The common causes of anaphylaxis include foods such as peanuts, tree nuts, milk, eggs, shellfish, fish and sesame seeds, although many other foods have also been known to trigger anaphylaxis. Some people can react to even tiny amounts of the food.
Non-food causes include wasp or bee stings, natural latex (rubber), and certain drugs such as antibiotics. In some people exercise can trigger a serious allergic reaction – either on its own or in combination with other factors such as food or drugs (for example, aspirin).
Sometimes the cause of the reaction is not found. This is called “idiopathic anaphylaxis” (cause unknown). Read our Idiopathic Anaphylaxis factsheet for more information.