Allergies/Food allergies

An allergy is an inappropriate response by the body's immune system to a substance that is not normally harmful. The immune system is a highly complex defense mechanism that helps us to fight infections. It does this by identifying foreign invaders and mobilizing the body's white blood cells to fight them. In some people, the immune system wrongly identifies a nontoxic substance as an invader, and the white blood cells overreact, creating more damage to the body than the invader. Thus, the allergic response becomes a disease in itself. Typical allergic responses are nasal congestion, coughing, wheezing, itching, shortness of breath, headache, fatigue, and hives and other skin rashes. The most common allergens are pollen, dust, certain metals (especially nickel), some cosmetics, lanolin, dust mites, animal hair, insect venom, some common drugs (such as benzoic acid and sulfur dioxide), animal dander, and chemicals found in soap, washing powder, cleaning supplies, and many other chemicals.

Foods also can provoke allergic reactions. Some of the most common allergenic foods are chocolate, dairy products, eggs, shellfish, strawberries, and wheat. There is a difference between food allergies and food intolerances. A person with a food intolerance is unable to digest and process that food correctly, usually due to a lack of a certain enzyme or enzymes. A food allergy, on the other hand, occurs when a person's immune system generates an antibody response to the ingested food. Food intolerance can lead to an allergy, however, if particles of undigested food manage to enter the bloodstream and cause a reaction.