lesions, or viral exanthem) should prompt you to avoid testing regardless of Centor score 1, 2

Laboratory Testing Details

• RADT is sufficient—throat culture is NOT necessary after a negative RADT for diagnosing GAS 1

• Do NOT perform follow-up post-treatment cultures or RADT routinely; these are only indicated in special circumstances 1

• Do NOT test or treat asymptomatic household contacts of patients with GAS pharyngitis 1

Symptomatic Treatment

Prescribe ibuprofen or acetaminophen (paracetamol) for pain and fever relief—this is strongly recommended for all patients with acute sore throat 1

Avoid aspirin in children due to risk of Reye's syndrome 1

Do NOT use:

• Zinc gluconate 1
• Corticosteroids routinely (may consider only in adults with 3-4 Centor criteria and severe presentation) 1

Antibiotic Treatment

Indications for Antibiotics

Do NOT prescribe antibiotics for: 1

• Patients with 0-2 Centor criteria
• Prevention of suppurative complications (quinsy, acute otitis media, cervical lymphadenitis, mastoiditis, acute sinusitis)
• Prevention of rheumatic fever or glomerulonephritis in low-risk patients without previous history

Consider antibiotics ONLY for patients with: 1

• Confirmed GAS by RADT or culture
• 3-4 Centor criteria
• After discussing that benefits are modest and must be weighed against side effects, antimicrobial resistance, medicalization, and costs

First-Line Antibiotic Regimen

Penicillin V is the drug of choice: 1

Adults and adolescents:

• 500 mg twice daily for 10 days 1
• Alternative: 250 mg three or four times daily for 10 days 1

Children:

• 250 mg twice or three times daily for 10 days 1

Critical point: The full 10-day course is mandatory to prevent acute rheumatic fever, even if symptoms resolve earlier 1, 3

Alternative: Amoxicillin

Amoxicillin is equally effective and often preferred for children due to better taste: 1, 4

Dosing:

• Children: 50 mg/kg once daily (maximum 1000 mg) OR 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 1, 4, 3
• Adolescents and adults: 500 mg twice daily for 10 days 1, 4, 3

Evidence note: Once-daily amoxicillin (50 mg/kg, max 1000 mg) has strong evidence supporting equal efficacy to multiple daily dosing and may improve adherence 1, 5

Intramuscular Option

Benzathine penicillin G (single dose): 1

• <27 kg: 600,000 units
• ≥27 kg: 1,200,000 units

For Penicillin-Allergic Patients

First-generation cephalosporins (avoid if immediate-type hypersensitivity): 1

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

For immediate-type penicillin allergy: 1

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

Critical caveat: Macrolide resistance varies geographically and temporally—use only when necessary and be aware of local resistance patterns 1, 6, 7

Special Situations: Chronic Carriers

Do NOT treat chronic GAS carriers routinely—they are at minimal risk for complications and unlikely to transmit infection 1, 2

Carrier eradication may be considered only in special circumstances: 2

• Community outbreak of acute rheumatic fever, glomerulonephritis, or invasive GAS
• Outbreak in closed community
• Family or personal history of acute rheumatic fever
• Excessive family anxiety
• When tonsillectomy is being considered solely because of carriage

Carrier eradication regimens (if indicated): 2

• Clindamycin 20-30 mg/kg/day in 3 doses for 10 days
• Penicillin V plus rifampin
• Amoxicillin-clavulanate
• Benzathine penicillin G plus rifampin

Common Pitfalls to Avoid

Do NOT:

• Prescribe antibiotics based on clinical presentation alone without microbiological confirmation 1
• Use antibiotics to prevent complications in low-risk patients 1
• Perform throat cultures after negative RADT 1
• Test or treat asymptomatic contacts 1
• Recommend tonsillectomy solely to reduce frequency of GAS pharyngitis 1
• Use shorter antibiotic courses than recommended—insufficient evidence supports this approach 1