Skin involvement in familial amyloidotic polyneuropathy

A 3-mm punch biopsy of clinically normal skin was obtained from the forearm of 11 patients from five kinships with familial amyloid polyneuropathy. Seven of the 11 patients had sensory polyneuropathy in the arms as well as the legs. Abnormalities of the autonomic nervous system (nocturnal diarrhea and sphincter abnormalities) were observed in all patients. Four patients had multiple atrophic scars and poorly healed ulcers on the limb; two had petechiae after gentle stroking of the skin. Histopathology revealed amyloid deposits in all 11 skin biopsies (100%). Amyloid infiltration was noted in blood vessels, sweat glands, dermis, and arrector pili muscles. Intracutaneous neural deposits were not found. Skin biopsies from family members at risk may be an effective method of early diagnosis.