Onychomycosis.

subungual onychomycosis, which is the typical appearance seen in most dermatophyte infections: the disease spreads from the hyponychium into the nail and then progresses proximally, frequently along the lateral margins to affect the whole nail. Superficial white onychomycosis can be caused by a dermatophyte, usually Trichophyton mentagrophytes var. interdigitale or by nondermatophytic moulds. There is typically a white, crumbly patch on the surface of the nail. Proximal subungual onychomycosischomycosis, where the disease starts at the proximal region of the nail, is associated with immunocompromised patients such as those suffering from AIDS. Total dystrophic onychomycosis can be seen as the result of a long-standing dermatophyte infection but it is also a characteristic feature in patients with chronic mucocutaneous candidosis. There are other clinical patterns associated with Candida infection and the most frequent of these is chronic paronychia. Distal nail disease may also occur but the infections are usually secondary and the appearance will depend on the patient’s underlying disease.