skin disorders
Deformities, Dystrophies, and Discoloration of the Nails
Median nail dystrophy
In median nail dystrophy, small cracks in the center of the nail extend to the sides and eventually look like the branches of an evergreen tree (such as a Christmas tree). The cause of median nail dystrophy is unknown in some cases, but repeated injuries, including frequent use of computer keyboards and similar devices, are thought to play a role. The person must stop injuring the nails. Treatment withtacrolimusointment has been shown to help in some cases. 