Proximal subungual onychomycosis (Q103762)

Proximal subungual onychomycosis is the least common form onychomycosis in healthy persons. It occurs when the infecting organism, usually Trichohyton rubrum, invades the nail unit through the proximal nail fold, penetrating the soft, newly formed nail plate before then migrating distally. Fingernails and toenails are equally affected. It usually occurs in immunocompromised persons, especially in association with HIV, but can develop following local trauma.