We report on an expanding series of cases of idiopathic anaphylaxis (IA) with development of a classification, therapeutic regimens, and control of disease and induction of remission. Simultaneously, a growing series of cases referred for diagnosis and management of IA do not have IA. These cases, which approximate 10% of our series of IA cases, present serious time-consuming diagnostic problems for physicians. We present a series of nine cases of this type of nonorganic disease and describe the presenting symptoms, failure to document clinical abnormalities, and the lack of a response to a regimen shown to be effective in altering the course of true IA. The classification of IA has been expanded to include IA variants for patients in whom the symptoms complex varies significantly from other types of IA. Diagnostic suggestions and the problems of management are reviewed.