What is the treatment for foot fungus (onychomycosis)?

Treatment of Foot Fungus (Onychomycosis)

Terbinafine is the first-line treatment for dermatophyte onychomycosis (the most common type of foot fungus) with the highest efficacy rates, followed by itraconazole as the next best alternative. 1, 2

Systemic Treatment Options

First-Line Treatments

• Terbinafine: 250 mg per day for 12-16 weeks for toenail infections (6 weeks for fingernail infections) 1

  • Generally preferred over itraconazole due to higher efficacy against dermatophytes 1
  • Baseline liver function tests and complete blood count recommended in patients with history of hepatotoxicity or hematological abnormalities 1
  • Common side effects include headache, taste disturbance, and gastrointestinal upset 1

• Itraconazole: 200 mg per day for 12 weeks continuously, or as pulse therapy (400 mg per day for 1 week per month) 1

  • Two pulses for fingernails and three pulses for toenails 1
  • First-line treatment for Candida onychomycosis due to shorter treatment duration 1
  • Contraindicated in heart failure; monitor hepatic function in patients with pre-existing liver issues 1

Alternative Treatments

• Fluconazole: 150-450 mg per week for at least 6 months in toenail infections (3 months for fingernails) 1

  • Useful alternative when patients cannot tolerate terbinafine or itraconazole 1
  • Monitor liver function tests in high-dose or prolonged therapy 1

• Griseofulvin: 500-1000 mg per day for 12-18 months in toenail infection 1

  • Lower efficacy and higher relapse rates compared to terbinafine and itraconazole 1
  • Should be taken with fatty food to increase absorption 1

Topical Treatment Options

• Topical treatments generally have limited efficacy compared to oral agents 2

• Amorolfine 5% nail lacquer: Applied once or twice weekly for 6-12 months 2

  • Useful for superficial and distal onychomycosis 1
  • Approximately 50% effective in distal toenail onychomycosis 2

• Ciclopirox 8% lacquer: Applied once daily for up to 48 weeks 2

  • Mycological cure rates of 34% (versus 10% with placebo) 2

Treatment Selection Based on Pathogen

• For dermatophytes (most common): Terbinafine is most effective 1, 2
• For Candida species: Itraconazole is first-line treatment 1
• For nondermatophyte molds: Itraconazole has broader antimicrobial coverage than terbinafine 1
  • Aspergillus responds well to itraconazole 1
  • Scopulariopsis, Fusarium, and Acremonium may have reduced susceptibility to antifungals 1

Prevention of Recurrence

• Recurrence rates can be high (40-70%) 1
• Always wear protective footwear in public facilities like hotel rooms, gyms, and changing rooms 1
• Apply antifungal powders containing miconazole, clotrimazole, or tolnaftate in shoes and on feet 1
• Wear cotton, absorbent socks and keep nails short 1
• Avoid sharing toenail clippers 1
• Consider discarding old footwear or disinfect shoes by:
  • Using naphthalene mothballs in shoes in a tightly tied plastic bag for at least 3 days 1
  • Spraying terbinafine solution into shoes periodically 1
• Treat all infected family members simultaneously 1

Special Considerations

• Confirm diagnosis with mycological testing before starting treatment 1, 3
• Expect cure rates of 70-80% for toenail infections with appropriate oral therapy 1, 2
• Treatment failure may occur due to:
  • Dermatophytomas (dense white lesions of tightly packed hyphae) 1
  • Thick nails (>2 mm), slow outgrowth, severe onycholysis 1
  • Consider partial nail removal for resistant cases 1
• Complete nail regrowth may take up to 18 months due to slow toenail growth 1, 2