A rare, frightening and poorly understood disease.

Anaphylaxis is a fast-moving, generalized hypersensitivity (exaggerated bodily response to some substance) reaction that can lead to death either by circulatory collapse (shock) or by obstruction of a person's airway.

Most people associate anaphylaxis with allergies, but anaphylaxis is not always caused by a traditional allergic reaction. Some individuals who have no allergies whatsoever can still undergo anaphylaxis.

Stop for a moment and think about that: People who do not test positive for any allergen (substance that causes an allergic or hypersensitive response) and who have completely normal levels of immunoglobulin E (which the body produces when developing allergies), can have life-threatening attacks of anaphylaxis.

And other people can undergo anaphylaxis even though the reaction does not seem warranted given their mild allergies.

In both cases, when a person repeatedly has anaphylaxis that cannot be explained as a traditional allergic reaction, and when many other diseases and conditions have been ruled out, the person is said to have idiopathic anaphylaxis (IA).

Most people — and even some doctors — are unfamiliar with IA, and you may hear misinformation from both medical personnel and the general public. That is why this web site exists. Our goal is to create a reliable, well-documented source for the latest and most complete information available. ◊

This site is very much a work-in-progress. There are topics within both the IA and Anaphylaxis sections still To Be Done, which are shown on the left in yellow. The Articles, FAQs, Blog, About Us, References, and Links sections are mostly complete. Any and all feedback, reports of errors, typos, bum links, etc., are much appreciated. Please send them to Candace.