Polyarteritis nodosa and congenital pyloric hypertrophy in a 3-month-old infant.

A case of polyarteritis nodosa in the first year of life with the clinical picture dominated by pyrexia, an initial upper respiratory element, episodes of tachycardia, and sudden death three weeks after the onset is described. The necropsy showed evidence of polyarteritis nodosa, myocarditis, and valvulitis as well as congenital pyloric hypertrophy. Clinical manifestations of the latter had preceded the final illness and the two diseases were not thought to be related. The previous 19 cases reported in the first year of life are reviewed, and support is given for the concept that at this age a rash, pyrexia, upper respiratory manifestations, and progressive heart failure or sudden death are characteristic clinical manifestations and that the heart is often the site of the major lesions at necropsy. The possible role of hypersensitivity is discussed. There was no evidence for it in the present case.