A food allergy is when the immune system generates an adverse reaction to s specific proteins found in food. Symptoms of a food allergy range from moderate, such as tingling in the mouth and a skin rash, to life threatening, such as a severe swelling of the throat that makes it difficult to breath. A life threatening allergic reaction is known as anaphylaxis. 

Food allergies are common, but there are not as widespread as many people think. people most the times mistake food intolerance as to food allergy. this are two different things.

Most of the common causes of food allergy in children are EGGS, MILK, SOYA, WHEAT, PEANUTS

Most of the common causes of food allergy in adults are CRUSTACEANS (shellfish) such as crab, lobster, Prawns, tree nuts, such as walnuts, brazil nuts, almonds, and pistachios, peanuts, and fish

An allergy produce specific symptoms, such as the swelling of the lips, which usually develops within minutes of eating the food, while food intolerance produces more general symptoms, such as the indigestion and bloating, that can develop several hours after the food is eating. Only a tiny particle of food is needed to trigger a food allergy, whereas one would have to eat a large amount of food to trigger an intolerance. The symptoms of a food allergy can be life threatening, whereas the symptoms of food intolerance, unpleasant as they can be, are never immediately life threatening