What is the treatment for a widespread fungal skin infection in a 10-year-old patient?

Treatment of Widespread Fungal Skin Infection in a 10-Year-Old

For a 10-year-old with widespread fungal skin infection, oral systemic antifungal therapy is required, with the specific agent depending on whether the infection is dermatophyte (tinea) or yeast (Candida) in origin.

Diagnostic Confirmation Required First

• Confirm the diagnosis with potassium hydroxide (KOH) preparation to visualize hyphae (dermatophytes) or yeast forms (Candida) before initiating treatment 1
• This distinction is critical because treatment differs significantly between dermatophyte and Candida infections 1

Treatment for Widespread Dermatophyte (Tinea) Infections

First-Line Systemic Therapy

Oral terbinafine is the preferred systemic agent for widespread dermatophyte infections in children, including tinea corporis when extensive 1, 2:

• Dosing based on weight 3, 2:
  • Children 20-40 kg (44-88 lbs): 125 mg daily
  • Children >40 kg (>88 lbs): 250 mg daily
• Duration: 2-4 weeks for tinea corporis 3, 2
• Terbinafine is fungicidal (kills fungi) rather than fungistatic, allowing shorter treatment courses with high cure rates 4, 2

Alternative Systemic Therapy

Griseofulvin remains an effective alternative, particularly if terbinafine is unavailable or contraindicated 5, 3:

• Dosing: 10 mg/kg/day for children over 2 years 3
  • Children 30-50 lbs: 125-250 mg daily
  • Children >50 lbs: 250-500 mg daily
• Duration: 2-4 weeks for tinea corporis 3
• Must be continued until organism is completely eradicated 3

Important Considerations for Dermatophyte Treatment

• Itraconazole can be used at 5 mg/kg/day in children ≥2 years, though it requires therapeutic drug monitoring (TDM) 5
• Fluconazole is not licensed for tinea in children <10 years in the UK, though it is used in other countries 5
• Topical antifungals alone are insufficient for widespread infections 6, 7

Treatment for Widespread Candida Skin Infections

For Localized-to-Moderate Candida Infections

Topical azoles or nystatin are first-line 1:

• Clotrimazole or miconazole cream applied twice daily for 1-2 weeks 1
• Nystatin is equally effective with cure rates of 73-100% 1
• Keep affected areas dry - this is essential for treatment success 1

For Extensive Candida Infections Requiring Systemic Therapy

Oral fluconazole is the systemic agent of choice for Candida 5:

• Dosing: 3-6 mg/kg daily 5
• Duration depends on extent and severity but typically 1-2 weeks for cutaneous infections
• Fluconazole is licensed for mucosal candidiasis in all children 5

Critical Management Points

Adjunctive Measures (Essential for Success)

• Good personal hygiene is mandatory and must be maintained throughout treatment 3, 6
• Treat all family members if anthropophilic dermatophytes (like T. tonsurans) are identified, as >50% may be affected 5
• Cleanse fomites (hairbrushes, combs) with bleach or 2% sodium hypochlorite solution 5

Treatment Endpoint

• Continue medication until mycological cure is achieved, not just clinical improvement 5, 3
• Clinical relapse will occur if treatment is stopped before organism eradication 3
• Consider repeat microscopy/culture to confirm clearance 5

Common Pitfalls to Avoid

• Do not use topical therapy alone for widespread infections - systemic therapy is required 6, 7
• Do not stop treatment when skin appears healed - this leads to recurrence, especially with fungistatic agents 4
• Do not use terbinafine for Candida infections - azoles are preferred for yeast 1, 4
• Ensure compliance with what may be several weeks of treatment 6

Drug Interactions and Monitoring

• Griseofulvin and azoles have significant drug interactions with immunosuppressants, warfarin, and other medications 5
• Itraconazole requires therapeutic drug monitoring when used 5
• Monitor for hepatotoxicity with prolonged azole therapy 5