What is the recommended diagnostic and treatment approach for pediatric patients with strep (streptococcal) pharyngitis?

Diagnosis and Treatment of Streptococcal Pharyngitis in Pediatric Patients

Diagnostic Approach

Confirm the diagnosis with rapid antigen detection test (RADT) before initiating antibiotics, and if negative in children, follow with throat culture. 1

Testing Strategy

• A positive RADT is diagnostic and does not require backup culture 1
• A negative RADT in children and adolescents must be followed by throat culture to avoid missing cases 2, 1
• Testing is generally not recommended in children younger than three years unless specific risk factors are present 1
• Clinical features alone cannot reliably distinguish streptococcal from viral pharyngitis, making laboratory confirmation essential 2, 1

Clinical Features Suggesting Viral Etiology (No Testing Needed)

• Presence of cough, rhinorrhea, hoarseness, or oral ulcers strongly suggests viral pharyngitis and testing for GAS is not necessary 3

First-Line Treatment for Non-Allergic Patients

For children without penicillin allergy, prescribe oral amoxicillin 50 mg/kg once daily (maximum 1000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days. 2, 1, 4

Alternative First-Line Options

• Oral penicillin V: 250 mg two or three times daily for 10 days in children 2, 1
• Intramuscular benzathine penicillin G (single dose): 600,000 units for children <27 kg or 1,200,000 units for children ≥27 kg 2, 1
• The intramuscular option is preferred when compliance with oral therapy cannot be assured, particularly in populations where rheumatic fever remains prevalent 2, 5

Rationale for First-Line Choices

• Penicillin and amoxicillin remain first-line due to proven efficacy, safety, narrow spectrum of activity, and low cost 1
• All Group A Streptococcus isolates remain sensitive to penicillins 6
• The 10-day duration is essential to prevent acute rheumatic fever, even if symptoms resolve earlier 2, 1, 7

Treatment for Penicillin-Allergic Patients

Non-Anaphylactic Penicillin Allergy

• First-generation cephalosporins are recommended for non-immediate hypersensitivity reactions 1
• Cephalexin: 20 mg/kg twice daily (maximum 500 mg per dose) for 10 days 2, 7
• Cefadroxil: 30 mg/kg once daily (maximum 1 g) for 10 days 2, 7
• Avoid cephalosporins in patients with immediate-type hypersensitivity to penicillin 2

Immediate-Type (Anaphylactic) Penicillin Allergy

• Clindamycin: 7 mg/kg three times daily (maximum 300 mg per dose) for 10 days 2, 1, 7
• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 2, 1, 7
• Clarithromycin: 7.5 mg/kg twice daily (maximum 250 mg per dose) for 10 days 2, 7

Important Caveat About Macrolides

• Resistance of Group A Streptococcus to azithromycin and clarithromycin is well-known and varies geographically and temporally 2
• Consider local resistance patterns when prescribing macrolides 2

Duration and Timing of Therapy

A complete 10-day course is mandatory to prevent acute rheumatic fever, regardless of symptom resolution. 2, 1, 7

• Treatment should be initiated within 9 days of symptom onset to effectively prevent acute rheumatic fever 7
• Continue treatment for a minimum of 48 to 72 hours beyond symptom resolution 4
• At least 10 days of treatment is required for any infection caused by Streptococcus pyogenes to prevent acute rheumatic fever 4

Evidence on Shorter Duration

• While some studies suggest 3-6 days of newer antibiotics may have comparable efficacy, these results must be interpreted with extreme caution in areas where rheumatic heart disease prevalence remains high 8
• Current guidelines still recommend the standard 10-day course to prevent complications like rheumatic fever 1

Adjunctive Symptomatic Treatment

• Acetaminophen or NSAIDs for moderate to severe symptoms or high fever 1, 7, 3
• Aspirin must be avoided in children due to risk of Reye syndrome 1, 7, 3
• Adequate hydration and rest should be encouraged 7
• Warm salt water gargles can provide symptom relief for patients old enough to gargle 3

What NOT to Use

• Corticosteroids are not recommended for routine use in streptococcal pharyngitis 1, 3

Follow-Up and Monitoring

• Routine post-treatment throat cultures are not recommended unless symptoms persist or recur 1, 7
• If symptoms persist beyond 48-72 hours after initiating antibiotics, consider complications or treatment failure 7
• Patients can return to school 24 hours after starting appropriate antibiotic therapy 5

Critical Pitfalls to Avoid

Never treat pharyngitis without confirming streptococcal infection through testing, as clinical features alone are unreliable. 2, 1

• Prescribing antibiotics for viral pharyngitis provides no benefit and contributes to antimicrobial resistance 2, 3
• Avoid broad-spectrum antibiotics when narrow-spectrum options (penicillin/amoxicillin) are effective 1
• Do not prescribe courses shorter than 10 days (except azithromycin 5 days), as inadequate duration may lead to treatment failure and complications 7
• Never use aspirin in children with pharyngitis due to Reye syndrome risk 1, 7, 3

Special Populations

Recurrent Episodes

• Evaluate whether episodes represent true recurrent infections versus chronic carrier state with superimposed viral infections 1
• Chronic carriers with viral pharyngitis do not require antibiotic treatment 1

Infants Under 3 Months

• Maximum recommended dose is 30 mg/kg/day divided every 12 hours due to incompletely developed renal function 4
• At least 10 days of treatment is required to prevent acute rheumatic fever 4

Renal Impairment

• For GFR 10-30 mL/min: 500 mg or 250 mg every 12 hours 4
• For GFR <10 mL/min: 500 mg or 250 mg every 24 hours 4
• Patients on hemodialysis require an additional dose during and at the end of dialysis 4

Rationale for Treatment

• Early antibiotic treatment reduces symptom duration to less than 24 hours in most cases 5
• Treatment prevents acute rheumatic fever, suppurative complications (peritonsillar abscess, cervical lymphadenitis, mastoiditis), and reduces transmission to close contacts 2, 5
• Appropriate therapy shortens symptom duration by 1-2 days and decreases contagiousness 3
• Prevention of acute rheumatic fever remains the primary justification for antibiotic treatment, particularly in areas where it remains prevalent 2, 5