Results of studies from the Mayo Clinic indicates that around two percent of the adult population in the United States suffer from some form of food allergy. In addition, food allergies in children account for another 6 percent. While those percentages may look low,  with a total population of more than three hundred million in the America that translates to six million and 18 million individuals, respectively.

Like other allergic reactions, a food allergy happens when the immune system overreacts to an allergen. Common food allergens include, but are not limited to, products that are dairy based such as yoghurt, seafood, shellfish, peanuts and eggs.

Responding to contact or consumption, the body releases an antibody by the name of IgE (immunoglobulin E) because it views the food not as nutrition, but a foreign invader. The allergy symptoms are produced as a result of the release of histamine, prostaglandins and various other substances which are stimulated by the antibodies.

Food allergy symptoms are inclined to be more extensive than those that mark other allergies. These include the possibility of watery eyes and congestion of the nasal passages. Nevertheless, they are typically accompanied with or even overtaken by such things as swelling up of the lips, pharynx or tongue, urticaria or skin hives (itchy red swellings that form on the surface of the skin), nausea, wheezing and even pain in the abdomen.

Anaphylactic shock can happen in more severe cases. Anaphylaxis is a systemic (overall body) allergic reaction. It involves some serious symptoms such as dizziness, constricted airways resulting in breathing difficulities and a dramatic drop in blood pressure. It comes on quickly and if not treated immediately, can sometimes cause death. As many as 200 deaths per year in the U.S are attributed to anaphylaxis.

Sometimes, allergic reactions to food are localized. For example, some people will experience a tingling sensation in their mouth after eating fresh fruit or vegetables. The cause is thought to be proteins similar to those found in ragweed pollen.

Professional diagnosis by an allergist is the only way to find out if an individual suffers from food intolerance or a food allergy.

To  ascertain if a person has an allergy to certain foods, the allergist will carry out an allergy skin prick test. The doctor takes a minute quantity of the suspect substance and exposes the person to it by introducing a small quantity under the skin with a lancet. The area of skin is then monitored for approximately half an hour to discover if any itchiness or swelling takes place as a consequence of any response to the suspect substance.

In some cases, a blood test might be warranted. This measures the amount of IgE produced in response to consuming the suspicious food. But, this test it is not always conclusive.

An example of where the symptoms are similar but not the same as an allergy is lactose intolerance. This is caused by the genetic deficiency of a digestive enzyme that is needed by the body to process cows milk safely.

Eliminating the problematic food from the diet and environment is the optimum and best line of defense. Even though it is maybe a simplistic view, an individual who has an allergy to egg based products should avoid ingesting such foods. The same applies to anybody that is allergic to peanuts or products that contain traces of them.

Because there is no known cure for food allergies, avoidance is the best medicine. However, it is not so easy to avoid some substances, in spite of your best efforts and in that circumstance, symptom relief is available in the form of antihistamines. It's also good to have on hand an EpiPen or similar device that lets allergy sufferers to inject a small quantity of ephinephrine in an energency situation. A serious attack of anaphylaxis can be kept at bay until professional medical help can be found.