Dermatofytosis

Dermatophytosis is a fungal infection of keratinized tissues caused by dermatophyte fungi in the genera Trichophyton, Microsporum, and Epidermophyton. In humans it most commonly involves the skin, hair, and nails, and is often referred to by the site of infection, such as tinea corporis (body), tinea cruris (groin), tinea pedis (foot), tinea capitis (scalp), or onychomycosis (nails). The condition is usually superficial, affecting the outer layers of the skin, hair, or nails.

Transmission occurs through direct contact with infected people or animals, or via contaminated objects and surfaces. Athletes, gym users, and those living in warm, humid climates are at higher risk. Zoonotic transmission from domestic animals and pets is common for certain species.

Clinical features vary by site but commonly include circular or annular, scaly, pruritic plaques with an advancing active border and central clearing on skin; interdigital or moccasin-type involvement on the feet; nail discoloration or thickening in nails; and patchy hair loss with scaling in the scalp or beard area.

Diagnosis is based on clinical presentation and can be confirmed by microscopic examination of skin scrapings or nail clippings with potassium hydroxide, culture on dermatophyte media, and occasionally Wood’s lamp examination or molecular tests.

Treatment typically involves topical antifungal agents for limited skin infections, and systemic antifungals (such as terbinafine, itraconazole, or fluconazole) for extensive disease or nail involvement. Response is gradual and completed courses are important to prevent recurrence. Preventive measures include keeping skin dry, avoiding sharing personal items, treating infected pets, and maintaining good foot hygiene.