What is the treatment for dermatophytosis?

Treatment for Dermatophytosis

Terbinafine is the first-line treatment for dermatophyte infections, particularly for onychomycosis, due to its superior efficacy compared to other antifungal agents. 1

Diagnostic Approach

Before initiating treatment:

• Obtain appropriate specimens for laboratory confirmation
  • KOH preparation
  • Fungal culture
  • Nail biopsy (if needed)
• Confirm the diagnosis of dermatophytosis 2

Treatment Algorithm

1. Dermatophyte Onychomycosis

• First-line treatment: Terbinafine

  • Fingernail infection: 250 mg daily for 6 weeks
  • Toenail infection: 250 mg daily for 12 weeks 1, 2
  • Expected cure rates: 80-90% for fingernails, 70-80% for toenails 1

• Second-line treatment: Itraconazole

  • Pulse therapy: 400 mg daily for 1 week per month
  • Fingernail infection: 2 pulses
  • Toenail infection: 3-4 pulses 1

2. Candidal Onychomycosis

• First-line treatment: Itraconazole
  • Same dosage regimen as for dermatophytes
  • 400 mg daily for 1 week per month
  • Fingernail infection: 2 pulses
  • Toenail infection: 3-4 pulses 1

3. Topical Treatment Options

• Limited to very distal infections or superficial white onychomycosis
• Generally inferior to systemic therapy 1
• Options include:
  • Imidazole lotions
  • Amorolfine
  • Ciclopirox nail lacquer 3

Special Considerations

Treatment Failure

If treatment fails, consider:

1. Poor compliance
2. Poor drug absorption
3. Immunosuppression
4. Dermatophyte resistance
5. Zero nail growth
6. Subungual dermatophytoma 1

For persistent cases:

• Consider partial nail removal in combination with antifungal therapy
• Switch to an alternative antifungal agent 1

Emerging Resistance

• Trichophyton indotineae shows increasing resistance to terbinafine
• For resistant strains, itraconazole (200 mg/day for 1-12 weeks) may be more effective 4

Prevention of Recurrence

• Keep nails short
• Wear protective footwear in public facilities
• Use antifungal powders in shoes
• Treat all infected family members simultaneously
• Consider disinfecting footwear 1

Monitoring

• Baseline liver function tests before starting oral therapy
• Periodic monitoring of liver function during treatment
• Discontinue treatment immediately if signs of liver injury develop 2
• Watch for adverse effects:
  • Terbinafine: taste disturbance, headache, gastrointestinal upset
  • Itraconazole: heart failure risk, hepatotoxicity 1

Key Pitfalls to Avoid

1. Treating without mycological confirmation - Always obtain laboratory confirmation before starting systemic therapy 1
2. Inadequate treatment duration - Shorter courses lead to treatment failure
3. Ignoring underlying conditions - Consider immunosuppression in persistent cases 1
4. Missing dermatophytomas - These dense fungal masses may require mechanical removal 1
5. Overlooking reinfection sources - Failure to address contaminated footwear or family members with infection

Remember that clinical improvement may take months after mycological cure due to the time required for healthy nail outgrowth 2.