Does your tongue itch when you eat shrimp or nuts? Does your stomach ache when you eat dairy products? If so, you may have food allergies…but, you might not. People often confuse food allergy with food intolerance. Food allergy affects the immune system and can range in reaction from mild to life-threatening even if a tiny amount of the offending food is ingested, the allergic person can have a severe reaction. Food intolerance, however, is typically related to inability to metabolize an ingredient and is usually dose specific meaning you can eat small amounts of the offending food without a reaction. The most common food allergies are milk, egg, peanut, tree nut (walnut, cashew, etc.), fish, shellfish (shrimp, crab, etc.), soy, and wheat.
Recent epidemiologic studies cited in the Journal of Allergy and Clinical Immunology suggest that nearly 4% of Americans are afflicted with food allergies, a prevalence much higher than appreciated in the past. Still, approximately 20% of the U.S. population alters their diet for a “perceived reaction,” which may or may not be food allergy.
If you suspect you have food allergy, the first thing you should do is see your doctor. You will likely be referred to an allergist or immunologist who specializes in such disorders. The allergist will likely perform a physical exam and ask for a detailed history. This information is extremely important. Without your help in discussing past symptoms and reactions, it is very difficult for the allergist to assess the potential culprits of the problem. Once your doctor has some ideas about what may be causing the symptoms, he/she will try to diagnose food allergy with some of the following measures:
*Having you keep a written record of your diet and when you have a reaction.
*Having you participate in an elimination diet, in which certain foods are taken completely out of the diet to see if it eliminates the symptoms.
*Performing a skin test, in which small amounts of a potential allergen are placed under the skin to see if it creates a local reaction.
*Performing a double-blind food challenge, in which capsules are ingested with specific food ingredients to see if a reaction occurs neither patient nor the person administering the test knows what is in the capsules (this eliminates psychological variables).
*Performing a blood test, which is sent to a laboratory to see if food-specific Immunoglobin- E (IgE) antibodies are present. These IgE antibodies suggest that your body thinks the food is a foreign agent and tries to fight it off, producing harmful chemicals such as histamine. Blood tests are typically expensive and used on those with severe reactions, since the other tests could result in a life-threatening reaction.
Common, mild symptoms of food allergy may include hives, swelling, itchy-red rash, eczema, itching or swelling of lips, cramps, nausea, vomiting, diarrhea, itchy-watery eyes, runny or stuffy nose, sneezing, coughing, or wheezing. More severe symptoms can include shortness of breath, difficulty swallowing, tightness of chest, itching or swelling of tongue or throat, change in voice, drop in blood pressure, fainting, and the most severe reaction anaphylactic shock. Anaphylactic shock can be fatal, either through swelling that shuts off the airway or through a dramatic drop in blood pressure.
If you are diagnosed with food allergy, it is important to learn how to manage your food allergy and to educate others. There is no cure for food allergy. The only way to manage food allergy is by strict avoidance of the offending food. To avoid the food you must read food labels and learn terminology that may be used on the label to identify said allergens; talk to your host, chef, or wait staff when dining away from home; educate others about cross-contamination and how to administer medications in an emergency, including antihistamine and epinephrine.
