What is the best treatment for tinea unguium?

Treatment of Tinea Unguium (Onychomycosis)

Oral terbinafine 250 mg daily for 6 weeks (fingernails) or 12 weeks (toenails) is the first-line treatment for tinea unguium, with confirmation of diagnosis through laboratory testing prior to initiating therapy. 1

Diagnosis Confirmation

• Prior to treatment initiation, obtain appropriate nail specimens for laboratory testing:
  • KOH preparation
  • Fungal culture
  • Nail biopsy 1
• This confirmation step is crucial to avoid unnecessary treatment and potential side effects

Treatment Algorithm

First-Line Treatment: Oral Terbinafine

• Dosage: 250 mg once daily 1
• Duration:
  • Fingernail infections: 6 weeks 1
  • Toenail infections: 12 weeks 1
• Mechanism: Allylamine antifungal specifically indicated for onychomycosis due to dermatophytes 1
• Clinical effect: Optimal results typically seen months after mycological cure due to time required for healthy nail outgrowth 1

Alternative Systemic Treatments

• Itraconazole: Has shown superior efficacy (66% cure rate) compared to fluconazole (42%), terbinafine (28%), and griseofulvin (14%) in treatment-resistant cases 2
• Dosing options:

  Medication	Dosage	Duration	Indication
  Itraconazole	50-100mg daily	4 weeks	Treatment-resistant cases
  Fluconazole	Variable	Variable	Exceptional circumstances

Topical Treatments

• Generally less effective as monotherapy for nail infections
• Efinaconazole 10% solution has shown promise with improvement rates of:
  • 76.0% for big toenails with <50% involvement
  • 65.4% for big toenails with ≥50% involvement
  • 80.0% for fingernails
  • 89.5% for other toenails 3
• Consider topical therapy for:
  • Patients unable to tolerate oral medications
  • As adjunctive therapy with oral medications
  • Mild cases with limited nail involvement

Monitoring and Safety Considerations

Liver Function Monitoring

• Perform baseline liver function tests before prescribing terbinafine 1
• Periodic monitoring of liver function is recommended during treatment 1
• Immediately discontinue terbinafine if:
  • Biochemical evidence of liver injury develops
  • Patient reports symptoms of liver toxicity (persistent nausea, anorexia, fatigue, vomiting, right upper abdominal pain, jaundice, dark urine, pale stools) 1
• Terbinafine is not recommended for patients with active or chronic liver disease 1

Other Potential Side Effects to Monitor

• Taste disturbance (including loss of taste) 1
• Smell disturbance (including loss of smell) 1
• Depressive symptoms 1
• Hematologic effects (transient decreases in absolute lymphocyte counts) 1

Treatment Endpoints and Follow-Up

• Continue treatment for the full prescribed duration even if clinical improvement is seen earlier
• Optimal clinical effect is seen some months after mycological cure and cessation of treatment 1
• Consider follow-up mycological examination to confirm cure, especially in resistant or recurrent cases 2

Combination Approaches for Resistant Cases

• For difficult cases, consider:
  • Nail avulsion (surgical or chemical) plus oral antifungals 4
  • Combination of topical and oral antifungal therapy 5
  • Chemical nail avulsion using urea paste under occlusion with topical antifungals 4

Common Pitfalls to Avoid

• Treating without confirming diagnosis through laboratory testing
• Discontinuing therapy prematurely when clinical improvement is seen
• Failing to monitor for hepatotoxicity during terbinafine treatment
• Not warning patients about potential side effects (taste/smell disturbances, depressive symptoms)
• Underestimating treatment duration needed for complete cure