Expansion of large granular lymphocytes in psoriatic erythroderma. A case report

A psoriasis patient developed erythroderma after the withdrawal of a self-administered chronic topical glucocorticoid therapy. A marked expansion of cells with the morphological and phenotypic features of large granular lymphocytes was noticed in peripheral blood. Functional investigations revealed that these cells responded poorly to polyclonal activators and exhibited antibody-dependent cellular cytotoxicity and natural killer activity. Blood abnormalities completely subsided in about two months in the absence of any cytostatic therapy and coincided with the recovery from the erythroderma and the spreading of classical psoriatic plaque lesions. This excluded an underlying malignant process. This patient represents the first report of a previously undescribed immunological disorder in psoriatic erythroderma.