Pharyngitis Treatment
For acute pharyngitis, test patients with ≥3 modified Centor criteria using rapid antigen detection test (RADT) and treat confirmed Group A Streptococcus (GAS) with penicillin or amoxicillin for 10 days; do not prescribe antibiotics for viral pharyngitis or empirically without testing. 1
Diagnostic Approach
Use the modified Centor criteria to stratify patients and determine who needs testing 2:
- Fever by history
- Tonsillar exudates
- Tender anterior cervical adenopathy
- Absence of cough
Testing algorithm:
- <3 Centor criteria: No testing needed—viral etiology most likely 2, 1
- ≥3 Centor criteria: Perform RADT 2, 1
- Positive RADT: Treat with antibiotics (no backup culture needed due to high specificity) 1
- Negative RADT in children/adolescents: Backup throat culture required 1
- Negative RADT in adults: No backup culture needed (low incidence of GAS and minimal rheumatic fever risk) 1
Do not test if obvious viral features present: cough, rhinorrhea, hoarseness, oral ulcers 1
Antibiotic Treatment for Confirmed GAS
First-Line Therapy (Non-Penicillin Allergic)
Penicillin or amoxicillin are the drugs of choice based on narrow spectrum, low adverse effects, and low cost 1:
- Penicillin V: 250 mg 4 times daily (adults) or 500 mg twice daily for 10 days 1
- Amoxicillin: 500 mg twice daily or 1000 mg once daily for 10 days 1
- Benzathine penicillin G IM: Single dose (1.2 million units for ≥27 kg) if adherence concerns 1
Penicillin-Allergic Patients
For non-anaphylactic penicillin allergy 1:
- First-generation cephalosporins (cephalexin 500 mg twice daily or cefadroxil 1 g once daily) for 10 days 1
For anaphylactic penicillin allergy 1:
- Clindamycin: 300 mg three times daily for 10 days 1
- Clarithromycin: 250 mg twice daily for 10 days 1
- Azithromycin: 500 mg once daily for 5 days 1
Critical caveat: Azithromycin shows inferior bacterial eradication, higher recurrence rates, and increased adverse events compared to penicillin 3. Geographic resistance to macrolides varies significantly 4. Reserve macrolides only for true penicillin-allergic patients.
Symptomatic Management
Analgesics/antipyretics are recommended adjuncts 1:
- Acetaminophen or NSAIDs for moderate-to-severe symptoms
- Throat lozenges
- Avoid aspirin in children (Reye syndrome risk) 1
Corticosteroids are not recommended 1
What NOT to Do
- Do not prescribe amoxicillin-clavulanate as initial therapy—unnecessary broad spectrum 5, 6
- Do not treat asymptomatic household contacts 1
- Do not perform post-treatment cultures routinely 1
- Do not treat GAS carriers (asymptomatic with positive test)—they don't spread infection or develop complications 1
- Do not prescribe antibiotics empirically without testing—over 60% of adults with sore throat receive unnecessary antibiotics despite most cases being viral 2
Clinical Benefits of Antibiotics
Antibiotics for confirmed GAS provide 2:
- Symptom reduction by 1-2 days (modest benefit; NNT = 6 at 3 days)
- Prevention of acute rheumatic fever (more relevant in children/adolescents)
- Prevention of suppurative complications (peritonsillar abscess)
- Reduced transmission
Important limitation: Antibiotics do not prevent post-streptococcal glomerulonephritis 2
Red Flags Requiring Urgent Evaluation
Evaluate immediately for serious complications if patient presents with 2:
- Difficulty swallowing or drooling
- Neck tenderness or swelling
- Severe unilateral throat pain (peritonsillar abscess)
- Persistent high fever with severe pharyngitis in adolescents/young adults (consider Lemierre syndrome from Fusobacterium necrophorum)
Special Populations
Children <3 years old: Generally do not test—GAS pharyngitis and rheumatic fever are uncommon in this age group 1
Recurrent pharyngitis: Consider that patient may be a chronic GAS carrier experiencing repeated viral infections rather than true recurrent streptococcal infections 1