Some nervous habits damage the nails and some people may bite or pick up their cuticles and the skin around the nails. In the common habit tic nail dystrophy, the cuticle of the thumbnail is the target for picking or rubbing. This repetitive trauma causes a ladder pattern of transverse ridges and grooves to run up the center of the nail plate. A 15-year-old boy presented with bilateral thumbnails medial dystrophy due to nail cuticle and plate picking of three years duration.