The term trachyonychia is a useful one to describe roughening of the surface of many nails due to various causes. Psoriasis and alopecia areata are responsible for some cases. Lichen planus can roughen nails but the change is usually limited to a few nails and accompanied by discomfort. In many cases no cause can be found and these cases are somewhat arbitrarily listed either as twenty nail dystrophy of childhood or severe nail dystrophy.