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

Treatment for Resistant Athlete's Foot (Tinea Pedis)

For resistant cases of athlete's foot, oral terbinafine 250 mg daily for 1 week is the most effective treatment, providing faster clinical resolution than topical treatments while maintaining similar mycological efficacy. 1

First-Line Treatment Options

Topical Treatments

• Terbinafine 1% cream: Apply twice daily for 1-2 weeks (1 week between toes, 2 weeks on bottom/sides of foot)

  • Provides 93.5% mycological cure rate after just 1 week 1
  • Superior efficacy compared to other antifungals
  • Fungicidal action provides better results than fungistatic agents 2

• Ciclopirox olamine 0.77% cream/gel: Apply twice daily for 4 weeks

  • Achieves ~60% clinical and mycological cure at end of treatment
  • Increases to 85% cure two weeks post-treatment 3
  • Effective against T. rubrum, T. mentagrophytes, and E. floccosum 3

Oral Treatments for Resistant Cases

When topical treatments fail, oral antifungals should be considered:

• Oral terbinafine 250 mg: Once daily for 1 week

  • Faster clinical resolution than topical treatments 3
  • Similar efficacy to 4 weeks of clotrimazole 1% cream 3
  • Well-tolerated but requires monitoring for rare hepatotoxicity or neutropenia 1

• Oral itraconazole 100 mg: Daily for 2 weeks

  • Similar mycological efficacy to terbinafine
  • Slightly higher relapse rate compared to terbinafine 3, 1

• Oral griseofulvin: 0.5g daily (divided doses)

  • Longer treatment duration required (4-8 weeks for tinea pedis) 4
  • Less effective than terbinafine (RR 2.26 in favor of terbinafine) 5
  • Should be used with concomitant topical therapy 4

Prevention of Recurrence

• Apply antifungal powders containing miconazole, clotrimazole, or tolnaftate to shoes and feet 1
• Thoroughly dry between toes after bathing 3
• Wear cotton, absorbent socks and change them daily 1
• Clean athletic footwear periodically 3
• Consider discarding heavily contaminated footwear or decontaminating with naphthalene mothballs in a sealed plastic bag for 3 days for severe cases 1

Common Pitfalls in Treatment

• Inadequate treatment duration: Even with fungicidal agents like terbinafine, premature discontinuation can lead to recurrence 1
• Neglecting environmental factors: Contaminated footwear can cause reinfection 1
• Overlooking bacterial superinfection: In macerated, wet-type athlete's foot, bacteria often contribute to symptoms and may require antibacterial treatment 6
• Missing concomitant infections: Check for tinea cruris or other fungal infections that may serve as reservoirs 1
• Failing to identify causative organism: Prior to therapy, proper identification of the dermatophyte through KOH preparation or fungal culture is essential 4

Treatment Algorithm for Resistant Tinea Pedis

1. Confirm diagnosis with KOH preparation or fungal culture
2. First attempt: Terbinafine 1% cream twice daily for 1-2 weeks
3. If inadequate response: Switch to ciclopirox olamine 0.77% cream twice daily for 4 weeks
4. For resistant cases: Oral terbinafine 250 mg daily for 1 week
5. Alternative oral therapy: Itraconazole 100 mg daily for 2 weeks if unable to tolerate terbinafine
6. Implement preventive measures to avoid recurrence

Remember that tinea pedis is prevalent in warm, humid environments and affects men more than women, with obesity and diabetes being additional risk factors 3.