dermatophytosen

Dermatophytosen are fungal infections of keratinized tissues such as skin, hair, and nails, caused by dermatophyte fungi. They are common worldwide and may affect several body sites, often in people with warm, moist skin, poor foot hygiene, or immune compromise. Infections are contagious and can spread through direct contact or contaminated surfaces and objects, including clothing, towels, and floors. Zoonotic transmission from animals also occurs.

Causative organisms belong to three genera: Trichophyton, Microsporum, and Epidermophyton. The most frequent human pathogens include Trichophyton rubrum and Trichophyton mentagrophytes, along with Microsporum canis and Epidermophyton floccosum. The clinical presentation varies by site and is commonly categorized as tinea corporis (body skin), tinea cruris (groin), tinea pedis (feet), tinea manus (hands), tinea capitis (scalp), tinea barbae (beard), and tinea unguium (nails).

Clinically, tinea corporis presents as annular, scaly plaques with advancing borders; tinea cruris shows itchy, well-demarcated inguinal lesions; tinea pedis often involves interdigital spaces or a moccasin-type distribution. Tinea capitis may cause scaliness and hair loss; onychomycosis leads to thickened, discolored nails. Diagnosis relies on potassium hydroxide preparation, fungal culture, and, in some cases, microscopy or molecular methods.

Treatment depends on extent and location. Superficial, localized infections typically respond to topical antifungals such as allylamines or azoles. Widespread disease, tinea capitis, or tinea unguium often requires systemic antifungals (eg, terbinafine, itraconazole, or fluconazole) for several weeks to months. Prevention focuses on thorough drying after washing, avoiding shared personal items, treating pets when involved, and decontaminating footwear and surfaces.

Prognosis is generally favorable with appropriate therapy, but relapse and reinfection are common without preventive measures.