Henoch-Schönlein syndrome and IgA nephropathy: a case report suggesting a common pathogenesis.

An 8-year-old Caucasian male presented with two episodes of gross hematuria but was otherwise asymptomatic. Serum IgA levels were markedly elevated and a renal biopsy showed mesangial proliferative glomerulonephritis with immunofluorescent and electron microscopy findings consistent with IgA nephropathy (IgAN). Two years later he developed abdominal pain, rectal bleeding, gross hematuria and a classic purpuric rash of Henoch-Schönlein syndrome (HSS). Serum IgA levels continued to be elevated and 3 years later in follow-up he is clinically well. These observations support the concept that HSS and IgAN are variants of the same process. The reverse situation has been reported in a 15-year-old female who developed HSS at 4 years of age and IgAN at age 15 years.