What is the treatment for strep throat vs tonsillitis?

Treatment of Strep Throat vs Tonsillitis

The key distinction is that strep throat (Group A Streptococcal pharyngitis) requires antibiotic treatment with penicillin or amoxicillin for 10 days, while viral tonsillitis requires only supportive care—making accurate diagnosis through rapid antigen detection testing or throat culture essential before initiating antibiotics. 1, 2

Diagnostic Approach: The Critical First Step

Testing is mandatory before prescribing antibiotics. The most common pitfall is treating presumed bacterial infection without confirmation, leading to unnecessary antibiotic use in the 60% of adults who receive antibiotics despite only 10% actually having streptococcal infection 1, 3.

Clinical Features Suggesting Bacterial (Strep) Infection:

• Sudden onset of sore throat with fever >38°C 2, 4
• Tonsillar exudates 2, 5
• Tender anterior cervical lymphadenopathy 2, 5
• Absence of cough (cough suggests viral etiology) 5, 4, 6

Clinical Features Suggesting Viral Tonsillitis:

• Absence of high fever, tonsillar exudate, and cervical lymphadenopathy 2
• Presence of cough, coryza, conjunctivitis, or diarrhea 6

Testing Algorithm:

• Use modified Centor criteria to assess likelihood of streptococcal infection 5
• Patients with 3-4 Centor criteria should undergo rapid antigen detection testing (RADT) and/or throat culture 1, 5
• Patients with fewer than 3 Centor criteria do not need testing or antibiotics 5
• In children and adolescents, perform throat culture after negative RADT to confirm the result 3

Treatment for Confirmed Strep Throat (Group A Streptococcal Pharyngitis)

First-Line Antibiotic Treatment:

Penicillin V remains the gold standard due to proven efficacy, narrow spectrum, safety, and low cost 1, 5, 6:

• Penicillin V for 10 days (standard dosing) 2, 5
• Amoxicillin 50 mg/kg once daily (maximum 1000 mg) for 10 days is equally effective and often preferred in children due to better palatability and once-daily dosing 2, 5

The full 10-day course is critical—shorter courses result in higher bacteriologic failure rates and increased risk of complications 2, 4, 7. Penicillin failure rates have increased from 2-10% historically to approximately 30%, primarily due to non-compliance with the 10-day regimen 7.

For Penicillin-Allergic Patients:

Non-anaphylactic allergy:

• First-generation cephalosporins (cephalexin, cefadroxil) for 10 days 2, 5, 3

Anaphylactic allergy:

• Clindamycin 7 mg/kg three times daily (maximum 300 mg per dose) for 10 days 2, 5
• Azithromycin 12 mg/kg once daily (maximum 500 mg) for 5 days 5, 8
• Clarithromycin 7.5 mg/kg twice daily (maximum 250 mg per dose) for 10 days 5

Important caveat: Significant macrolide resistance exists in some U.S. regions, making azithromycin and clarithromycin less reliable 5, 3. Consider local resistance patterns when selecting these alternatives.

Clinical Benefits of Antibiotic Treatment:

Antibiotics provide modest symptomatic benefit—shortening sore throat duration by only 1-2 days with a number needed to treat of 6 at 3 days and 21 at 1 week 1. The primary justification for treatment is preventing complications:

• Suppurative complications (peritonsillar abscess, acute otitis media) 1, 5
• Acute rheumatic fever (particularly important in children and adolescents) 1, 6
• Limiting spread to close contacts 1

Antibiotics do not prevent post-streptococcal glomerulonephritis 1.

Treatment for Viral Tonsillitis

No antibiotics are indicated for viral tonsillitis. 1, 5, 4

Supportive Care:

• Acetaminophen or NSAIDs (aspirin, ibuprofen) for pain and fever 1, 5
• Throat lozenges for symptomatic relief 1
• Salt water gargles (though limited data support this) 1
• Reassurance that symptoms typically resolve within 1 week 1

Corticosteroids are not routinely recommended despite some consideration in severe cases with 3-4 Centor criteria 5.

Management of Treatment Failures and Recurrent Infections

If Symptoms Persist or Worsen After 5 Days of Appropriate Antibiotics:

Consider alternative regimens for documented recurrent GAS tonsillitis: 2, 4

• Clindamycin 20-30 mg/kg/day in 3 doses (maximum 300 mg/dose) for 10 days 2
• Amoxicillin-clavulanate 40 mg amoxicillin/kg/day in 3 doses (maximum 2000 mg amoxicillin/day) for 10 days 2, 4
• Penicillin V with rifampin: Penicillin V 50 mg/kg/day in 4 doses for 10 days plus rifampin 20 mg/kg/day in 1 dose for the last 4 days 2

Tonsillectomy Considerations:

Tonsillectomy is rarely indicated and should only be considered after meeting Paradise criteria: 7 episodes in 1 year, 5 episodes in each of the past 2 years, or 3 episodes in each of the past 3 years 2, 4, 3. Tonsillectomy is not recommended solely to reduce frequency of streptococcal pharyngitis 1, 2.

Critical Pitfalls to Avoid

• Never prescribe antibiotics without confirming GAS infection through testing 5, 4—this is the single most important error to avoid
• Never use broad-spectrum antibiotics when narrow-spectrum penicillins are effective 5, 4
• Never prescribe courses shorter than 10 days (except azithromycin 5-day course) as this increases treatment failure 2, 4, 7
• Never obtain routine follow-up throat cultures in asymptomatic patients who completed appropriate therapy 2, 5, 4
• Never treat asymptomatic GAS carriers with antibiotics 1, 5, 4

Severe Cases Requiring Urgent Evaluation:

Patients with difficulty swallowing, drooling, neck tenderness, or significant swelling require immediate evaluation for peritonsillar abscess, parapharyngeal abscess, epiglottitis, or Lemierre syndrome 4.