skin disorders
Deformities, Dystrophies, and Discoloration of the Nails
Deformities and dystrophies associated with skin diseases
Sometimes, skin diseases also affect the nail unit and may change the appearance of the nails. Some drugs given to treat skin diseases can change the nail plate. For example, retinoids, such asisotretinoinand etretinate, can cause dryness and brittleness of the nails. In Psoriasis , nails may have irregular pits (tiny depressions in the surface of the nail), oil spots (yellow-brown spots under the nail), separation of the nail plate from its bed (onycholysis), and thickening and crumbling of the nail plate. Lichen Planus of the nail matrix causes scarring with early nail ridging and splitting, later leading to scarring and pterygium formation. Pterygium of the nail, which is caused by lichen planus, is scarring from the base of the nail outward in a V formation, which leads to loss of the nail. People with Alopecia Areata , a disorder in which round, irregular patches of hair are suddenly lost, may have nail pits that form a geometric pattern. People who have alopecia areata, lichen planus, Atopic Dermatitis (Eczema) , or psoriasis may develop trachyonychia (rough, opaque nails that have ridges and a sandpaper-like appearance). Trachyonychia most frequently occurs in children. This photo shows pits and areas of tan-brown discoloration (called oil spots) in a person who has psoriasis. © Springer Science+Business Media This photo shows lengthwise ridging of the thumbnail in a person who has lichen planus. DR P. MARAZZI/SCIENCE PHOTO LIBRARY This photo shows pterygium (scarring from the base of the nail outward in a V shape) and atrophy (wasting away) of several nails, which can be seen in people who have lichen planus. © Springer Science+Business Media In this photo, the nails are opaque and rough and have a sandpaper-like appearance. © Springer Science+Business Media 