What are the typical symptoms and treatment options for a patient with a Group A Streptococcus (GAS) infection?

Group A Streptococcus (GAS) Infection: Symptoms and Treatment

Clinical Presentation

GAS pharyngitis presents with distinct symptom patterns that vary significantly by age group, and recognizing these differences is critical for accurate diagnosis.

Classic Presentation in School-Age Children and Adults

• Acute onset of throat pain with fever, headache, abdominal pain, and dysphagia 1, 2
• Physical examination findings include intense tonsillopharyngeal erythema, yellow tonsillar exudate, and tender/enlarged anterior cervical lymphadenopathy 2, 3
• Important caveat: Only 20-30% of patients present with this classic constellation of symptoms 2

Atypical Presentation in Young Children (<3 Years)

• Fever with mucopurulent rhinitis, excoriated nares, and diffuse adenopathy 1
• Exudative pharyngitis is rare in this age group 1
• Testing is generally not recommended for children <3 years because acute rheumatic fever (ARF) is extremely rare (only 5% of ARF cases occur in children <5 years, with median age of 4 years) 1, 3

Key Distinguishing Features from Viral Pharyngitis

• Absence of viral symptoms such as cough, rhinorrhea, conjunctivitis, or hoarseness strongly suggests bacterial rather than viral etiology 3
• Bilateral tender cervical lymphadenopathy rather than generalized adenopathy 3

Diagnostic Approach

Microbiological confirmation is essential before treatment in most cases, as clinical diagnosis alone leads to massive antibiotic overprescribing.

When to Test

• Test patients with sore throat who lack viral symptoms (cough, rhinorrhea) 1, 3
• Do NOT test patients with clear viral symptoms, children <3 years old, or asymptomatic household contacts 1, 3

Testing Strategy

• Rapid Antigen Detection Test (RADT) is acceptable as the sole diagnostic test in adults due to high specificity, allowing negative results to exclude diagnosis without backup culture 1
• Backup throat culture for negative RADT results is recommended in children to maximize sensitivity 1
• Follow-up testing after treatment is NOT routinely recommended unless the patient is at high risk for ARF or has recurrent symptoms 1

Treatment Recommendations

First-Line Antibiotic Therapy

Penicillin or amoxicillin remains the definitive treatment of choice based on proven efficacy, narrow spectrum, safety, and low cost—no penicillin-resistant GAS has ever been documented. 1, 3

Dosing Regimens

• Penicillin V: 250 mg four times daily or 500 mg twice daily for 10 days in adults 1, 4
• Amoxicillin: 50 mg/kg once daily (maximum 1000 mg) or 25 mg/kg twice daily (maximum 500 mg/dose) for 10 days 1
• Benzathine penicillin G (intramuscular): 600,000 units for patients <27 kg; 1,200,000 units for patients ≥27 kg as a single dose 1

Penicillin-Allergic Patients

Non-Immediate Hypersensitivity

• First-generation cephalosporins (cephalexin 500 mg every 6 hours orally for 10 days) with cross-reactivity risk <3-10% 1, 5

Immediate/Anaphylactic Hypersensitivity

• Clindamycin: 20-30 mg/kg/day in 3 doses (maximum 300 mg/dose) for 10 days 1, 5
• Macrolides (azithromycin, clarithromycin) are acceptable alternatives but have higher resistance rates 5

Critical Treatment Duration

A full 10-day course is mandatory to achieve maximal pharyngeal eradication and prevent ARF, regardless of clinical improvement 1, 4

Adjunctive Symptomatic Management

Recommended Analgesics

• NSAIDs (ibuprofen) or acetaminophen for fever and pain relief 1, 6
• Avoid aspirin in children due to Reye syndrome risk 1, 6

Corticosteroids: Not Recommended

Corticosteroids should NOT be used as adjunctive therapy—they provide only minimal symptom reduction (approximately 5 hours) and do not prevent complications like ARF. 1, 6

Treatment Outcomes and Goals

Primary Objectives (in Order of Priority)

1. Prevention of acute rheumatic fever (the most critical outcome) 1
2. Prevention of suppurative complications (peritonsillar abscess, cervical lymphadenitis, mastoiditis) 1, 2
3. Symptom improvement within 24-48 hours of therapy 1
4. Reduction of contagion to allow rapid return to normal activities 1, 2

Expected Clinical Course

• Fever and symptoms typically resolve within a few days even without treatment 1
• Clinical response to antibiotics should occur within 24-48 hours 1
• Persistence of symptoms beyond this period suggests either suppurative complications or chronic GAS carriage with intercurrent viral infection 1

Critical Pitfalls to Avoid

Diagnostic Errors

• Do not treat based on clinical symptoms alone—this results in treating 56-75% of patients with non-streptococcal pharyngitis unnecessarily 1
• Do not test asymptomatic household contacts—up to 20% may be chronic carriers, and prophylactic treatment is not beneficial 1

Treatment Errors

• Do not use tetracyclines, sulfonamides, or trimethoprim-sulfamethoxazole—high resistance rates and lack of efficacy 5
• Do not prescribe broad-spectrum antibiotics—this is a common error contributing to antibiotic resistance 1
• Do not discontinue antibiotics early even if symptoms improve—incomplete courses fail to eradicate GAS and prevent ARF 4

Special Populations

• Chronic GAS carriers (persistent positive cultures without rising antibody titers) do not require treatment unless special circumstances exist (ARF outbreak, family history of ARF, excessive family anxiety) 1
• Recurrent episodes within months may represent chronic carriage with intercurrent viral infections rather than true recurrent GAS pharyngitis 1