At our Knoxville, Tennessee office we often receive questions about the nature of food allergies. Patients want to know what symptoms of a food allergy are, the causes, and what they can do to treat their food allergies.
It is estimated that between 40 and 50 million Americans have allergies, but only 1 to 2 percent of all adults are allergic to foods or food additives. Additionally, 8% of children under six have adverse reactions to ingested foods while only 2 to 5% of those children have a confirmed food allergy.Allergic reactions to foods typically begin with minutes to a few hours after eating the food. How often and how severe one experiences symptoms varies widely from one person to another. Mildly allergic persons may only suffer from a runny nose or sneezing, while highly allergic persons may experience severe and potentially life-threatening rations.
The most common symptoms of a food allergy involve the intestines or the skin. Symptoms presenting on the skin include rashes, like hives and eczema, while intestinal symptoms often include nausea, vomiting, stomach cramps, indigestion, and/or diarrhea.
Other symptoms that do not include the skin or intestines can include swelling of the tongue, lips, or throat; asthma, with coughing or wheezing; rhinitis, often including itchy, stuffy, runny nose and sneezing; loss of blood pressure; and, in rare cases, anaphylaxis, a severe, and possibly life-threatening, allergic reaction.
While it's possible that a patient experiencing these symptoms is having an allergic reaction to food, these symptoms may also be caused by a number of different diseases. Physicians will typically run tests to be sure that these symptoms are caused by a food allergy before a treatment plan can be discussed.
One such test is the skin test, where the physician will test for particular allergies by scratching the patient's skin with a toothpick like tool containing a tiny sample of the potential allergen. The patient's reaction to the skin test will help to determine if they are in fact allergic to the food in question or if their symptoms may be caused by something else.
If a patient has a food allergy it is the result of their body's immune system over-reacting to food proteins. Normally the immune system protects the body against allergic reactions; however, in the individual with a food allergy, the immune system produces increased amounts of the allergic antibody called immunoglobulin E (IgE).
When these antibodies combine with food proteins, histamine and other chemicals are released as part of the body's immune reaction. These chemicals can cause blood vessels to dilate, muscles to contract and skin to become red, itchy, and swollen. IgE antibodies are found all around the body from the skin to the lungs and the intestines.
Treatment for food allergies is typically focused on avoidance. However, even avoiding foods can't guarantee that one won't accidentally ingest it. So, it is important for those with food allergies to be aware and to have a plan should they accidentally ingest the food they are allergic to.
For those with mild allergies, oral antihistamines can be quite helpful. For those with severe reactions, keeping a shot of epinephrine handy, in the form of an EpiPen, for example, can make a major difference.
