SummaryThe author relates a clinical case of periarteritis nodosa occuring by a thirty old woman.The disease began two years ago as a common bronchitis. Then occured typical asthma crisis and a loss of weight of fifty eight pounds.The asthma disappeared, followed by a short period of ulcerous colitis.Thereafter the patient presented a drop of the right hand with muscular atrophy.Finally a complete left hemiplegy occured.The evolution was practically apyretic, but was accompanied by an eosinophilia of nearly 60 %.There was no subcutaneous periarterial nodulars. Therefore the anatomical diagnosis was not established.After classical notions concerning periarteritis nodosa, the author reports more recent opinions which consider the disease as a severe manifestation of allergy.