Food allergy is not the same as food intolerance.
But the two are frequently confused.
A classical food allergy (such as peanut or shellfish allergy) is usually characterised by an immediate and often severe reaction of the immune system to exposure to a specific food.
The symptoms of food allergy include sneezing, rashes, skin irritation, swelling, runny nose, fatigue, diarrhoea and vomiting. Normally symptoms occur within a few minutes of eating or coming in to contact with the offending food, although they can be delayed by up to two hours.
Food allergy is quite rare with only about 2.5% of the population being diagnosed with the condition. The most common instances of food allergy are to peanuts, tree nuts (almonds and brazils), eggs, milk, fish and shellfish.
When exposed to the source of food allergy the body makes specific antibodies (IgE) to ‘fight off’ the allergens found in these foods. When the food is next eaten it triggers an immune system response which results in the release of histamine and other naturally occurring chemicals in the body. Allergic reactions to food can vary considerably in their severity and some can be fatal.