Fungal Skin Infections: Athlete's Foot, Ringworm, Tinea Versicolor, and Candidiasis

Dermatophytes and yeasts cause superficial cutaneous infections. "Mold" is a misnomer; these are fungi.

Common Infections

Infection	Organism	Typical Presentation
Tinea pedis (Athlete's foot)	Trichophyton rubrum, mentagrophytes	Interdigital scaling, fissures; moccasin (hyperkeratotic) or vesicular
Tinea corporis (Ringworm)	Trichophyton, Microsporum	Annular, scaly, erythematous plaque with central clearing
Tinea versicolor	Malassezia furfur (yeast)	Hypo/hyperpigmented macules on trunk; fine scale; KOH: "spaghetti and meatballs"
Cutaneous candidiasis	Candida albicans	Intertriginous: beefy red, satellite pustules; nail: onychomycosis

Complications

• Secondary bacterial infection (cellulitis, abscess).
• Rare: deep tissue invasion (immunocompromised).

Prevention

• Keep skin dry (powders, moisture-wicking fabrics).
• Avoid shared towels, footwear.
• Manage diabetes, immunosuppression.

Treatment

• Topical azoles (clotrimazole, terbinafine) 2–4 weeks.
• Oral terbinafine, itraconazole, fluconazole for extensive/refractory.
• Selenium sulfide shampoo for tinea versicolor.