table of contents
🔬 Etiology & Epidemiology
Athlete’s foot is a superficial fungal infection caused by dermatophytes (Trichophyton rubrum, Trichophyton mentagrophytes, or Epidermophyton floccosum). Global prevalence exceeds 15% in adults, with higher incidence in tropical climates and urban populations.
🦠 Transmission Pathways
- Direct contact: Shared footwear, towels, or bathing facilities
- Environmental reservoirs: Contaminated floors in gyms, swimming pools, or communal showers
- Autoinoculation: Spread to other body regions (e.g., groin, hands) via scratching
⚠️ Risk Factors
| Category | Specific Risks |
|---|---|
| Occupational | Athletes, military personnel, miners |
| Behavioral | Prolonged use of occlusive footwear, poor foot hygiene |
| Medical | Diabetes mellitus, immunosuppression, peripheral vascular disease |
🚨 Clinical Progression
- Early Stage:
- Pruritus between toes (esp. 4th-5th webspace)
- Scaling or maceration
- Chronic Phase:
- Hyperkeratosis of soles
- Fissuring and erythema
- Complications:
- Secondary bacterial infections (cellulitis, lymphangitis)
- Onychomycosis (nail involvement in 30% cases)
🛡️ Prevention Strategies
- Avoid shared footwear/socks
- Use antifungal powders in shoes
- Dry interdigital spaces thoroughly post-washing
- Wear moisture-wicking socks (e.g., merino wool, synthetic blends)
💊 Treatment Protocol
First-line:
- Topical azoles (clotrimazole 1% BID × 4 weeks)
- Allylamines (terbinafine 1% daily × 1-2 weeks)
Severe/Recurrent Cases:
- Oral terbinafine 250 mg/day × 2-6 weeks
- Regular follow-up with potassium hydroxide (KOH) microscopy
Critical Note: 67% of patients discontinue treatment prematurely, increasing recurrence risk. Patient education on complete therapeutic courses is essential.
Early intervention prevents household transmission clusters. Annual screening recommended for high-risk groups.