Omenn's syndrome and related combined immunodeficiency syndromes: diagnostic considerations in infants with persistent erythroderma and failure to thrive.

A 4-month-old male infant had a 2-month history of an exfoliative erythroderma and alopecia. Recurrent mucosal infections, diffuse lymphadenopathy, hepatosplenomegaly, lymphocytosis and eosinophilia, anemia, and failure to thrive later developed. Investigation revealed a combined immunodeficiency with T cells of an unusual phenotype in his peripheral blood, skin, and lymph nodes. Our patient's clinical manifestations most closely resemble Omenn's syndrome, a rare form of autosomal recessive combined immunodeficiency.