“…The fissural lesions are called by him dystrophia longitudinalis fissuriformis. In some cases median longitudinal ridges (striae) have been observed, sometimes combined with fissures [1,8,12,26]. Another characteristic type is a longitudinal nail dystrophy consisting of a median fissure, with radiating, dark-colored side branches, sloping backward towards the base, giving the aspect of an arrowhead or a fir tree [13, 14.…”