Evaluation and Management of Pharyngitis
Use clinical scoring to guide testing, reserve antibiotics exclusively for confirmed Group A Streptococcus (GAS) pharyngitis, and provide symptomatic care for all other cases—most pharyngitis is viral and self-limited.
Initial Clinical Assessment
Apply the Modified Centor Criteria to stratify risk and guide testing decisions:
- Score 1 point each for: fever ≥38°C, absence of cough, tender anterior cervical adenopathy, tonsillar swelling/exudate 1
- Add 1 point for: age <15 years 1
- Subtract 1 point for: age ≥45 years 1
Key clinical features suggesting viral etiology (do NOT test for GAS):
- Presence of cough, rhinorrhea, hoarseness, or conjunctivitis 2, 3
- Oral ulcers 2, 3
- Cobblestoning of posterior pharynx 3
Important caveat: White patches and exudate can occur with viral infections and do NOT reliably distinguish bacterial from viral causes—laboratory confirmation is essential 4
Testing Strategy Based on Score
Score 0-1: No testing or antibiotics needed—viral etiology most likely 1
Score 2-3: Perform rapid antigen detection test (RADT) 1
- In children/adolescents: If RADT negative, obtain backup throat culture due to 80-90% sensitivity (misses 10-20% of true infections) 4, 2
- In adults: Negative RADT is sufficient to rule out GAS—no backup culture needed due to low prevalence (5-10%) and extremely low rheumatic fever risk 4, 5
Score ≥4: Either initiate antibiotics immediately OR perform RADT first 1
Critical pitfall: Do NOT test children under 3 years old unless an older sibling has confirmed GAS—this age group rarely develops GAS pharyngitis or rheumatic fever, and testing identifies asymptomatic carriers 4, 3
Antibiotic Treatment (Only for Confirmed GAS)
First-line therapy:
- Penicillin V for 10 days (narrow spectrum, no documented resistance, low cost) 1, 2
- Amoxicillin 50 mg/kg once daily (maximum 1 g) for 10 days—alternative with better compliance 4, 2
Penicillin-allergic patients (non-anaphylactic):
Penicillin-allergic patients (immediate hypersensitivity/anaphylaxis):
- Clindamycin 20 mg/kg/day divided in 3 doses (maximum 1.8 g/day) 4
- Azithromycin 12 mg/kg once daily (maximum 500 mg) 4
Treatment duration must be 10 days to prevent acute rheumatic fever—shorter courses (3-5 days) are insufficient despite better compliance 1, 6
Key benefit: Antibiotics shorten symptom duration by only 1-2 days but prevent suppurative complications and rheumatic fever when initiated within 9 days of symptom onset 1, 4, 6
Symptomatic Management (For ALL Patients)
Provide regardless of etiology:
- Ibuprofen or acetaminophen for pain and fever relief 4, 2, 3
- Throat lozenges for comfort 4
- Reassurance that viral symptoms typically resolve in <1 week 4
Avoid aspirin in children due to Reye syndrome risk 3
Common Pitfalls to Avoid
Do NOT prescribe antibiotics based on clinical appearance alone—even with a Centor score of 4, only 40-60% actually have GAS in pediatric populations 4
Do NOT treat or test asymptomatic household contacts—up to one-third are asymptomatic carriers, and prophylaxis does not reduce subsequent infection rates 4
Do NOT obtain follow-up cultures after completing treatment in asymptomatic patients—positive tests cannot distinguish active infection from carrier state 4
Do NOT switch antibiotics without microbiological indication—this increases adverse effects without clinical benefit 4
Special Populations
Children under 3 years: Do not test or treat unless older sibling has confirmed GAS 4, 3
Patients with mononucleosis features (generalized lymphadenopathy, splenomegaly): Consider Epstein-Barr virus testing 2
High rheumatic fever risk populations (developing countries, certain regions of Australia): Lower threshold for treatment, but still require laboratory confirmation when feasible 1
When to Reconsider Diagnosis
If symptoms persist beyond 3-4 days or worsen significantly, consider: