Monoclonal gammopathy in scleredema. Observations in three cases.

A monoclonal gammopathy was observed in three patients with long-term and widespread scleredema (Buschke's disease). There was no evidence of multiple myeloma in any patient. Deposition of monoclonal immunoglobulins in the skin was not detected by direct immunofluorescence microscopy. In contrast to scleromyxedema (lichen myxedematosus), from which scleredema can be distinguished clinically and histologically, the monoclonal immunoglobulins in two cases were of IgG2-kappa and IgG3-kappa type. Only one of the three patients had IgG1-lambda paraproteinemia, which is frequently seen in scleromyxedema. Our findings suggest that diffuse scleredema may be characterized by paraproteinemia but that the possible role of monoclonal immunoglobulins in the pathogenesis of this disease has yet to be resolved.