Treatment of Tinea Pedis
For interdigital tinea pedis, apply topical terbinafine 1% cream twice daily for 1 week, which provides superior efficacy compared to longer courses of other topical antifungals. 1, 2
First-Line Topical Therapy
Terbinafine 1% cream is the preferred first-line treatment due to its fungicidal mechanism and shorter treatment duration:
- For interdigital tinea pedis (between the toes): Apply twice daily for 1 week 1, 2
- For plantar tinea pedis (bottom or sides of foot): Apply twice daily for 2 weeks 2
- Terbinafine achieves 93.5% mycological cure rates at 4 weeks and 89.7% effective treatment rates, significantly superior to clotrimazole's 73.1% and 58.7% respectively 3
- The fungicidal action allows for dramatically shorter treatment courses compared to fungistatic agents 4, 5
Alternative Topical Agents
If terbinafine is unavailable or contraindicated:
- Ciclopirox olamine 0.77% cream/gel: Apply twice daily for 4 weeks, achieving 60% cure at treatment end and 85% cure two weeks post-treatment 1, 6
- Clotrimazole 1% cream: Apply twice daily for 4 weeks, though less effective than terbinafine 1, 3
- Other options include azoles, benzylamine, tolnaftate, and amorolfine applied once to twice daily for 1-6 weeks 7
Oral Therapy for Severe or Resistant Cases
Reserve systemic treatment for extensive disease, failed topical therapy, concomitant onychomycosis, or immunocompromised patients 6, 7:
- Oral terbinafine 250 mg once daily for 1 week: Provides similar mycological efficacy to 4 weeks of topical clotrimazole but with faster clinical resolution 1, 8
- Oral itraconazole 100 mg daily for 2 weeks: Similar efficacy to terbinafine but may have slightly higher relapse rates 1, 6
- Monitor for rare but serious adverse events with oral terbinafine, including neutropenia and liver failure, particularly in patients with preexisting liver disease 1, 8
Prevention Strategies
Implement these measures to reduce recurrence from 8.5% to 2.1%:
- Apply foot powder after bathing 1, 6
- Thoroughly dry between toes after showering 1, 8
- Change socks daily 1, 8
- Periodically clean athletic footwear 1, 6
- Cover active foot lesions with socks before wearing underwear to prevent spread to groin (tinea cruris) 6, 8
Risk Factors to Address
Identify and manage these predisposing conditions:
- Swimming and running (especially marathon runners, with infection rates up to 22%) 1, 8
- Warm, humid environments 1, 8
- Male gender 1, 8
- Obesity and diabetes 1, 8
Common Pitfalls to Avoid
- Failing to treat all infected family members simultaneously results in reinfection 6, 8
- Neglecting contaminated footwear as a source of reinfection leads to recurrence 6
- Stopping treatment based on clinical improvement alone rather than mycological cure increases relapse risk 6, 8
- Not examining other body sites (hands, groin, body folds) when diagnosing tinea pedis, as 25% of cases have concomitant infections at other locations 6
Treatment Endpoint
The definitive endpoint should be mycological cure (negative microscopy and culture), not just clinical response 6, 8. Continue treatment for at least one week after clinical clearing of infection 9. Consider follow-up with repeat mycology sampling at the end of the standard treatment period 8.