Anaphylaxis is a rare but potentially fatal condition in which several different parts of the body experience allergic reactions. These may include itching, hives, swelling of the throat, difficulty breathing, lower blood pressure and unconsciousness. Symptoms usually appear rapidly, sometimes within minutes of exposure to the allergen, and can be life threatening. Immediate medical attention is necessary when anaphylaxis occurs. Of all the individuals who have any type of food sensitivity, most have food intolerances.
Fewer people have true food allergy involving the immune system.
Other reactions to foods are called food intolerance and food idiosyncrasy. Food intolerance and food idiosyncrasy reactions are generally localized, temporary, and rarely life threatening, whereas food allergy can cause life-threatening reactions. Lactose intolerance is an example of food intolerance. It occurs when a person lacks an enzyme needed to digest milk sugar. If a person who is lactose intolerant eats milk products, they may experience symptoms such as gas, bloating and abdominal pain.