Erythrodermic Psoriasis in a Man with Monoclonal B-cell Lymphocytosis

Erythroderma is characterized by erythema involving greater than 90% of the body surface area and may be caused by several etiologies, including erythrodermic psoriasis. Psoriasis is an autoimmune skin and systemic condition characterized by erythematous and scaly plaques. Monoclonal B-cell lymphocytosis is an asymptomatic hematological disorder diagnosed by elevated, small, clonal B-cell counts in the peripheral blood. The characteristics of a 71-year-old man with new onset of erythrodermic psoriasis and concurrent monoclonal B-cell lymphocytosis are presented. The simultaneous development of these two conditions raises the possibility that they may share a related pathogenesis.