Bullous dermatosis and myeloma. Monoclonal anticytoplasmic antibody activity

A case of a recurrent bullous eruption in a patient who had myeloma is reported. This eruption was differentiated from pemphigus and bullous pemphigoid by the histological and immunological findings. In addition, antibodies against the cytoplasm of basal cell layer cells in the human epidermis were detected in the patient's serum and in diseased skin. The myelomatous monoclonal protein and the antibody fixed on the cell cytoplasm had an identifical isotypical marker.