Diagnosis: Onychomycosis (Fungal Nail Infection)

• Yellow-brown discoloration
• Nail thickening (onychauxis)
• Crumbling, frayed nail edges
• Subungual debris (dark hyperkeratotic material)
• Onycholysis (nail separating from nail bed)

Important: Before starting oral antifungals, laboratory confirmation is recommended. Approximately one-third of clinically suspected onychomycosis cases do not have fungal infection. A KOH preparation, fungal culture, or PCR test should confirm the organism. - Goodman & Gilman's Pharmacological Basis of Therapeutics

Treatment

Step 1: Confirm diagnosis

• KOH preparation of nail clippings/scrapings (quick, cheap)
• Fungal culture (identifies species - important, as treatment differs by organism)
• Nail PCR (most sensitive)

Step 2: Choose antifungal therapy

First-Line: Oral Terbinafine (most effective for dermatophytes)

• Fungicidal; remains in nails for weeks after stopping
• Avoid if: hepatic dysfunction, moderate-severe renal impairment
• Check LFTs before starting; monitor during therapy

Alternative: Oral Itraconazole (preferred if Candida suspected or if terbinafine cannot be used)

Alternative: Oral Fluconazole

• 150-300 mg once weekly for 6-12 months
• Useful when terbinafine or itraconazole are contraindicated

Adjunctive Topical Therapy (add-on, not standalone for severe cases)

• Ciclopirox lacquer 8% - daily application, 48-week course
• Efinaconazole 10% solution - daily x 48 weeks, FDA-approved for toenails
• Tavaborole 5% solution - daily x 48 weeks
• 40% urea cream - recent meta-analysis (PMID 40827600) supports urea as an adjuvant to help debride/thin the nail and improve antifungal penetration

Step 3: Nail debridement

• Mechanical trimming and filing of the thickened nail
• Reduces fungal load and helps topical agents penetrate
• Can be done by a podiatrist or dermatologist; also helpful to do at home with a nail file after soaking

Step 4: Prevention of recurrence

• Keep nails short and dry
• Change socks daily; use breathable footwear
• Use antifungal foot powder in shoes
• Treat tinea pedis (athlete's foot) concurrently if present - it is a major source of reinfection
• Avoid walking barefoot in communal areas (gyms, pools)

When to Refer

• Diagnosis is uncertain
• Nail matrix is involved
• No improvement after adequate treatment
• Immunocompromised patient
• Signs of secondary bacterial infection

Sources: Goldman-Cecil Medicine; Goodman & Gilman's Pharmacological Basis of Therapeutics; PMID 40827600 (2025 meta-analysis on 40% urea adjuvant therapy)

⚠️ Disclaimer: This is for educational purposes only. Please consult a healthcare provider for personal medical advice and before starting any prescription medication.

Treatment Plan: Onychomycosis (Fingernail)

Phase 1 - Confirm Before Treating (Before Day 1)

Approximately 1 in 3 clinically suspected cases are NOT fungal. Confirm before prescribing. - Goodman & Gilman's

Phase 2 - First-Line Systemic Therapy (Weeks 1-6 for fingernails)

• Repeat LFTs at 4-6 weeks
• Watch for: GI upset, taste disturbance (dysgeusia), rash, elevated liver enzymes
• Stop immediately if symptomatic hepatotoxicity develops

Phase 3 - Adjunctive Topical Therapy (Alongside oral, throughout)

Phase 4 - Nail Debridement (Ongoing, Every 2-4 Weeks)

1. Soak the nail in warm water for 10-15 minutes to soften
2. Trim as much of the infected nail as possible with clean nail clippers
3. File the nail surface with an emery board to reduce thickness
4. Apply topical agent immediately after
5. Ideally done by a podiatrist or dermatologist initially; can be maintained at home

Phase 5 - Monitor Treatment Response

• New pink, normal nail growing from the base (proximally)
• Reduction in subungual debris
• Nail no longer thickening or crumbling

Phase 6 - Recurrence Prevention (Long-term)

Special Considerations

Summary Timeline

Day 0        → Confirm diagnosis (KOH + culture) + baseline LFTs
Day 1        → Start Terbinafine 250 mg/day + topical ciclopirox/urea + nail trimming
Week 6       → Stop terbinafine (fingernail) | LFTs recheck
Month 3      → Assess proximal nail regrowth; KOH to confirm clearance
Month 6      → Full clinical and mycological cure expected for fingernail
Month 12+    → Recurrence monitoring and prevention

Sources: Fitzpatrick's Dermatology; Goodman & Gilman's Pharmacological Basis of Therapeutics; Goldman-Cecil Medicine; Practice Guideline PMID 37212291 (S1 Guideline onychomycosis, 2023)

⚠️ This treatment plan is for clinical educational reference. Individual management should be guided by a licensed healthcare provider based on confirmed diagnosis, patient history, and local drug availability.