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

Treatment of Athlete's Foot (Tinea Pedis)

For interdigital athlete's foot, apply topical terbinafine 1% cream twice daily for 1 week—this is the most effective first-line treatment with superior efficacy and shorter duration than other topical agents. 1, 2, 3

First-Line Topical Therapy

Terbinafine (Preferred)

• Terbinafine 1% cream applied twice daily for 1 week for interdigital (between-toes) tinea pedis achieves 66-89% cure rates and is more effective than longer courses of other antifungals 1, 2, 4
• For infection on the bottom or sides of the foot, extend terbinafine to twice daily for 2 weeks 3
• Wash affected skin with soap and water and dry completely before applying 3
• Wear well-fitting, ventilated shoes and change shoes and socks at least once daily 3

Alternative Topical Agents (When Terbinafine Unavailable)

• Ciclopirox olamine 0.77% cream/gel twice daily for 4 weeks achieves approximately 60% cure at end of treatment and 85% cure two weeks post-treatment, superior to clotrimazole 1, 2, 5
• Clotrimazole 1% cream twice daily for 4 weeks is less effective than terbinafine but widely available over-the-counter 1, 6

Oral Therapy for Severe or Resistant Cases

Reserve oral antifungals for severe disease, failed topical therapy, concomitant onychomycosis, or immunocompromised patients. 1, 2, 7

First-Line Oral Option

• 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
• Has fungicidal action allowing shorter treatment duration 1
• Over 70% oral absorption unaffected by food intake 1
• Monitor for rare but serious adverse events including isolated neutropenia and hepatic failure, especially in patients with pre-existing liver disease 1
• Obtain baseline liver function tests (LFTs) and complete blood count (CBC) before initiating oral terbinafine in adults with history of hepatotoxicity or hematologic abnormalities 1

Alternative Oral Options

• Itraconazole 100 mg daily for 2 weeks has similar mycological efficacy to terbinafine but slightly higher relapse rates 1, 2
• Pulse dosing of itraconazole 200-400 mg per day for 1 week per month is an alternative 1
• Itraconazole offers broader antifungal spectrum than terbinafine, covering Candida species and non-dermatophyte moulds, advantageous for mixed infections 1
• Fluconazole is less effective than itraconazole or terbinafine for dermatophyte infections but may be useful when other agents are contraindicated due to fewer drug interactions 1

Critical Prevention Measures to Prevent Recurrence

Footwear Decontamination (Often Overlooked)

• Failing to address contaminated footwear is a major source of recurrence—shoes harbor large numbers of viable dermatophyte spores 1, 2
• If shoes cannot be discarded, place naphthalene mothballs in shoes and seal in a plastic bag for minimum 3 days, then air out to markedly lower fungal load 1
• Periodically spray terbinafine solution inside shoes for additional antifungal protection 1
• Apply antifungal powders containing miconazole, clotrimazole, or tolnaftate inside shoes 1

Daily Hygiene Practices

• Thoroughly dry between toes after showering—this is essential to reduce recurrence risk 1, 2
• Change to cotton, absorbent socks daily—this reduces infection incidence from approximately 8.5% to 2.1% 1
• Apply antifungal foot powder after bathing to further reduce infection rates 1, 2
• Clean athletic footwear periodically 1, 2

Household Transmission Prevention

• Treat all infected family members simultaneously to prevent reinfection cycles 1, 2
• Cover active foot lesions with socks before wearing underwear to prevent spread to groin area 1, 2
• Avoid sharing toenail clippers with family members 1
• Wear protective footwear in public bathing facilities, gyms, and hotel rooms 1

Common Pitfalls to Avoid

Concomitant Onychomycosis (Nail Infection)

• Failing to examine for concomitant onychomycosis is a critical error—nail infection requires extended oral terbinafine therapy (approximately 12-16 weeks) and acts as a reservoir for foot reinfection 1
• When dermatophyte skin infection co-exists with nail infection, oral antifungal treatment is indicated because the nail serves as a reinfection source 1

Treatment Endpoint

• The definitive endpoint for adequate treatment should be mycological cure, not just clinical response 2
• Consider follow-up with repeat mycology sampling at the end of the standard treatment period 2

Special Populations

• For diabetic patients, prefer terbinafine over itraconazole due to lower risk of drug interactions and hypoglycemia 1
• Up to one-third of diabetics have onychomycosis, which significantly predicts foot ulcer development 1
• Athletes require minimum 72 hours of topical or systemic antifungal therapy before return to contact sports, with lesions covered with gas-permeable dressing 1

Risk Factors for Tinea Pedis

• Swimming, running, warm humid environments 1, 2
• Male gender, obesity, and diabetes 1, 2
• The causative organisms are predominantly T. rubrum and T. mentagrophytes 1, 7