How to diagnose and treat Tinea manuum in an adult?

Diagnosis and Treatment of Tinea Manuum in Adults

Diagnostic Confirmation

Obtain mycological confirmation before initiating systemic therapy through KOH microscopy and fungal culture from skin scrapings of the affected palm or interdigital areas. 1

• Use potassium hydroxide (10-30%) preparation for rapid microscopic diagnosis 1
• Culture specimens on Sabouraud agar with cycloheximide for at least 2 weeks to identify the causative organism 1
• The most common pathogens are Trichophyton rubrum (54%) and Trichophyton mentagrophytes complex (24%), with dermatophytes accounting for 86% of positive cultures 2
• Nondermatophyte infections occur in 14% of cases and have significantly poorer treatment outcomes 2

Key clinical features to identify:

• Palm-scale pattern (present in 85.9% of cases) is the most characteristic finding 2
• Itching is the most common symptom (75.7%) 2
• Look for concurrent fingernail onychomycosis (present in 43% of cases) and other fungal skin infections (59.8%) 2
• Assess for "two feet-one hand syndrome" (bilateral plantar tinea pedis with unilateral tinea manuum), which is commonly caused by T. rubrum 3

Important risk factors to document:

• Diabetes mellitus (present in 26.2% of cases) 2
• Prior topical steroid use (23.4% of cases) 2

Treatment Approach

For Localized Disease Without Nail Involvement

Start with topical antifungal therapy for mild to moderate tinea manuum without nail involvement. 4

• Apply terbinafine 1% gel once daily for 1-2 weeks 5
• Alternative: ciclopirox 0.77% cream or gel twice daily for 4 weeks 5
• Alternative: naftifine ointment twice daily for 4 weeks 5

For Extensive Disease or Nail Involvement

Oral antifungal therapy is required when there is nail involvement, extensive disease, or treatment failure with topical agents. 3, 4

Terbinafine 250 mg daily for 2-4 weeks is the preferred first-line systemic treatment for tinea manuum caused by Trichophyton species. 6, 1, 7

• Terbinafine achieved 86% mycological cure at 8 weeks with just 2 weeks of treatment in moccasin-type tinea pedis and tinea manuum 7
• This agent is particularly effective against T. rubrum and T. mentagrophytes 6
• Baseline liver function tests and complete blood count are recommended before initiating therapy 5

Alternative systemic options:

• Itraconazole 100 mg daily for 15 days has an 87% mycological cure rate and is effective against both Trichophyton and Microsporum species 6, 1

• Itraconazole is optimally absorbed with food and acidic pH 5

• Monitor for significant drug interactions with warfarin, certain antihistamines, antipsychotics, midazolam, digoxin, and simvastatin 1

• Contraindicated in heart failure 5, 1

• Fluconazole 150-450 mg per week may be considered as a third-line option for patients unable to tolerate terbinafine or itraconazole, though it is less cost-effective 6

Do not use griseofulvin as first-line treatment due to longer treatment duration, lower efficacy, and higher relapse rates compared to terbinafine 6, 5

Treatment Monitoring and Endpoints

The definitive endpoint for adequate treatment must be mycological cure (negative microscopy and culture), not just clinical improvement. 5, 1, 8

• Repeat mycology sampling at the end of the standard treatment period 5, 1
• Continue monthly sampling until mycological clearance is documented 5, 8
• Clinical improvement alone is insufficient to stop therapy 8
• If clinical improvement occurs but mycology remains positive, continue current therapy for an additional 2-4 weeks 8

Treatment outcomes:

• Complete cure is achieved in 60.5% of dermatophyte infections 2
• Nondermatophyte infections have significantly poorer outcomes with 0% complete cure rate (p = 0.003) 2
• Overall mycological cure rate with systemic antifungal treatment is 56.4% 2

Management of Concurrent Infections

Evaluate and treat all concurrent fungal infections simultaneously, as 59.8% of patients have additional fungal skin infections and 43% have fingernail onychomycosis. 2

• For concurrent onychomycosis, extend terbinafine to 250 mg daily for 6 weeks for fingernails 5, 1
• Alternative: itraconazole 200 mg daily for 12 weeks continuously, or pulse therapy at 400 mg daily for 1 week per month (2 pulses for fingernails) 5, 1
• When toenails are also affected, terbinafine should be continued for 12-16 weeks 5, 1

Prevention of Recurrence

Implement comprehensive prevention strategies to avoid reinfection, as relapses are common. 3

• Avoid skin-to-skin contact with infected individuals 6
• Do not share towels, combs, brushes, or other personal items 6, 1
• Clean all contaminated fomites with disinfectant or 2% sodium hypochlorite solution 6, 8
• Apply antifungal powders (miconazole, clotrimazole, or tolnaftate) to hands and feet 5, 1
• Wear protective footwear in public bathing facilities, gyms, and hotel rooms to prevent reinfection from T. rubrum 5, 1
• Screen and treat family members, especially with anthropophilic species like T. tonsurans, as over 50% may be affected 6, 8

Critical Pitfalls to Avoid

• Do not rely on topical therapy alone when nail involvement is present, as it is usually ineffective 3, 4
• Do not stop treatment based on clinical appearance alone—mycological cure must be confirmed 5, 1, 8
• Do not overlook concurrent fungal infections of feet and nails, which require simultaneous treatment 2
• Do not forget to assess for nondermatophyte infections, which have significantly worse treatment outcomes and may require alternative management strategies 2, 4
• Monitor liver function in patients receiving prolonged systemic antifungal therapy, especially those with pre-existing hepatic abnormalities 1