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

Treatment of Athlete's Foot (Tinea Pedis)

For most cases of athlete's foot, apply topical terbinafine 1% cream twice daily for 1 week for interdigital (between-toes) disease, or 2 weeks for plantar (bottom/sides of foot) involvement. 1, 2, 3

First-Line Topical Treatment

Terbinafine 1% cream is the gold standard topical agent, recommended by the American Academy of Pediatrics as first-line therapy due to superior efficacy with the shortest treatment duration compared to all other topical antifungals. 1, 2

Application Protocol:

• Interdigital disease (between toes): Apply twice daily for 1 week 1, 2, 3
• Plantar disease (bottom or sides of foot): Apply twice daily for 2 weeks 2, 3
• Wash affected skin with soap and water and dry completely before applying 3
• Terbinafine achieves 66-93.5% mycological cure rates, significantly superior to clotrimazole's 73.1% cure rate 4, 5

Alternative Topical Agents (if terbinafine unavailable):

• 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, 4, 2
• Clotrimazole 1% cream: Apply twice daily for 4 weeks—less effective than terbinafine but widely available over-the-counter 1, 2

Oral Therapy for Severe or Resistant Cases

Reserve oral antifungals for extensive disease, failed topical therapy, concomitant nail involvement (onychomycosis), or immunocompromised patients. 1, 4, 2

First-Line Oral Agent:

• Terbinafine 250 mg once daily for 1-2 weeks is the most effective oral treatment, with fungicidal action allowing shorter treatment duration and faster clinical resolution than topical treatments 1, 4, 2
• Over 70% oral absorption unaffected by food intake 1
• Superior efficacy against dermatophytes with lower minimum inhibitory concentration (MIC) than itraconazole 1

Alternative Oral Agents:

• Itraconazole 100 mg daily for 2 weeks has similar mycological efficacy to terbinafine but may have slightly higher relapse rates 1, 4, 2
• Pulse dosing option: 200-400 mg daily for 1 week per month 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 1
• Griseofulvin is NOT recommended as first-line therapy due to lower efficacy (30-40% cure rates) and longer treatment duration 1

Essential Adjunctive Measures (Critical for Prevention of Recurrence)

These prevention strategies must be implemented alongside pharmacologic treatment to reduce recurrence rates:

• Apply foot powder after bathing to reduce tinea pedis rates from 8.5% to 2.1% 1
• Thoroughly dry between toes after showering 1, 4
• Change socks daily and wear cotton, absorbent socks 1, 4
• Clean athletic footwear periodically or discard old, moldy footwear 1, 4
• Treat contaminated footwear: Place naphthalene mothballs in shoes and seal in plastic bag for minimum 3 days, or spray terbinafine solution into shoes periodically 1
• Cover active foot lesions with socks before wearing underwear to prevent spread to groin area (tinea cruris) 1, 4, 2
• Treat all infected family members simultaneously to prevent reinfection 1, 4, 2
• Wear protective footwear in public bathing facilities, gyms, and hotel rooms 1

Special Populations and Considerations

Athletes:

• Require minimum 72 hours of antifungal therapy before return to contact sports 1, 2
• Cover lesions with gas-permeable dressing followed by underwrap and stretch tape 1
• Exclude from swimming pools and discourage barefoot walking in locker rooms until treatment initiated 1
• Athletes have documented infection rates up to 22%, particularly swimmers and marathon runners 2

Diabetic Patients:

• Terbinafine is preferred 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

Pediatric Patients:

• Same topical terbinafine regimen for children 12 years and older 3
• For children under 12 years: consult physician for weight-based dosing of oral terbinafine 2

Common Pitfalls to Avoid

• Do not assume treatment failure is drug resistance alone—poor compliance, inadequate drug penetration, bacterial superinfection, or reinfection from nails/footwear are more common causes 2
• Always examine for concomitant onychomycosis (present in 25% of cases), which requires longer treatment and serves as a reservoir for reinfection 1, 2
• Examine entire skin surface including hands, groin, and body folds, as dermatophyte infections commonly occur at multiple body sites simultaneously 1
• Failing to address contaminated footwear as a source of reinfection leads to recurrence 1, 4
• Not treating all infected family members simultaneously results in reinfection 1, 4

Monitoring and Follow-Up

• Monitor liver function tests at baseline and during prolonged oral therapy, especially with itraconazole 2
• Monitor for rare but serious adverse events with oral terbinafine, including neutropenia and liver failure, particularly in patients with preexisting conditions 4
• Follow-up to ensure treatment effectiveness and consider repeat mycology sampling at end of treatment to confirm mycological clearance 4, 2
• The definitive endpoint for adequate treatment should be mycological cure, not just clinical response 4

Risk Factors for Tinea Pedis

• Swimming, running, warm humid environments 1, 4, 2
• Male gender 1, 4, 2
• Obesity and diabetes 1, 4