What is the recommended treatment for tinea unguium (fungal infection of the nail)?

Treatment for Tinea Unguium (Fungal Nail Infection)

Oral terbinafine is the first-line treatment for tinea unguium (onychomycosis) due to its superior efficacy and relatively low risk of side effects. 1

Systemic Treatment Options

First-line Treatment

• Terbinafine
  • Dosage: 250 mg once daily 2
  • Duration: 6 weeks for fingernails, 12 weeks for toenails 2
  • Efficacy: Mycological cure rates of 73-94% 1
  • Mechanism: Inhibits squalene epoxidase, essential for fungal cell wall synthesis 3
  • Prior to treatment: Confirm diagnosis with KOH preparation, fungal culture, or nail biopsy 2
  • Monitoring: Baseline liver function tests recommended; discontinue if liver injury develops 2
  • Side effects: Headache, taste disturbance, gastrointestinal upset 1

Alternative Systemic Treatments

• Itraconazole

  • Recommended for Candida infections and nondermatophyte molds 1
  • Dosage: 200 mg daily continuous therapy or pulse therapy for 12 weeks 1
  • Efficacy: Mycological cure rate of 45.8% at 48 weeks 1
  • Broader antimicrobial coverage than terbinafine 1
  • Higher risk of drug interactions than terbinafine 1

• Fluconazole

  • Dosage: 150-450 mg once weekly for at least 6 months for toenail infections 1
  • Useful alternative when patients cannot tolerate terbinafine or itraconazole 1

• Griseofulvin (less preferred)

  • Dosage: 500-1000 mg daily 4
  • Duration: At least 4 months for fingernails, at least 6 months for toenails 4
  • Lower efficacy (3-38% for toenails) and higher relapse rates compared to newer agents 5, 1
  • Only antifungal agent specifically licensed for children with onychomycosis 3
  • Pediatric dosage: 10 mg/kg daily 4

Topical Treatment Options

Topical therapy should only be used in superficial white onychomycosis, very early distal lateral subungual onychomycosis, or when systemic therapy is contraindicated 3.

• Amorolfine 5% nail lacquer

  • Application: Once or twice weekly 3
  • Efficacy: Approximately 50% in distal nail infections 3, 1
  • Duration: 6-12 months 3

• Ciclopirox 8% lacquer

  • Application: Once daily 3
  • Duration: Up to 24 weeks for fingernails, up to 48 weeks for toenails 3
  • Efficacy: Mycological cure rates of 34% 1

• Efinaconazole 10% solution

  • Application: Once daily 3
  • Efficacy: Mycological cure rates of 50% 1

• Tioconazole 28% solution

  • Lower efficacy than other topical options 3
  • Contraindicated in pregnancy 1

Treatment Algorithm

1. Confirm diagnosis with KOH preparation, fungal culture, or nail biopsy
2. Assess infection severity and causative organism:
   • For dermatophyte infections (most common): Terbinafine is first choice
   • For Candida or nondermatophyte molds: Consider itraconazole
3. Consider patient factors:
   • Hepatic impairment: Avoid terbinafine, itraconazole, and griseofulvin; consider fluconazole with dose adjustment 1
   • Heart failure: Avoid itraconazole 1
   • High risk of drug interactions: Prefer terbinafine over azoles 1
   • Children: Use weight-based dosing of terbinafine or griseofulvin 1, 4
4. For mild cases or when oral therapy is contraindicated: Use topical therapy
5. For severe or resistant cases: Consider combination therapy (oral + topical) or surgical approaches

Management of Treatment Failure

If treatment fails, consider:

• Poor compliance
• Poor drug absorption
• Immunosuppression
• Dermatophyte resistance
• Subungual dermatophytoma
• Zero nail growth 1

Options include:

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

Prevention of Recurrence

Onychomycosis has high recurrence rates (40-70%) even with established treatments 1. Preventive measures include:

• Keeping nails short
• Avoiding sharing nail clippers
• Wearing protective footwear in public areas
• Applying antifungal powders in shoes and on feet
• Wearing cotton, absorbent socks
• Treating concomitant fungal infections 1

The optimal clinical effect is seen some months after mycological cure and cessation of treatment, as this relates to the period required for outgrowth of healthy nail 2.