Onychomycosis

[Rihanna]

Onychomycosis is a fungal infection of the nails.

(See also Overview of Nail Disorders.)

About 10% of people have onychomycosis, which most often affects the toenails rather than the fingernails. It is most prevalent among older people, particularly men, and people with poor circulation in the feet (peripheral arterial disease [see Foot care]), diabetes (see Foot problems in diabetes), a weakened immune system (caused by a disorder or drug), athlete

[Becky]

Fungal infection of a nail, claw, or hoof; an instance of this.