Duration of Antibiotic Therapy for Uncomplicated Impetigo
Topical Antibiotic Duration
For limited impetigo treated with topical antibiotics, the recommended duration is 5 days. 1, 2
- Topical mupirocin 2% ointment should be applied twice daily for 5 days 1
- Topical retapamulin 1% ointment should be applied twice daily for 5 days 1, 2
- The FDA-approved regimen for retapamulin specifically states a 5-day treatment course for impetigo covering up to 100 cm² in adults or 2% total body surface area in pediatric patients aged 9 months or older 2
Oral Antibiotic Duration
For extensive impetigo requiring oral antibiotics, the recommended duration is 7 days—not the shorter 5-day course used for topical agents. 1
- Cephalexin should be given for 7 days at 25-50 mg/kg/day divided into 4 doses for children, or 250-500 mg four times daily for adults 1
- Dicloxacillin should be given for 7 days at 25-50 mg/kg/day divided into 4 doses for children, or 250 mg four times daily for adults 1
- When MRSA is suspected, clindamycin should be given for 7 days at 20-30 mg/kg/day in 3 divided doses for children, or 300-450 mg three to four times daily for adults 1
- Sulfamethoxazole-trimethoprim (SMX-TMP) should be given for 7 days at 8-12 mg/kg/day (trimethoprim component) in 2 divided doses for children, or 1-2 double-strength tablets twice daily for adults 1
Critical Treatment Algorithm
The choice between 5-day topical therapy versus 7-day oral therapy depends on disease extent:
- Limited disease (few lesions, localized): Use topical mupirocin or retapamulin twice daily for 5 days 1
- Extensive disease (numerous lesions, widespread): Use oral antibiotics for 7 days 1
- Outbreaks: Use oral antibiotics for 7 days to decrease transmission 1
Common Pitfall to Avoid
Do not prescribe oral antibiotics for only 5 days—this is a treatment failure risk. The standard duration for oral antibiotic therapy is 7 days, which differs from the 5-day course used for topical agents 1. This distinction is critical because inadequate duration of oral therapy may lead to treatment failure and promote antibiotic resistance.
Special Considerations for Return to Activities
For athletes with impetigo, completion of 72 hours of antibiotic therapy is required before return to competition, along with no new skin lesions for 48 hours and no moist, exudative, or draining lesions 3. However, this return-to-play criterion does not change the total treatment duration, which remains 5 days for topical therapy or 7 days for oral therapy 1.