What is anaphylaxis?

The greatest danger from food allergy is anaphylaxis, also known as anaphylactic shock, a violent allergic reaction involving a number of parts of the body simultaneously. Like less serious reactions, anaphylaxis usually occurs after a person has already been exposed to an allergen, although it can appear to happen the first time a person eats a particular food.

Anaphylaxis is a severe allergic reaction that affects the entire body (systemic). It can occur within a few seconds or minutes after a person is exposed to a substance (allergen or antigen).

Symptoms and signs of a severe allergic reaction may include:

• Itching.
• Raised, red bumps on the skin (hives or wheals).
• Wheezing or difficulty breathing.
• Swelling, either in one area or over the entire body. Swelling is most serious when it involves the lips, tongue, mouth, or throat and interferes with breathing.
• Abdominal cramps.
• Low blood pressure, shock, and unconsciousness.

The sooner symptoms occur after exposure to the substance, the more severe the anaphylactic reaction is likely to be. An anaphylactic reaction may occur with the first exposure to an allergen, with every exposure, or after several exposures. An anaphylactic reaction can be life-threatening and is a medical emergency. Emergency care is always needed for an anaphylactic reaction.