ABSTRACT
Relapsing hemolytic and uremic syndrome is infrequent in pediatric patients. The case of an infant who had HUS at 11 months of age and subsequently developed two relapses at 3 years and 3 1/2 years of age is reported. Outcome of the first episode was favorable, with no elements suggesting an increased risk for subsequent relapses. Conversely, the second and third episodes were followed by gradual deterioration of renal function and persistence of severe arterial hypertension. To clarify the epidemiology, clinical manifestations, histology, and outcome of HUS, the 24 pediatric cases of relapsing HUS reported in the English-language medical literature were reviewed. In this group, mean age at onset was 4 years 1 month (range 4 months-9 years) and number of relapses ranged from 1 to 14. Evidence of microangiopathy was the most common histologic finding (15/22) but non-specific lesions were seen in some instances. Opinions vary as to the prognosis of relapsing HUS; our case suggests that relapses are of adverse prognostic significance.
