A food allergy is an exaggerated immune system response that occurs as a result of consuming specific foods. According to the Mayo Clinic, food allergies affect between 6 to 8 percent of children and approximately 4 percent of adults. It is important to note that food allergies differ from food intolerances, which are less serious.
Physiology of an Allergy
When someone with a food allergy consumes the food to which they are allergic, it triggers the body to create an antibody called immunoglobulin E, or IgE. In normal circumstances, this antibody is only produced in response to potentially harmful substances, such as bacteria or viruses. The next time the allergic person consumes that food, the antibody attacks it as a potentially harmful substance and triggers the release of a chemical substance called histamine. Histamine triggers a widespread inflammation response in an effort to protect the body from harm. This inflammation response causes the facial rash often associated with a food allergy.
Symptoms
One of the major symptoms of a food allergy is a rash on the face. The rash, which is usually composed of large, red welts called hives, may be itchy and irritating. The rash is usually accompanied by swelling around the eyes, tongue and mouth as well. Other symptoms include tingling in the mouth, wheezing, nasal congestion, abdominal pain, diarrhea, nausea and vomiting, according to the Mayo Clinic. If the food triggers a severe reaction allergic, called anaphylaxis, it can cause tightening of the airways, severe breathing difficulties, rapid pulse, lightheadedness and shock.
Treatment
A minor allergic reaction can be treated with over-the-counter antihistamines. Antihistamines block the action of histamine and help reduce facial rashes as well as the other symptoms of an allergic reaction. Anaphylaxis is initially treated with an emergency injection of epinephrine, also referred to as adrenaline. Because anaphylaxis is a life-threatening reaction, professional medical care should be sought.
Common Food Allergens
The most common food allergens in children include eggs, milk, peanuts, shellfish, soy, wheat and tree nuts. According to Medline Plus, most children outgrow their allergies to milk, egg, wheat and soy by the age of 5. Because of this, the most common food allergens in an adult include fish, peanuts, shellfish and tree nuts. Medline Plus notes that food additives, such as dyes or preservatives, may also cause an allergic reaction in some people.
Considerations
If you have a food allergy, it is important to play close attention to ingredient labels. Commercially produced foods often contain many of the most common food allergens. The Food and Drug Administration requires that a packaged food state whether it contains or was processed near any of these food allergens.
