Non-infectious inflammatory disorders of the nail apparatus.

Inflammatory non-infectious diseases of the nails are not uncommon. The nail changes may look different in the same diseases, but also very much alike in various different nail disorders depending on which particular structure of the nail apparatus is involved. Of all skin diseases, psoriasis is the one with the most frequent nail involvement. The presence of many pits allows the diagnosis to be made, but salmon spots and onycholysis are also characteristic features. Lichen planus may occur isolated on the nails or in association with lesions of the skin and adjacent mucosal membranes. Longitudinal striations and loss of the nail plate shine are the most frequent features of nail lichen planus. The more severe the alopecia areata is and the younger the patient is, the more often it affects the nail, usually with a rough surface and loss of shine. Eczemas and various autoimmune dermatoses may also affect the nails but the changes are not clinically specific.