Dermatofitler

Dermatofitler, or dermatophytes, are a group of fungi that feed on keratin and cause infections of the skin, hair, and nails in humans and animals. They belong to a limited number of genera, primarily Trichophyton, Microsporum, and Epidermophyton. These organisms colonize keratinized tissues by producing keratinases, enabling superficial infection without deep tissue invasion.

In humans, infections are collectively called dermatophytosis or tinea and are named for the location: tinea pedis (foot), tinea corporis (body), tinea cruris (groin), tinea capitis (scalp), and onychomycosis (nail).

Transmission occurs via direct contact with an infected person or animal, or via contaminated surfaces and items (fomites). Risk factors include warm, humid environments, communal bathing facilities, occlusive footwear, diabetes, immunosuppression, and compromised footwear hygiene. Animals such as cats and dogs can carry dermatophytes and transmit infections to humans.

Diagnosis combines clinical assessment with laboratory tests. Potassium hydroxide (KOH) preparation reveals fungal elements; fungal culture on Sabouraud dextrose agar confirms species. Molecular methods and Wood's lamp examination may aid diagnosis, though not all species fluoresce.

Treatment emphasizes topical antifungals (azoles, allylamines) for mild, localized disease; systemic antifungals (terbinafine, itraconazole, fluconazole) for extensive skin involvement or nail/hair infections. Prevention includes avoiding shared towels or sandals, keeping skin dry, and treating infected pets; complete cure requires addressing all affected sites and, in some cases, household members or pets.