“…Typically, in a chronic course, coarsening, scaling, and hyperpigmentation of the skin are also found, as well as painful fissures on the surfaces of the hands and feet. 2 Histologically, orthohyperkeratosis can be seen initially, with atrophy of the epidermis, flattening of the rete ridges, and dermal fibrosis in the final stage. The exact pathomechanism of photosensitivity remains to be conclusively established.…”