Initial presentation of hemolytic uremic syndrome in a boy with systemic lupus erythematosus.

Associating systemic lupus erythematosus (SLE) with an initial presentation of hemolytic uremic syndrome (HUS) is rare. We report on a 13-year-old boy admitted to our hospital with an initial complaint of bilateral knee pain and multiple petechiae on both lower extremities. Diagnosis of atypical HUS was established according to the clinical triad of HUS without a veriotoxin-producing organism in his stool and the pathological finding compatible to thrombotic microangiopathy. In addition, his symptoms fulfilled the 1982 revised criteria for the classification of SLE. After methylprednisolone and cyclophosphamide pulse therapies, his laboratory findings and general condition improved. No plasmapheresis or any plasma infusion was required.