Long term renal prognosis of Henoch-Schönlein purpura in an unselected childhood population.

All 270 patients presenting with Henoch-Schönlein Purpura over a 13-year period from a total childhood population of 155,000 were studied. This is an incidence of 13.5/100,000 children per year. Fifty-five (20%) were found to have initial evidence of renal involvement, and were re-examined at a mean of 8.3 years later. The 37 with isolated haematuria or haematuria with mild proteinuria (67%) recovered completely. Eighteen (33%) had nephritic or combined nephritic/nephrotic features, of these one died in the acute phase of the illness, only three others have persistent urinary abnormalities but have no biochemical evidence of renal impairment and only minor histological changes. The overall prognosis in this unselected population is therefore good with a mortality less than 1% overall and low long term morbidity of 1.1%. This study indicates a more optimistic outcome in this condition than the majority of published estimates based on more selected groups of patients.