What is the appropriate treatment for a quarter-sized rash between the toes?

Treatment of Rash Between Toes

Topical terbinafine 1% cream applied twice daily for 1 week is the most effective first-line treatment for interdigital tinea pedis (athlete's foot), which is the most likely diagnosis for a quarter-sized rash between the toes. 1, 2

Diagnosis and Initial Approach

• The quarter-sized rash between toes is most likely tinea pedis (athlete's foot), which is predominantly caused by dermatophytes like Trichophyton rubrum and T. mentagrophytes 3
• The intertriginous type is most common, characterized by peeling, maceration, and fissuring between the toes 3
• Before applying any treatment, wash the affected area with soap and water and dry completely 2

First-Line Treatment Options

• Topical terbinafine 1% cream is the most effective first-line treatment:

  • Apply twice daily (morning and night) for 1 week for interdigital (between toes) tinea pedis 1, 2
  • Terbinafine relieves associated symptoms including itching, burning, cracking, and scaling 2
  • Terbinafine has higher cure rates and requires shorter treatment duration compared to azole antifungals 4

• Alternative topical options if terbinafine is unavailable:

  • Ciclopirox olamine 0.77% cream/gel applied twice daily for 1-2 weeks (approximately 85% cure rate) 1
  • Clotrimazole 1% cream applied twice daily for 2-4 weeks (less effective than terbinafine but widely available over-the-counter) 1, 5

Management of Severe or Resistant Cases

• If the rash doesn't improve after 1-2 weeks of topical therapy, consider:
  • Oral terbinafine 250 mg once daily for 1 week (for severe or extensive infections) 1
  • Oral itraconazole 100 mg daily for 2 weeks as an alternative 1
  • Systemic therapy should be reserved for severe disease, failed topical therapy, or immunocompromised patients 1

Prevention and Additional Measures

• Thoroughly dry between toes after bathing/showering 1
• Wear well-fitting, ventilated shoes and change socks at least once daily 2
• Apply foot powder after bathing to reduce recurrence 1
• Clean athletic footwear periodically to prevent reinfection 1
• To prevent spread to the groin area (jock itch), cover active foot lesions with socks before wearing underwear 1

Special Considerations

• If the rash appears unusually inflamed or has drainage, consider possible bacterial superinfection which may require antibacterial treatment 6
• For diabetic patients, foot infections require more careful attention as they can lead to more serious complications 6
• If the rash doesn't respond to antifungal treatment, consider alternative diagnoses such as contact dermatitis or bacterial infection 5