What is the treatment for nail Tinea (fungal infection of the nail)?

Treatment of Nail Tinea (Onychomycosis)

Oral terbinafine (250mg once daily) is the first-line treatment for nail fungal infections, with 12 weeks of therapy for toenails and 6 weeks for fingernails. 1

Diagnosis Confirmation

Before initiating treatment, proper diagnosis is essential:

• Laboratory confirmation through:

  • KOH preparation (direct microscopy)
  • Fungal culture
  • Nail biopsy in doubtful cases 2, 1

• Sample collection:

  • For distal lateral subungual onychomycosis (DLSO): Collect subungual debris from the most proximal part of infection
  • For superficial white onychomycosis (SWO): Scrape the surface of the infected nail plate 3

Treatment Algorithm

First-line Treatment:

• Oral terbinafine 250mg daily
  • Toenails: 12 weeks
  • Fingernails: 6 weeks
  • Efficacy: 70-80% for toenails, 80-90% for fingernails 1
  • Advantages: Higher cure rates, fewer drug interactions, shorter treatment duration 1, 2

Second-line Treatment:

• Oral itraconazole 200mg daily
  • 12 weeks continuous therapy
  • Efficacy: ~46% mycological cure rate 3, 1

Alternative Treatment:

• Fluconazole 150-450mg once weekly
  • At least 6 months treatment
  • Useful when terbinafine or itraconazole cannot be tolerated 1, 4

Topical Treatments:

Appropriate for mild cases, early disease, or when oral therapy is contraindicated:

• Amorolfine 5% nail lacquer
• Ciclopirox 8% lacquer
• Efinaconazole 10% solution
• Tioconazole 28% solution 1

Special Populations

Immunocompromised Patients:

• Terbinafine is preferred due to lower risk of drug interactions 5
• May require longer treatment duration
• More difficult to treat with higher recurrence rates 5

Diabetic Patients:

• Terbinafine is preferred due to lower risk of drug interactions 1
• Consider topical treatments for mild-to-moderate infections when drug interaction risk is high

Pediatric Patients:

• Terbinafine dosing based on weight:
  • <20kg: 62.5mg/day
  • 20-40kg: 125mg/day

  • 40kg: 250mg/day 1

Prevention of Recurrence

Recurrence rates are high (40-70%), so preventive measures are crucial:

• Keep nails short and clean
• Dry feet thoroughly after bathing
• Wear cotton socks and change them daily
• Apply antifungal powders to shoes and feet
• Avoid sharing nail clippers
• Wear protective footwear in public areas
• Treat concomitant fungal infections promptly 3

Monitoring and Follow-up

• Clinical improvement may take months after mycological cure due to the time required for healthy nail growth 2
• Treatment success depends on the newly grown-out nail plate being fungus-free 3
• Follow-up should assess both clinical improvement and mycological cure

Common Pitfalls and Treatment Failures

• Incorrect diagnosis: The most common cause of treatment failure is treating without laboratory confirmation 3
• Inadequate treatment duration: Complete the full course even if improvement is seen early
• Dermatophytomas: Dense white lesions beneath the nail may require mechanical removal before antifungal therapy 3
• Unrealistic expectations: Inform patients that visible improvement takes months due to slow nail growth
• Failure to address predisposing factors: Concurrent tinea pedis must be treated 1

In cases of treatment failure, options include:

• Switching to an alternative antifungal
• Partial nail removal plus antifungal therapy
• Complete nail avulsion with antifungal therapy 1

Remember that onychomycosis is a recalcitrant infection where pathogenic dermatophytes may survive in a dormant form during treatment 6, making complete adherence to therapy and preventive measures essential for successful outcomes.