What are the presentation and treatment of Tinea pedis (athlete's foot)?

Tinea Pedis Presentation and Treatment

Tinea pedis (athlete's foot) should be treated with topical terbinafine 1% cream applied twice daily for 1 week for interdigital infections or 2 weeks for plantar (moccasin-type) infections, as this provides the highest cure rates with shortest treatment duration. 1, 2

Clinical Presentation

Tinea pedis presents in three main clinical forms:

1. Interdigital (most common)

   • Maceration, scaling, and fissuring between toes (especially 4th and 5th web spaces)
   • Often accompanied by pruritus, burning, and malodor

2. Hyperkeratotic (moccasin-type)

   • Diffuse scaling on plantar surface and lateral aspects of foot
   • Chronic presentation with dry, silvery scale
   • May extend to dorsal surface in "moccasin" distribution

3. Vesiculobullous (inflammatory)

   • Vesicles or bullae on instep or anterior plantar surface
   • Often pruritic and painful
   • May be accompanied by secondary bacterial infection

Epidemiology and Risk Factors

• Affects approximately 3% of the world population 3
• More common in:
  • Males
  • Adolescents and adults (peak age 16-45 years)
  • Athletes
  • Diabetics (nearly 3x higher risk)
  • Obese individuals 1

Diagnosis

The accuracy of clinical diagnosis alone is low 3. Recommended diagnostic approach:

• KOH wet-mount examination of skin scrapings from active border
• Fungal culture if necessary (especially for resistant cases)
• Most common causative organisms: Trichophyton rubrum and Trichophyton interdigitale 3

Treatment Algorithm

1. Topical Treatment (First-line for most cases)

• Interdigital tinea pedis:

  • Terbinafine 1% cream twice daily for 1 week 1, 2
  • Achieves 93.5% mycological cure rate after 1 week 1

• Moccasin-type (plantar/sides of foot):

  • Terbinafine 1% cream twice daily for 2 weeks 2

• Alternative topical options:

  • Ciclopirox olamine 0.77% cream/gel twice daily for 4 weeks (60-85% cure rate) 1
  • Miconazole, clotrimazole, or tolnaftate (less effective than terbinafine) 1

2. Oral Treatment (For severe, extensive, or resistant cases)

• Terbinafine 250 mg once daily for 1 week

  • Provides faster clinical resolution than topical treatments 1

• Alternatives:

  • Itraconazole 100 mg daily for 2 weeks (slightly higher relapse rate than terbinafine) 1
  • Fluconazole (for those unable to tolerate terbinafine or itraconazole) 1

Prevention and Management of Recurrence

• Thoroughly dry between toes after bathing
• Wear cotton, absorbent socks and change daily
• Wear well-fitting, ventilated shoes; change shoes at least once daily
• Apply antifungal powders to shoes and feet
• Clean athletic footwear periodically
• Treat all infected family members simultaneously 1

Common Pitfalls and Caveats

1. Inadequate treatment duration

   • Even with fungicidal agents like terbinafine, insufficient treatment time leads to recurrence 1

2. Neglecting environmental factors

   • Contaminated footwear can cause reinfection
   • Consider discarding heavily contaminated footwear or decontaminating with naphthalene mothballs in a sealed plastic bag for 3 days 1

3. Missing concomitant infections

   • Check for tinea cruris or other dermatophyte infections 1

4. Misdiagnosis

   • Clinical appearance alone is unreliable; confirm with KOH preparation 3

5. Monitoring for side effects

   • Watch for rare hepatotoxicity or neutropenia with oral terbinafine 1

6. Untreated cases

   • May persist and progress to more extensive infection 3