Pachyonychia congenita tarda affecting only the nails.

A 42-year-old woman presented with complaints of rapidly progressing thickening and yellowish discoloration of the nails for the past 24 months. All nails were affected and fingernails were more thickened than toenails. Her palms and soles were normal. Keratosis pilaris, palmoplantar blistering, hyperhidrosis, leukokeratosis, alopecia, dental malformation, corneal abnormalities and epidermoid cysts were absent. This patient has pachyonychia congenita tarda with clinical manifestations limited to nail involvement.