Abstract Deformities are often considered together with dystrophies, but the two are slightly different;deformities are generally considered to be gross changes in nail shape, whereas dystrophies are changes in nail texture or composition (eg, onychomycosis).About 50% of nail dystrophies result from fungal infection. The remainder result from various causes, including trauma, congenital abnormalities, psoriasis, lichen planus, benign tumors,and occasionally cancer.