[Skin manifestations with internal diseases. Finding the origin].

Inspection of the skin in its entirety often turns up initial and orientating symptoms allowing the early detection of internal disorders. For example, the painful ulcerations of pyoderma gangrenosum can provide clues as to the presence of underlying inflammatory bowel or joint or hematologic disturbances. Extremely painful ulcerations with livedoid bleeding located on the lower limbs are indicative of calciphylaxis as a serious complication of terminal renal failure. Periorificial and migratory necrolytic erythema may signal a glucagon-producing carcinoma of the pancreatic islet cells. Pasty, whitish-yellow papules on the face associated with a tendency for developing petechiae may be a manifestation of amyloidosis in a plasmacytoma. Numerous diffuse angiomas covering the body of a younger patient should prompt the physician to consider the genetic enzyme defect of alpha-galactosidase (Fabry's disease). In the case of pacemaker- or defibrillator-associated erythema, unnecessary revision of the device can be avoided if such possibilities are considered. In consultation with the dermatologist, the exact classification of symptoms, an accurate diagnostic work-up, and differential-diagnostic considerations should be undertaken with the aim of enabling early initiation of causal or stabilizing treatments.