What is the recommended treatment for a fungal skin infection in a 7-year-old patient?

Treatment of Fungal Skin Infection in a 7-Year-Old

For widespread dermatophyte infections (tinea corporis, tinea pedis), oral terbinafine is the preferred first-line systemic therapy in children, while topical azoles or nystatin are first-line for localized Candida skin infections, with oral fluconazole reserved for extensive candidal involvement. 1

Diagnostic Confirmation Before Treatment

• Confirm the diagnosis with potassium hydroxide (KOH) preparation to visualize hyphae (dermatophytes) or yeast forms (Candida) before initiating treatment, as this distinction is critical for selecting the appropriate antifungal agent 1
• Culture on Sabouraud agar with cycloheximide should be performed, with plates incubated for at least 2 weeks to identify the specific organism 2
• In cases with highly typical clinical features (scaling, lymphadenopathy, or alopecia for tinea capitis), it is reasonable to start therapy immediately while awaiting culture results 2

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

Localized Dermatophyte Infections

• Topical antifungals are appropriate for limited disease: terbinafine 1% cream, clotrimazole, or miconazole applied twice daily for 2-4 weeks 1, 3
• Fungicidal agents (terbinafine, naftifine, butenafine) are preferred over fungistatic azoles because they achieve high cure rates with treatment as short as 1 week and reduce recurrence if patients stop treatment early 3

Widespread Dermatophyte Infections

• Oral terbinafine is the preferred systemic agent due to its fungicidal properties and high cure rates (approximately 90% mycological cure) 1, 4
• Dosing for terbinafine in children: weight <20 kg: 62.5 mg/day; 20-40 kg: 125 mg/day; >40 kg: 250 mg/day 2
• Treatment duration: 2-4 weeks for tinea corporis/cruris, 4-8 weeks for tinea pedis 5

Alternative Systemic Options for Dermatophytes

• Griseofulvin remains the only FDA-licensed product for tinea in children and is an effective alternative if terbinafine is unavailable or contraindicated 2, 1
• Griseofulvin dosing: 10 mg/kg/day (typically 125-250 mg daily for children 30-50 lbs, 250-500 mg daily for >50 lbs) for 2-4 weeks for tinea corporis 5
• Take griseofulvin with fatty food to increase absorption and bioavailability 2
• Itraconazole can be used at 5 mg/kg/day in children ≥2 years, though it requires therapeutic drug monitoring with target trough concentration ≥0.5 mg/L 1, 2

Treatment for Candida Skin Infections

Localized-to-Moderate Candida Infections

• Topical azoles (clotrimazole, miconazole) or nystatin are first-line with cure rates of 73-100% 1
• Apply twice daily until clinical and mycological cure is achieved 2
• Keep infected areas dry, as moisture promotes Candida growth 2

Extensive Candida Skin Infections

• Oral fluconazole is the systemic agent of choice for widespread Candida skin infections 1, 6
• Fluconazole dosing: 3-6 mg/kg daily 1
• The Infectious Diseases Society of America recommends fluconazole for all mucosal and extensive cutaneous candidiasis in children 1, 6

Critical Management Points

Preventing Transmission and Reinfection

• Treat all family members simultaneously, as anthropophilic dermatophytes can affect over 50% of household contacts 1
• Cleanse fomites (shared towels, clothing, bedding) with bleach or 2% sodium hypochlorite solution 1
• Good personal hygiene is essential and should be emphasized as an adjunct to antifungal therapy 5, 7
• Concomitant use of appropriate topical agents is usually required, particularly for tinea pedis 5

Treatment Duration and Monitoring

• Continue treatment until mycological cure is achieved, not just clinical improvement, to prevent relapse 1
• Clinical relapse will occur if medication is discontinued before the infecting organism is completely eradicated 5
• For dermatophyte infections, representative treatment periods are: tinea corporis 2-4 weeks, tinea pedis 4-8 weeks 5

Common Pitfalls to Avoid

• Do not use topical therapy alone for tinea capitis or onychomycosis, as systemic therapy is required for these infections 2, 8
• Azole drugs (fluconazole, itraconazole) are less effective against dermatophytes than terbinafine but are preferred for Candida infections 3
• In tinea pedis, yeasts and bacteria may be involved alongside dermatophytes; griseofulvin will not eradicate these associated infections 5
• Fungistatic azoles require longer treatment courses and have higher recurrence rates if stopped prematurely compared to fungicidal agents like terbinafine 3