A case of lupus nephritis showing rectal erosion with cytomegalovirus infection

A case of lupus nephritis showing rectal erosion with cytomegalovirus infection is described. The patient revealed nephrotic syndrome. She complained of skin ulcer with livedo reticularis on the right breast, purpura with thrombocytopenia, hepatic dysfunction, and bloody stool. Renal biopsy demonstrated diffuse proliferative lupus nephritis with prominent wire loops. Intestinal fiberscopy showed rectal erosion which was a cause of bloody stool, and rectal biopsy revealed cytomegalic inclusions characteristic of cytomegalovirus infection. Immunosuppression due to combined therapy with prednisolone and mizoribine could have led to reactivation of latent cytomegalovirus infection, resulting in the rectal erosion with bloody stool.