ACUTE ERYTHRODERMA AS AN EXCLUSION CRITERION FOR IDIOPATHIC CD4(-LYMPHOCYTOPENIA() T)

Background: Idiopathic CD4(+) T lymphocytopenia is defined as a CD4(+) T lymphocytopenia of less than 0.3X10(9)/L that is not associated wit h human immunodeficiency virus, other immunodeficiency, or immunosuppr essive therapy. The associated clinical course and laboratory findings are variable. We describe a subset of patients whose peripheral CD4() T-lymphocytopenia was transient, and suggest a pathomechanism for th is phenomenon. Observations: We describe three patients with cutaneous T-cell lymphoma, atopic dermatitis, or psoriasis in whom acute erythr oderma was concomitant with a peripheral CD4(+) T lymphocytopenia that normalized after resolution of the erythroderma. Immunoperoxidase sta ining of skin biopsy specimens and quantitative estimation of CD4(+) T lymphocytes in the cutaneous and peripheral blood compartments demons trated that the peripheral CD4(+) T lymphocytopenia in these cases mos t probably resulted from sequestration of CD4(+) T lymphocytes in the skin. The skin of an erythrodermic patient appears capable of sequeste ring 10(10) to 10(11) CD4(+) T lymphocytes, whereas the peripheral blo od compartment contains in the range of 10(9) CD4(+) T lymphocytes. Co nclusions: We propose that CD4(+) T lymphocytopenia can occur as a res ult of acute erythroderma of multiple causes and that acute erythroder ma associated with transient CD4(+) T lymphocytopenia be considered as an exclusion criterion for idiopathic peripheral blood CD4(+) T lymph ocytopenia.