[Skin fibrosis in hyperthyroidism treated by sotalol and radioactive iodine (author's transl)]

The authors present detailed data about skin fibrosis appearing in hyperthyroidism treated by Sotalol and radioactive iodine. Cutaneous thickening is discovered quite rapidly when the patient is monitored daily (as in case 4). It is asymptomatic and no other features of scleroderma are found. Regression occurs within 4-10 months. Histologically, fibrosis is located in the entire dermis. Dermal appendages are normal and no inflammatory changes occur. No anomalies of collagen structure and fibroblasts have been observed ultrastructurally. Immunological studies (direct immunofluorescence of the skin, lymphocyte transformation and leucocyte migration tests with Sotalol) were normal. The mechanism is unknown, but an immunological or a toxic one is excluded; however a pharmacological action is possible. The role of other betablockers must be assessed by a randomised study.