What is the treatment for onychomycosis (nail infection)?

Treatment for Onychomycosis (Nail Infection)

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

Diagnostic Confirmation Before Treatment

Before initiating any treatment, mycological confirmation of infection is essential:

• Obtain nail specimens for KOH preparation and fungal culture 1, 2
• Identify the causative organism, as treatment differs based on pathogen type

Treatment Algorithm Based on Causative Organism

1. Dermatophyte Infections (Most Common)

• First-line: Oral terbinafine

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

• Second-line: Oral itraconazole

  • Pulse therapy: 400 mg daily for 1 week per month
  • Fingernails: 2 pulses (2 months total) 1
  • Toenails: 3-4 pulses (3-4 months total) 1

2. Candidal (Yeast) Infections

• First-line for nail plate invasion: Oral itraconazole

  • 400 mg daily for 1 week per month
  • Fingernails: 2 pulses (2 months total) 1
  • Toenails: 3-4 pulses (3-4 months total) 1

• For paronychia with yeast infection:

  • Topical treatment with antiseptics and imidazole lotion alternating with antibacterial lotion 1, 3
  • Continue until cuticle integrity is restored (may take several months)

3. Topical Therapy

• Reserved for:

  • Very distal infections
  • Superficial white onychomycosis (SWO)
  • Cases where systemic therapy is contraindicated 1
  • Less than 50% of nail plate affected 3

• Options include:

  • Amorolfine nail lacquer (50% cure rate for distal infections) 1
  • Ciclopirox 8% 4
  • Efinaconazole 10% or tavaborole 5% for mild to moderate cases 4

Treatment Failure Management

If treatment fails despite adequate compliance, consider:

1. Evaluate for subungual dermatophytoma - a tightly packed mass of fungus that prevents drug penetration 1
2. Partial nail removal for resistant cases, followed by antifungal therapy 1
3. Alternative antifungal agent if the first choice was ineffective 1

Complete nail avulsion under ring block prior to treatment can achieve nearly 100% cure rates in resistant cases, though this is not necessary for most patients 1.

Important Monitoring and Precautions

For Terbinafine:

• Monitor for signs of liver toxicity: persistent nausea, anorexia, fatigue, vomiting, right upper abdominal pain, jaundice, dark urine, or pale stools 2
• Watch for taste or smell disturbances and depressive symptoms 2
• Check for drug interactions, especially with tricyclic antidepressants, SSRIs, atypical antipsychotics, beta blockers, or tamoxifen 4

For Itraconazole:

• Monitor liver function for treatment durations longer than 1 month 1
• Be aware of multiple drug interactions, including with anticoagulants, antihistamines, antipsychotics, anxiolytics, digoxin, cisapride, cyclosporine, and statins 1

Prevention of Recurrence

Recurrence rates are approximately 15% one year after completing terbinafine therapy 2. To reduce recurrence:

• Avoid walking barefoot in public places
• Disinfect shoes and socks 4
• Consider prophylactic application of topical antifungals 5

Clinical Significance

Onychomycosis is not merely a cosmetic issue - untreated infection can cause pain, discomfort, physical impairment, and in patients with diabetes or peripheral vascular disease, may lead to serious complications 1, 4. Treatment improves quality of life and reduces public health concerns related to transmission in communal bathing facilities 1.