Nail lesions of psoriasis, eczematous eruptions and ischemic arterial disease can mimic onychomycosis. The KOH test or a culture is Onychomycosis is cause by T rubrum, and some degree of tinea pedis is usually also present. The disease usually begins at the corner of the nail as a yellowish discoloration. As it spreads, the nail begins to separate from its bed distally, resulting in irregular nail dystrophy. The presence of the fungus in the nail or its bed is confirmed by KOH examination or culture.
Topical treatment is ineffective.
Results with griseofulvin by mouth have been disappointing, but response to newer antifungals has been excellent. Itraconazole should be taken with a full meal. This condition is typically known as jock itch or crotch rot. It is common in men and rare in women. Tinea cruris affects the crural fold and inner aspect of one or both thighs.