What is the treatment for a patient with a fungal infection across all body areas, diagnosed with KOH (potassium hydroxide)?

Treatment of Widespread Fungal Infection Confirmed by KOH

For extensive dermatophyte infections affecting multiple body areas confirmed by KOH preparation, initiate systemic antifungal therapy with oral griseofulvin or fluconazole, as topical therapy alone is inadequate for widespread disease. 1

Systemic Antifungal Therapy

Griseofulvin remains the FDA-approved systemic treatment for extensive dermatophyte infections involving skin, hair, and nails when topical therapy is insufficient. 1

Dosing Regimen

• Adults: Start with 500 mg daily (can be given as 125 mg four times daily, 250 mg twice daily, or 500 mg once daily). 1
• For widespread lesions, initial doses of 750 mg to 1 gram daily may be required, then reduced to 500 mg or less after clinical response. 1
• Pediatric patients (>2 years): 10 mg/kg daily is typically adequate (children 30-50 lbs: 125-250 mg daily; >50 lbs: 250-500 mg daily, in divided doses). 1

Treatment Duration by Site

The medication must be continued until complete eradication of the organism, with specific minimum durations: 1

• Tinea capitis: 4-6 weeks 1
• Tinea corporis: 2-4 weeks 1
• Tinea pedis: 4-8 weeks 1
• Fingernail involvement: At least 4 months 1
• Toenail involvement: At least 6 months 1

Site-Specific Considerations

Tinea Corporis (Body)

• Minimum 72 hours of topical or systemic antifungal therapy required before return to activities if applicable. 2
• For localized lesions, topical terbinafine or naftifine for minimum 72 hours is acceptable. 2
• Extensive and active lesions (confirmed by KOH or treatment review) require systemic therapy. 2

Tinea Capitis (Scalp)

• Systemic therapy is mandatory—topical agents are ineffective for scalp infections. 2
• Minimum 2 weeks of systemic antifungal therapy required. 2

Tinea Pedis and Cruris

• Concomitant topical therapy is usually required alongside systemic treatment. 1
• Exclude from swimming pools and discourage barefoot walking in locker rooms until treatment initiated. 2
• Yeasts and bacteria may coexist with dermatophytes in tinea pedis; griseofulvin does not eradicate these secondary infections. 1

Critical Management Points

Hygiene and Infection Control

• General hygiene measures must be observed to control sources of infection or reinfection. 1
• Appropriate topical agents should be used concomitantly, particularly for tinea pedis. 1

Monitoring Treatment Response

• Clinical relapse will occur if medication is discontinued before complete eradication of the organism. 1
• Continue treatment until the infecting organism is completely eradicated as indicated by clinical or laboratory examination. 1

Common Pitfalls to Avoid

• Do not use griseofulvin for Candida infections—it is ineffective against bacterial infections, candidiasis, and other non-dermatophyte fungi. 1
• Do not rely on topical therapy alone for widespread or multiple-site infections—systemic therapy is required. 1
• Do not stop treatment prematurely when symptoms improve—continue until complete organism eradication to prevent relapse. 1
• Do not assume all fungal infections are dermatophytes—confirm the specific organism, as griseofulvin is ineffective against yeasts like Candida. 1

Alternative Systemic Options

For patients unable to tolerate griseofulvin or with resistant organisms:

• Fluconazole 400 mg daily can be considered for dermatophyte infections, though this is based on extrapolation from other fungal infection guidelines. 2
• Itraconazole or terbinafine may be alternatives, though specific dosing for widespread dermatophyte infections should be individualized based on organism susceptibility.