A 10-year-old girl with IgA nephropathy who 5 years later developed the characteristic features of Henoch-Schönlein purpura nephritis.

We report a patient who developed Henoch-Schönlein purpura (HSP) 5 years after she presented with immunoglobulin A nephropathy (IgAN). A 10-year-old Japanese female was identified with proteinuria and hematuria by a school urinary screening. The first renal biopsy showed mesangial proliferative glomerulonephritis with immunofluorescent findings consistent with IgAN. She was treated with prednisolone, warfarin, and dilazep dihydrochloride, and the proteinuria and hematuria disappeared 4 months after the onset of treatment. Five years later she developed abdominal pain, gross hematuria and a classic purpuric rash of HSP after acute pharyngitis. The second renal biopsy showed diffuse mesangial proliferation with cellular crescent formation, and the patient was treated with methylprednisolone pulse therapy, prednisolone and mizoribine, resulting in a gradual decrease in urinary protein excretion. Our patient is unusual in that she developed Henoch-Schönlein purpura nephritis 5 years after clinical and biopsy evidence of IgAN, which suggests that IgAN and HSP are different clinical manifestations of the same disease, probably sharing a common pathogenesis.