Idiopathic anaphylaxis.

Idiopathic anaphylaxis is a perplexing problem that accounts for approximately 30% to 60% of cases of anaphylaxis in ambulatory adults and perhaps 10% of cases in children. Advances in our knowledge of idiopathic anaphylaxis have occurred over the past decade with the elucidation of mast cell activating disorders and the discovery of episodes of anaphylaxis caused by galactose-alpha-1,3-galactose. Most patients do well because fatalities can usually be prevented with proper therapy, and many individuals, for reasons not understood, undergo spontaneous remission.