Abstract
Adult patients with immunoglobulin A vasculitis (IgAV) may present with more severe renal symptoms than pediatric patients. Renal biopsy may be difficult to perform in patients with a high risk of bleeding, leading to delayed diagnosis and treatment, and poor prognosis. However, administering steroids before the diagnosis is confirmed may be avoided because of the possibility of the disappearance of the pathological findings of IgAV. A 22-year-old Japanese male was admitted to our hospital with abdominal pain extending from the epigastric to the umbilical region for 10 days, watery diarrhea, and rapidly progressive renal dysfunction. On admission, palpable purpura was observed on both palms and the dorsum of the feet. Blood and urine tests revealed disseminated intravascular coagulation (DIC) and nephrotic syndrome. Although continuous hemodiafiltration was initiated, renal function did not improve. Skin and duodenal biopsies performed for suspected IgAV failed to confirm the diagnosis, and renal biopsy was difficult to perform because of the high risk of bleeding. Steroid pulse therapy was initiated before a definitive diagnosis was made, and DIC began to improve. A renal biopsy performed on the 13th day after starting steroid therapy showed mesangial cell proliferation, and immunofluorescence showed IgA and C3 deposition, confirming IgAV. Steroids were gradually tapered, dialysis was discontinued, and the patient was discharged on the 62nd day of hospitalization. In cases of IgAV with DIC, it is necessary to prioritize steroid administration over renal biopsy, and the biopsy can be performed after the bleeding tendency improves.