Deposits of plasma proteins in the skin during treatment with carbamazepine and diphenylhydantoin.

Biopsies from skin of normal appearance from 18 patients treated with carbamazepine and diphenylhydantoin were investigated by a direct immunofluorescence technique. Seventeen had deposits of plasma proteins at the dermoepidermal junction, 16 had deposits in the vessel walls, and one had autofluorescence of the nuclei in the epidermis and vessel walls. These findings did not correlate with changes in serum IgG, IgA, IgM, IgD, IgE or alpha 2-macroglobulin. Eight patients had elevated alkaline phosphatase, 4 elevated IgG and one elevated IgA. Three had low values of IgA, and all had normal values of IgM, IgD and IgE, and blood cells. In three patients, carbamazepine was withdrawn, whereupon the deposits disappeared in two and decreased in the third, who changed to another drug. The changes were quantitatively and qualitatively similar to those seen in systemic lupud erythematosus induced by these drugs.