What is the recommended treatment for fungal skin infections?

Treatment of Fungal Skin Infections

For superficial fungal skin infections, topical azoles (clotrimazole, miconazole) or polyenes (nystatin) are the first-line treatment for Candida skin infections and paronychia, while dermatophyte infections (tinea corporis/cruris) respond to either topical or short-course oral therapy with azoles or terbinafine. 1

Candidal Skin Infections

Topical therapy is highly effective for primary Candida skin infections:

• Topical azoles (clotrimazole, miconazole) or nystatin are recommended for intertrigo and other non-hematogenous Candida skin infections 1
• These infections typically occur in skin folds, especially in obese and diabetic patients 1
• Keeping the infected area dry is equally important as antifungal therapy 1
• For paronychia, drainage is the most critical intervention, with topical antifungals as adjunctive therapy 1

Dermatophyte Infections (Tinea Corporis/Cruris/Pedis)

Oral therapy is often preferred for widespread or resistant dermatophyte infections:

Tinea Corporis and Tinea Cruris:

• Fluconazole 50-100 mg daily or 150 mg once weekly for 2-3 weeks 2
• Itraconazole 100 mg daily for 2 weeks or 200 mg daily for 7 days 2
• Terbinafine 250 mg daily for 1-2 weeks 2
• Topical allylamines (terbinafine, naftifine, butenafine) are fungicidal and preferred over fungistatic azoles when using topical therapy, as they achieve high cure rates with treatment as short as 1 week 3

Tinea Pedis:

• Fluconazole 150 mg once weekly (pulse dosing) 2
• Itraconazole 100 mg daily for 2 weeks or 400 mg daily for 1 week 2
• Terbinafine 250 mg daily for 2 weeks 2

Important Caveat - Emerging Resistance:

• For Trichophyton mentagrophytes ITS genotype VIII (T. indotineae), there is usually terbinafine resistance 4
• Itraconazole is the drug of choice for terbinafine-resistant dermatophytoses 4
• Species identification and resistance testing should be considered for treatment-refractory cases 4

Pityriasis Versicolor

Short-course oral azole therapy is effective:

• Fluconazole 400 mg as a single dose 2
• Itraconazole 200 mg daily for 5-7 days 2
• Terbinafine is ineffective for pityriasis versicolor 2
• Topical antimycotics can be used for mild cases 4

Tinea Capitis

Oral systemic therapy is always required as topical agents cannot penetrate hair follicles adequately 1:

• Griseofulvin remains the only licensed product for children in the UK, dosed at 20-25 mg/kg daily for 6-8 weeks 1
• Treatment protocols should reflect local epidemiology - griseofulvin is more effective for Microsporum species (88.5% response) than Trichophyton species (67.9% response) 1
• Terbinafine granules (weight-based dosing) are effective alternatives, particularly for Trichophyton infections, though unlicensed for children in some countries 1
• Adjunctive antifungal shampoos (ketoconazole 2%, selenium sulfide 1%, or povidone-iodine) reduce spore transmission 1

Candidal Onychomycosis

Oral therapy is required as topical agents are usually ineffective 1:

• Itraconazole is preferred over terbinafine for Candida onychomycosis, as terbinafine has limited and unpredictable activity against Candida species 1
• Griseofulvin has been largely replaced by more effective agents 1

Key Clinical Pitfalls

• Fungicidal agents (allylamines) are preferred over fungistatic agents (azoles) for dermatophyte infections because patients often stop treatment when skin appears healed (typically after 1 week), and fungi recur more often with fungistatic drugs 3
• Yeast infections (Candida) respond poorly to allylamines - azole drugs are preferred 3
• Always combine oral antifungal treatment with topical therapy for optimal outcomes 4
• Fluconazole should be used with caution in patients with liver dysfunction, and liver function should be monitored if abnormalities develop 5
• High-dose fluconazole (400-800 mg/day) during pregnancy is associated with congenital anomalies and should be avoided 5