This is because it could be that there may be more than one thing you are allergic to. Sometimes, the doctor will diagnose the condition as idiopathic, but then later on you may realise that you only get anaphylactic reactions after eating certain foods or after being stung by something. The doctor may also ask you to undertake allergy testing and physical examinations. In cases of idiopathic anaphylaxis, it is essential that you always carry around your prescribed auto-injector, as you cannot always stay away from allergens. Many people with idiopathic anaphylaxis see a decrease in reactions as their life goes on, again, however, it is unclear why this is.
For more details, we have an Anaphylaxis video online course at www.proanaphylaxis.co.uk