What is the treatment for skin fungal infections?

Treatment for Skin Fungal Infections

Topical antifungal agents are first-line treatment for most skin fungal infections, with topical azoles (clotrimazole, miconazole) or allylamines (terbinafine, naftifine) being the preferred options, while systemic therapy is reserved for nail infections, extensive disease, or treatment failures. 1, 2

Treatment Algorithm by Infection Type

Candidal Skin Infections (Skin Folds, Intertrigo)

• Use topical azoles (clotrimazole, miconazole) or polyenes (nystatin) as first-line therapy for 1-2 weeks, with complete cure rates of 73-100% 1, 2
• Keep the infected area dry—this is crucial for treatment success and failure to do so will hinder therapy 1, 2
• This is particularly important in obese and diabetic patients who are prone to skin fold infections 1

Candidal Paronychia (Nail Fold Infection)

• Drainage is the most important intervention, followed by topical antifungal therapy 1, 2
• Combine drainage with topical azoles or polyenes 2

Candidal Onychomycosis (Nail Infection)

• Topical agents alone are usually ineffective—oral therapy is required 1, 2
• Oral itraconazole is the preferred agent for Candida nail infections, as terbinafine has limited activity against Candida 1, 2

Dermatophyte Infections (Tinea Corporis, Tinea Cruris, Tinea Pedis)

• Topical allylamines (terbinafine, naftifine, butenafine) are preferred over azoles for dermatophyte infections because they are fungicidal rather than fungistatic 3, 4
• Fungicidal agents allow treatment times as short as 1 week with high cure rates 3
• Alternative: topical azoles are also effective but require longer treatment duration 3
• For tinea pedis: 250 mg oral terbinafine daily for 2 weeks, or 100 mg oral itraconazole daily for 2 weeks 5
• For tinea corporis/cruris: 250 mg oral terbinafine daily for 1-2 weeks, or 100 mg oral itraconazole daily for 2 weeks 5

Dermatophyte Onychomycosis (Nail Infection)

• Oral terbinafine is generally preferred for dermatophyte nail infections 2
• Oral itraconazole is an alternative to terbinafine 6, 1
• Griseofulvin requires longer treatment: fingernails at least 4 months, toenails at least 6 months 7
• Topical therapy alone should not be used for nail infections 1
• Systemic therapy is almost always more successful than topical treatment 6

Tinea Capitis (Scalp Infection)

• Systemic therapy is required—topical therapy alone is not recommended 1
• Griseofulvin 10 mg/kg daily for 4-6 weeks is the traditional treatment 7

Key Treatment Principles

When to Use Topical vs. Systemic Therapy

• Topical therapy is appropriate for: localized skin infections, superficial white onychomycosis, very early distal lateral subungual onychomycosis 6, 1
• Systemic therapy is required for: nail infections, tinea capitis, extensive infections, or when systemic therapy is not contraindicated 6, 1

Fungicidal vs. Fungistatic Agents

• Allylamines (terbinafine, naftifine, butenafine) are fungicidal—they kill fungal organisms 3, 4
• Azoles (miconazole, clotrimazole, ketoconazole) are fungistatic—they limit fungal growth but depend on epidermal turnover to shed the fungus 3
• Fungicidal drugs are preferred because patients often stop treatment when skin appears healed (usually after 1 week), and fungi recur more often with fungistatic drugs 3

Combination Therapy Considerations

• For infections with significant inflammation and pruritus, consider topical antifungal-corticosteroid combinations (miconazole or terbinafine plus corticosteroid) to concomitantly treat infection, reduce inflammation, and relieve itching 8
• Concomitant use of appropriate topical agents is usually required, particularly for tinea pedis 7

Common Pitfalls to Avoid

• Do not diagnose on clinical grounds alone—the most common cause of treatment failure in the U.K. is incorrect diagnosis 6
• Confirm diagnosis with KOH preparation or fungal culture before initiating treatment 7
• Do not use topical therapy alone for nail infections or tinea capitis—these require systemic treatment 1
• Medication must be continued until the infecting organism is completely eradicated—clinical relapse will occur if stopped prematurely 7
• For tinea pedis, yeasts and bacteria may be involved along with dermatophytes—antifungal agents will not eradicate these associated infections 7