Treatment of Tinea Pedis
For uncomplicated interdigital tinea pedis, apply topical terbinafine 1% cream twice daily for 1 week, which is superior to 4 weeks of clotrimazole and achieves mycological cure rates exceeding 90%. 1, 2, 3
First-Line Topical Treatment
Terbinafine 1% cream is the preferred topical agent due to its fungicidal action against the predominant causative organisms (T. rubrum and T. mentagrophytes), allowing for significantly shorter treatment duration compared to fungistatic azoles. 1, 2
Dosing by Location:
- Interdigital (between toes): Apply twice daily for 1 week 1, 4
- Plantar surface (bottom/sides of foot): Apply twice daily for 2 weeks 4
Alternative Topical Agents:
- 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—superior to clotrimazole but requires longer duration than terbinafine 1, 2
- Clotrimazole 1% cream: Apply twice daily for 4 weeks, but significantly less effective than terbinafine (73% vs 93.5% mycological cure) 1, 3
Oral Therapy for Severe or Resistant Disease
Reserve systemic antifungals for extensive disease, failed topical therapy, concomitant onychomycosis, or immunocompromised patients. 2, 5
First-Line Oral Agent:
- Terbinafine 250 mg once daily for 1-2 weeks provides similar mycological efficacy to 4 weeks of topical clotrimazole but with faster clinical resolution 1, 2
- Monitor for rare but serious adverse events including neutropenia and liver failure, particularly in patients with preexisting liver disease 1
Alternative Oral Agents:
- Itraconazole 100 mg daily for 2 weeks has similar efficacy to terbinafine but may have slightly higher relapse rates 1, 2
- Fluconazole is less effective than both terbinafine and itraconazole but may be useful when other agents are contraindicated due to fewer drug interactions 2
- Griseofulvin is not recommended as first-line therapy due to lower efficacy (57% cure rate) and longer treatment duration (4-8 weeks) 6, 7
Special Populations
For diabetic patients, prioritize terbinafine over itraconazole due to lower risk of drug interactions and hypoglycemia, as up to one-third of diabetics have onychomycosis which significantly predicts foot ulcer development. 2
For athletes requiring return to contact sports, provide minimum 72 hours of antifungal therapy before return, cover lesions with gas-permeable dressing followed by underwrap and stretch tape, and exclude from swimming pools until treatment initiated. 2
Prevention Strategies
Implement these measures to reduce recurrence rates from 8.5% to 2.1%: 1
- Apply foot powder after bathing 1, 2
- Thoroughly dry between toes after showering 1, 2
- Change socks daily 1, 2
- Periodically clean athletic footwear 1, 2
- Cover active foot lesions with socks before wearing underwear to prevent spread to groin (tinea cruris) 1, 2
Common Pitfalls to Avoid
Failing to treat all infected family members simultaneously results in reinfection, as transmission amongst family members is the most common route. 2, 5
Neglecting contaminated footwear as a source of reinfection leads to recurrence—address this by cleaning athletic shoes periodically. 2
Stopping treatment based on clinical improvement alone rather than mycological cure increases relapse risk—the definitive endpoint should be mycological cure, not just symptom resolution. 6
Examine the entire skin surface (hands, groin, body folds) when diagnosing tinea pedis, as dermatophyte infections commonly occur at multiple body sites simultaneously, with concomitant infections confirmed in 25% of cases. 2