what is a food allergy?
A food allergy is an immune system reaction to a protein in a particular food that is consumed. Within a few minutes of ingestion, symptoms such as, skin irritations, swelling, and difficulty with breathing can occur. Food allergies are most common in children and toddlers, and it is possible that they may grow out of allergies to dairy, wheat, eggs and soy. Allergies to seafood, peanuts, and tree-nuts are usually long-term.
Other food allergies include sesame seed, poppy seed, corn, MSG, sulfites, and animal derived ingredients (these are ingredients that contain amounts of either meat, fish, dairy, or any ‘parts” from any animal, and the food label uses a variety of terms to describe these ingredients without a clear precise description).
other conditions that are mistaken for food allergies
The immune system in not involved in a food intolerance. An intolerance occurs when the body does not make enough of an enzyme in that food and therefore has difficulty digesting the food. Symptoms are slightly different and less severe. For example, a lactose intolerance is when the body does not make enough lactase enzyme, which is the component that helps digest the lactose (lactose is the sugar in dairy). The symptoms may include stomach cramps, bloating, diarrhea, and gas. A food intolerance is not life-threatening, and can be managed by either avoiding that food or taking a supplement with the deficient enzyme.
Another term for an allergy or intolerance.
Avoiding certain foods based on personal preference or psychological reasons.
When food is consumed the immune system treats a particular protein in that food as a threat to the body. Immunoglobulin E, or IgE, is an antibody that is produced by the body to attack the food protein (the antigen). Once the antibodies have contact with the antigen it signals an attack on the protein by releasing histamine and other chemicals. These chemicals cause the allergic symptoms. Each type of food has its own proteins. A person may become allergic to one protein or more than one.
- Wheezing, difficulty breathing
- Runny nose, congestion
- Swelling of the lips, eyes, face, tongue and/or throat
- Mouth tingles or is itchy
- Skin rash (note: eczema is a common skin condition often associated with food allergies, see your doctor for proper diagnosis)
- Loose stools
- Dizziness, lightheadedness
- Anaphylaxis (can occur in some severe cases) Anaphylaxis is when the throat swells, making breathing difficult because the airways constrict. Other symptoms may include a rapid pulse, dizziness, shock, and lightheadedness. This is life threatening and needs to be treated immediately by a clinician.
how to test and diagnose
Food Diary: If you think you have a food allergy track your diet and symptoms. Keep a diary of the foods you are eating and what signs and symptoms you are experiencing after eating those foods.
Elimination Diet: Remove the suspected allergen from your diet for 2-3 weeks. After 2-3 weeks gradually reintroduce those foods into your diet and see how your body reacts. You can use www.foodfacts.com as a guide for ingredients to avoid or substitutions. If your symptoms are relieved during the time the food is eliminated, you may be allergic to that food. See your doctor for proper diagnosis.
Skin Test: See your doctor or an allergist and get tested. Your doctor can perform a skin test. A tiny amount of food(s) that can possibly cause an allergy is applied to your skin. Your skin is then pricked to allow that amount of food to get below the skins surface to see if you have a reaction. If you are allergic a rash may develop or another type of reaction can occur on the area that the food was applied.
Blood Test: A blood test can determine the amount of immunoglobulin E (IgE) antibodies in your blood. Your blood is sent to a lab where they test foods with your blood to see if a particular food causes you to have high amounts of IgE. If you have high amounts of IgE then you are allergic to that food.
how to manage
- Avoidance is the only way to prevent symptoms from a food allergy. Be careful to read food labels to avoid your allergen and educate yourself on the names of the ingredients that may indicate your allergen is present. There are many substitutions that you can use for the foods you need to avoid.
- Wear a Medical Alert bracelet to alert others to be aware of your allergy in case there is an emergency.
- Be sure to tell family, friends, co-workers, teachers etc. of your allergy if there should be an emergency.
- Carry an epinephrine autoinjector as directed by your doctor. If you have a severe allergy, and in the event that anaphylaxis occurs, this is advisable. This requires a prescription from your doctor. Your doctor may also prescribe other antihistamines. Antihistamines may be used; however, it is not as effective.