A nail fungal infection is medically referred to as onychomycosis. Nail fungus is caused by dermatophytes, which are microscopic organisms that invade the nail bed and feed off the keratin in the nail. There are several species of dermatophytic fungi including Epidermophyton, Microsporum and Trichophyton.
Distal Lateral Subungual Onychomycosis
The most common type of nail fungal infection is distal lateral subungual onychomysosis. Caused by the dermatophytic fungi strain Trichophyton rubrum, the fungus invades the nail through the hyponchium, the thickened layer of the skin beneath the free end of the nail and is responsible for nearly 80% of all fungal infections.
White Superficial Onychomycosis
White superficial onychomycosis generally caused by the dermatophytic fungal strain Trichophyton mentagrophytes and accounts for 10% of onychomycosis cases. In the case of white superficial onychomycosis, the fungus invades directly through the nail plate.
Proximal Subungual Onychomycosis
Usually only present in immune-compromised individuals, the least common form of onychomycosis is proximal subungual. A variant of distal lateral subungual onychomycosis, proximal subungual onychomycosis is caused by the dermatophytic fungi strain T. rubrum, the fungus invades the nail through the proximal nail fold, the soft tissue at the base of the nail that protects new emerging nails.
Generally confined to the lower nail plate, fungus invades the nail plate directly.
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