Malignant idiopathic anaphylaxis: three additional cases and extended evaluation.

Northwestern University's Division of Allergy and Immunology (NUAI) has evaluated and treated 225 patients with idiopathic anaphylaxis (IA) over a period of 16 years. Four patients have been identified with malignant IA. The term "malignant" is used to identify those patients with the most severe form of IA that is resistant to standard therapy. The diagnosis of malignant IA is made in patients with IA whose controlling oral corticosteroid dose was not able to be reduced below 60 mg of prednisone (or its equivalent) every other day or 20 mg of prednisone (or its equivalent) every day without an exacerbation of IA. Presented here is the long-term evaluation of one patient as well as three additional patients with malignant IA managed by our service. At the time of this report we have had no deaths due to IA in patients treated with pharmacologic regimen.