What is the recommended treatment for athlete's foot (tinea pedis)?

Treatment of Athlete's Foot (Tinea Pedis)

Apply topical terbinafine 1% cream twice daily for 1 week for interdigital tinea pedis, or twice daily for 2 weeks for infection on the bottom or sides of the foot. 1, 2

First-Line Topical Therapy

• Terbinafine 1% cream is the most effective topical agent, achieving 66-89% cure rates with significantly shorter treatment duration than other antifungals due to its fungicidal (not just fungistatic) mechanism. 1, 3, 4, 5, 6

• For interdigital tinea pedis (between the toes): Apply terbinafine 1% cream twice daily for 1 week. 1, 3, 2

• For infection on the bottom or sides of the foot: Apply terbinafine 1% cream twice daily for 2 weeks. 2

• Ciclopirox olamine 0.77% cream/gel is an effective alternative when terbinafine is unavailable, applied twice daily for 4 weeks, achieving 60% cure at end of treatment and 85% cure two weeks post-treatment. 1, 3

• Clotrimazole 1% cream is less effective than terbinafine but widely available over-the-counter, requiring twice-daily application for 4 weeks. 1, 3

When to Use Oral Antifungal Therapy

Reserve oral therapy for severe disease, failed topical treatment, concomitant nail infection (onychomycosis), or immunocompromised patients. 1, 3, 7

Oral Treatment Options

• Terbinafine 250 mg once daily for 1-2 weeks is the first-line oral agent, providing faster clinical resolution than topical therapy and superior efficacy against dermatophytes. 1, 3

• Itraconazole 100 mg daily for 2 weeks offers comparable efficacy to oral terbinafine but has a slightly higher relapse rate and broader antifungal spectrum (covers Candida and non-dermatophyte molds). 1, 3

• Fluconazole is less effective than both terbinafine and itraconazole for dermatophyte infections but may be useful when other agents are contraindicated due to fewer drug interactions. 1

• Griseofulvin is not recommended as first-line therapy due to lower efficacy (30-57% cure rates) and longer treatment duration. 1, 3

Critical Prevention Measures to Prevent Recurrence

Failure to address these factors is the most common cause of treatment failure and recurrence:

• Treat all infected family members simultaneously to prevent reinfection cycles. 1, 3

• Examine for and treat concomitant onychomycosis (nail infection), which requires 12-16 weeks of oral terbinafine and serves as a reservoir for reinfection. 1

• Decontaminate or discard contaminated footwear, as shoes harbor large numbers of viable fungal spores. 1, 3

  • If shoes cannot be discarded, place naphthalene mothballs in shoes, seal in a plastic bag for minimum 3 days, then air out. 1
  • Alternatively, spray terbinafine solution inside shoes periodically. 1

• Apply antifungal foot powder after bathing, which reduces infection rates from 8.5% to 2.1%. 1, 3

• Change to cotton, absorbent socks daily and thoroughly dry between toes after showering. 1, 3

• Cover active foot lesions with socks before wearing underwear to prevent spread to the groin area. 1, 3

• Wear protective footwear in public bathing facilities, gyms, and hotel rooms. 1

Safety Monitoring for Oral Terbinafine

• Baseline liver function tests (LFTs) and complete blood count (CBC) are recommended before initiating oral terbinafine in adults with history of hepatotoxicity or hematologic abnormalities. 1

• Monitor for rare but serious adverse events including isolated neutropenia and hepatic failure, particularly in patients with pre-existing liver disease. 1, 3

• Common adverse effects include headache, taste disturbance, and gastrointestinal upset. 1

Special Populations

• Diabetic patients: Prefer terbinafine over itraconazole due to lower risk of drug interactions and hypoglycemia. 1

• Athletes: Require minimum 72 hours of antifungal therapy before return to contact sports, with lesions covered with gas-permeable dressing. 1

• Children under 12 years: Consult a physician before using topical terbinafine. 2

Common Pitfalls to Avoid

• Treating only clinical symptoms without confirming mycological cure leads to recurrence; consider follow-up mycology sampling at end of treatment. 3

• Not examining the entire skin surface (hands, groin, body folds) for secondary infection sites, as dermatophytes spread to multiple body locations in 25% of cases. 1

• Failing to address environmental sources (contaminated footwear, shared nail clippers) causes reinfection. 1