What to do about persistent fevers after completing a 10-day course of penicillin (penicillin) for group A streptococcal (GABHS) tonsillitis, despite feeling well and having no pain?

Ongoing Fevers After Completing Penicillin for Group A Strep Tonsillitis

Discontinue antibiotics and provide supportive care only—this patient is most likely a chronic GAS carrier experiencing an intercurrent viral infection, not treatment failure. 1

Understanding the Clinical Scenario

The combination of persistent fever with feeling well, no pain, and normal energy strongly suggests a viral upper respiratory infection superimposed on chronic streptococcal carriage rather than true penicillin treatment failure. 1

Key distinguishing features:

• Chronic carriers (up to 20% of school-aged children during winter/spring) can harbor streptococci in their pharynx while experiencing new viral infections that produce fever and other symptoms 1
• True treatment failure with penicillin is actually rare despite bacteriologic failure rates of 20-30%, because many "failures" represent carrier states 2, 3
• Carriers are at very low risk for complications including rheumatic fever and are unlikely to spread infection 1

Recommended Management Approach

Immediate action:

• Stop antibiotics—continuing them for what is likely viral provides no benefit and increases adverse effects and resistance 1
• Provide symptomatic relief with ibuprofen or acetaminophen for fever (avoid aspirin due to Reye syndrome risk) 1
• Offer supportive care for viral upper respiratory symptoms 1

When to Consider Alternative Antibiotic Therapy

Only consider retreatment if: 4

• Symptoms clearly worsen after initial improvement
• Fever and pharyngeal symptoms persist beyond 10 days without any improvement
• The patient develops severe symptoms (significant pain, difficulty swallowing, systemic toxicity)

If retreatment is truly necessary:

• Obtain throat culture or rapid antigen test immediately to confirm persistent GAS 4
• If culture remains positive after 10 days of penicillin, this represents true treatment failure requiring a different approach 4
• Clindamycin 300 mg three times daily for 10 days is the preferred treatment for penicillin failure in adults, with approximately 1% resistance rates and superior eradication even in chronic carriers 4, 5
• Amoxicillin-clavulanate 875 mg twice daily for 10 days is an effective alternative that addresses beta-lactamase-producing co-pathogens 4

Understanding Penicillin "Failure" Rates

While bacteriologic failure rates have increased from 2-10% historically to approximately 30% currently, this does not mean clinical failure. 2, 3 Multiple factors contribute:

• Non-compliance with 10-day regimen (most common) 3
• Chronic carrier state with intercurrent viral infection 1
• Beta-lactamase-producing co-pathogens protecting streptococci 3, 6
• Reinfection from family members or peers 3

Critical Pitfalls to Avoid

Do not:

• Simply repeat another 10-day course of penicillin—this has high failure rates and delays appropriate management 4
• Obtain routine follow-up throat cultures in asymptomatic patients who completed therapy 4
• Use macrolides (azithromycin, clarithromycin) as first-line alternatives for suspected treatment failure due to 5-8% resistance rates in the United States 4
• Continue antibiotics based solely on persistent fever when the patient otherwise feels well 1

Remember: The primary goals of treating strep throat are preventing acute rheumatic fever and suppurative complications, not eradicating carrier states. 7 Carriers who feel well do not require treatment regardless of positive cultures. 1