Idiopathic pigmentation of the hands. Professional exogenous ochronosis? A new entity?

A case of ochronosis-like pigmentation of the hands is described. The following criteria were fulfilled: (1) presence of blue to black spots confined to the hands: (2) pitch-black macroscopic appearance of the biopsy specimen; (3) abundance of granular material in the whole connective structures on microscopic examination of an unstained specimen just mounted on a slide; (4) numerous pigmented granules in the elastic and collagen fibers: (5) no family history, abnormal coloration of the urine, taking of drugs, or rheumatism; (6) onset in a manual worker exposed to benzenic substances. This seems to be a new entity, probably a variant of exogenous ochronosis produced by professional contacts with some agents and perhaps a professional benzenic ochronosis.