A 64-year-old man visited our hospital on June 29, 1993. He had suffered from erythroderma for the past 18 months, and had been treated by a local physician. He had generalized erythema and severe pruritus, which had resisted anti-allergic medicines and topical corticosteroid. He needed continuous oral corticosteroid therapy (5 or 10 mg/day of prednisolone) for his pruritus. Towards the end of September 1993, during the therapy, multiple reddish-brown patches and nodules developed on his neck and cheeks. They gradually increased in size and number. The largest was 4 cm in diameter (Fig. 1). Superficial lymphadenopathy was not seen.
A biopsy specimen taken from a nodule on the neck revealed acanthosis of the epidermis and patchy infiltration, composed mainly of mature plasma cells in the upper dermis (Fig. 2). A small number of lymphocytes, histiocytes, and eosinophils were intermingled with them. Germinal center formations and obvious cellular atypia were not seen (Fig. 3). Immunohistochemical study showed that these plasma cells expressed immunoglobulin G (IgG), κ and λ light chains. Histologic examination of the erythrodermic skin on the back showed slight lymphocytic infiltration without atypia in the upper dermis. Almost all of the lymphocytes in both lesions reacted to T-cell marker UCHL1 (DAKO, Carpinteria, CA), and not to B-cell marker L-26 (DAKO). Laboratory examination detected normality in the complete blood cell count and in the peripheral blood smear, and no hypergammaglobulinemia. Serologic tests for syphilis showed a negative reaction. Titers of antibodies against spirochetes of Borrelia burgdorferi were not checked. Bence-Jones protein was not found in the urine. No abnormality was demonstrated by bone marrow puncture, bone x-ray, gastroenterologic endoscopy, and computed tomography of the head, chest, and abdomen.
The nodular lesions did not react to topical corticosteroid. Therapy with systemic prednisolone, 30 mg/day for a week, cured them, but could not improve the erythroderma. The patient continued to take oral prednisolone, 10 mg/day. Multiple reddish-brown nodules recurred on the same regions in March 1994. Histologic examination showed lymphohistiocytic cell infiltration without cellular atypia in the upper dermis. The number of plasma cells was small. Almost all of the lymphocytes were B cells, showing a positive reaction to B-cell marker L-26 and a negative reaction to T-cell markers UCHL1 and MT-1 (DAKO). These lesions disappeared spontaneously 6 months later.