What is the appropriate evaluation and first‑line treatment for acute tonsillopharyngitis in an otherwise healthy child or adult?

Evaluation and First-Line Treatment of Acute Tonsillopharyngitis

Penicillin or amoxicillin for 10 days is the definitive first-line treatment for laboratory-confirmed Group A Streptococcal (GAS) pharyngitis in both children and adults, while patients with negative testing should receive only symptomatic care because the vast majority of acute tonsillopharyngitis is viral and self-limited. 1

Diagnostic Approach: When and How to Test

Clinical Features That Warrant Testing

Test only when bacterial features are present without viral signs: sudden-onset sore throat, fever, tonsillar exudates, tender anterior cervical lymphadenopathy, and absence of cough, rhinorrhea, hoarseness, or conjunctivitis. 1

• Do not test patients with clear viral features (cough, runny nose, hoarseness, conjunctivitis, oral ulcers) because these strongly indicate viral etiology and testing will only identify harmless carriers. 1

• Children under 3 years should not be tested unless an older sibling has confirmed GAS infection, because acute rheumatic fever and classic streptococcal pharyngitis are rare in this age group. 1

• Palatal petechiae, when present, are highly specific for streptococcal infection and substantially raise pre-test probability. 2

• In children, abdominal pain, nausea, or vomiting may accompany GAS pharyngitis, but these symptoms alone cannot diagnose strep throat without laboratory confirmation. 2, 3

Age-Specific Testing Algorithms

Children and adolescents (ages 5–15):

• Perform a rapid antigen detection test (RADT) first; a positive result (specificity ≥95%) confirms GAS and requires treatment. 1

• A negative RADT must be followed by a throat culture because RADT sensitivity is only 80–90%, missing 10–20% of true infections. 1

• The two-step approach is mandatory in children due to higher disease prevalence (20–30%) and meaningful risk of acute rheumatic fever. 1

Adults:

• A negative RADT alone is sufficient to rule out GAS; no backup throat culture is needed. 1

• This single-step approach is justified by low GAS prevalence (5–10%) and virtually zero risk of acute rheumatic fever in adults. 1

First-Line Antibiotic Therapy for Confirmed GAS

Penicillin or amoxicillin for a full 10 days is the only acceptable first-line regimen, offering narrow-spectrum activity, proven efficacy in preventing acute rheumatic fever, excellent safety, and low cost. 1

Specific Dosing Regimens

Penicillin V:

• Children <27 kg: 250 mg 2–3 times daily for 10 days 1
• Children ≥27 kg and adults: 500 mg 2–3 times daily for 10 days 1

Amoxicillin:

• 50 mg/kg once daily (maximum 1 g) for 10 days in all age groups 1
• Once-daily dosing improves compliance without sacrificing efficacy 1

Benzathine penicillin G (intramuscular, single dose):

• <27 kg: 600,000 units 1
• ≥27 kg: 1,200,000 units 1
• Reserved for patients with adherence concerns 1

Critical Treatment Principles

• The full 10-day course is essential to achieve maximal pharyngeal eradication and prevent acute rheumatic fever, even when symptoms improve within 3–4 days. 1

• Therapy initiated within 9 days of symptom onset still effectively prevents acute rheumatic fever, so waiting for culture results (even after a negative RADT in children) does not compromise outcomes. 1

• Shortening the course by even a few days markedly increases treatment-failure rates and rheumatic-fever risk. 1

Management of Penicillin-Allergic Patients

Non-anaphylactic (delayed) penicillin allergy:

• First-generation cephalosporins (cephalexin or cefadroxil) for 10 days are the preferred alternative. 1

• Avoid broad-spectrum cephalosporins (cefdinir, cefpodoxime, cefixime) because they are more expensive and promote resistance without added benefit. 1

Anaphylactic or immediate-type penicillin allergy:

• Clindamycin 20 mg/kg/day divided three times daily (maximum 1.8 g/day) for 10 days is the preferred beta-lactam-free option, with only ~1% resistance in the United States. 1

• Azithromycin 12 mg/kg once daily (maximum 500 mg) for 5 days is acceptable but faces 5–8% macrolide resistance rates. 1

• Clarithromycin 15 mg/kg/day divided twice daily for 10 days is another macrolide alternative. 1

Management When Testing Is Negative

Withhold antibiotics entirely and provide only symptomatic therapy because most negative-test cases are viral and self-limited. 1

Symptomatic Treatment

• Ibuprofen or acetaminophen for pain and fever relief are the only evidence-based pharmacologic therapies. 1, 4

• Avoid aspirin in children due to Reye syndrome risk. 1

• Corticosteroids are not recommended as adjunctive therapy; although they may reduce pain duration by approximately 5 hours, this minimal benefit does not justify routine use. 1

• Throat lozenges may provide comfort but represent a choking hazard in young children. 1

Common Pitfalls to Avoid

• Do not prescribe antibiotics based solely on clinical appearance (tonsillar exudates, white patches, pharyngeal erythema) because these findings occur in both viral and bacterial infections. 1, 4

• Do not test or treat asymptomatic household contacts; up to one-third may be asymptomatic GAS carriers, and prophylactic treatment does not reduce subsequent infection rates. 1

• Do not perform routine follow-up testing after completing therapy in asymptomatic patients; positive post-treatment tests often reflect carrier status rather than treatment failure. 1

• Do not order backup throat cultures in adults with a negative RADT; this wastes resources and offers no clinical benefit. 1, 4

• Recognize that recurrent pharyngitis may represent chronic GAS carriage with superimposed viral infections rather than repeated true GAS infections. 1

Special Considerations

• Up to 70% of patients with sore throat receive unnecessary antibiotic prescriptions, while only 20–30% of children and 5–10% of adults actually have GAS pharyngitis. 4, 5, 6

• Clinical scoring systems (Centor, McIsaac) predict a positive throat culture in ≤80% of cases and should not replace laboratory confirmation. 1, 7

• Most viral pharyngitis resolves within 3–7 days without treatment, and antibiotics shorten symptom duration by only 1–2 days even in confirmed GAS cases. 4, 5