[Severe combined immune defect. Presentation of exfoliative dermatitis with eosinophilia and lymphadenopathy]

We report on 9 infants with severe combined immunodeficiency (SCID), who additionally showed signs of Omenn syndrome with an exfoliative dermatopathy, alopecia, enlarged lymph nodes, a hepatomegalia and a striking blood eosinophilia. The immunological evaluation revealed the characteristic abnormalities of SCID with cellular and humoral immunodeficiency. All patients however had the unusual finding of mature T cells in the peripheral blood. By HLA typing these cells were noted to be of maternal origin in 5 patients. In the other 4 patients the T cells were of host origin. We asked for additional differences between both patient groups.Both patient groups were analyzed and compared with regard to case histories, clinical, laboratory and histopathological parameters.No clinical or laboratory differences could be detected. The histomorphologic analysis of patients with or without maternal T cells was identical. The skin biopsies showed dense cell infiltrations of lymphocytes, histiocytes and eosinophils, in the enlarged lymph nodes the latter two cell types predominated. Therefore the only difference between the 2 patient groups was the presence or absence of maternal T cells.Since the Omenn syndrome is found in association with maternal as well as patient derived T cells, we postulate that the peculiar symptoms of this syndrome are the result of a T cell induced inflammatory reaction, similar but not identical to a graft versus host reaction, occurring on the basis of an inborn SCID.