An unexpected diagnostic course of systemic lupus erythematosus.

Thrombotic microangiopathy (TM), especially thrombotic thrombocytopenic purpura (TTP) is described in systemic lupus erythematosus (SLE) as a severe hematological involvement. However hemolytic uremic syndrome (HUS) is seen less frequently in SLE, particularly as an initial presentation. Here we present a 15-year old boy presenting with gross hematuria, decreased urinary output and petechial lesions. He was diagnosed as atypical HUS according to the classical triad of TM, along with observation of hypocomplementemia and negative stool cultures. In addition, his symptoms fulfilled the 2012 revised criteria for the classification of SLE. He was treated with plasma infusions and methylprednisolone/prednisone. At follow up his laboratory findings and general condition improved and no relapse was seen.