Food Allergy Testing May Save Your Life

Food allergies can pose a life-threatening risk, especially to young people, which is why food allergy testing is critical in early detection, diagnosis, treatment, and avoidance.

For those of us without food allergies, it can seem as though food allergies are no big deal, but each year, hundreds of people die from allergic reactions to foods.

Cow’s milk, eggs, peanuts, tree nuts (walnuts, pecans, hazelnuts, almonds, cashews, pistachios, and macadamia nuts), fish, shellfish, soybeans, and wheat (see our article on testing for celiac disease) are the most common food allergies.

People with food allergies must religiously check food labels and know exactly where their food comes from and what is in it.

Over time, some people can "outgrow" and begin to build a tolerance to some food allergens like cow's milk. However, peanuts, tree nuts, and shellfish allergens are often the causes of fatal reactions, and the person is unlikely to ever build up a tolerance to these.

This allergy emergency cabinet is a vital part of a school or clinic's first-aid gear

This allergy emergency cabinet is a vital part of a school or clinic's first-aid gear

Symptoms of a Food Allergy

Diagnosis of a food allergy can be hard, because the symptoms mimic so many other common health issues. Food allergies occur when a sensitive person eats, inhales, or comes into contact with even tiny amounts of certain foods.

Symptoms include reddening of the skin, hives, itchy skin, swollen lips or eyelids, coughing, vomiting, diarrhea, and life-threatening symptoms, like tightness of the throat, wheezing, and difficulty breathing.

For minor reactions, such as itchy skin or hives, a simple over the counter antihistamine like Benadryl can help.

For those with a fatal food allergy, they often carry epinephrine injections known as EpiPens. If the person comes in contact with their fatal food allergen, say peanuts, their throat can close completely and they may not be able to breathe.

Injecting epinephrine into their blood causes the throat muscles to relax and open up and increase blood circulation.

Getting Tested for a Food Allergy

If you have been experiencing any of the above mentioned symptoms after eating a certain food, you should consider scheduling an appointment for food allergy testing with an allergist.

The allergist will ask you to describe your symptoms, perform a physical exam, and possibly ask you to begin keeping a food diary. If this doesn't expose an obvious culprit, there a number of food allergy testing methods.

A skin prick test is often the first test done to help detect which foods you might be allergic to. In this test, a small amount of the possible food allergen is placed on the skin of your arm. Your skin is then pricked with a needle, to get a tiny amount of the substance beneath your skin.

If you are allergic to the particular food, you will develop a raised bump or a minor skin reaction within a few minutes. A positive reaction to this test isn't enough to confirm a food allergy, so you'll probably have to move on to blood testing.

A blood test can measure your immune system's response to particular foods by checking the amount of antibodies in your blood after exposure to certain foods. For this test, a blood sample is taken in your doctor's office and then sent to a laboratory, where they can safely expose your blood sample to possible allergenic foods.

Finally, the medical provider may wish to perform an oral food challenge test. During this test, done in the doctor's office for safety, you'll be given small, but increasing amounts of the suspected allergenic food. If you don't have a reaction during this test, you may be able to include this food in your diet again.

You may be asked to eliminate suspect foods for a week or two, and then add the food items back into your diet one at a time. This process can help link symptoms to specific foods.

However, this isn't a foolproof method. Psychological factors as well as physical factors can come into play. For example, if you think you're sensitive to a food, a response could be triggered that may not be a true allergic one. If you've had a severe reaction to a food in the past, this method may not be safe.

This is why you need to have your child tested for food allergies. Picture used courtesy of a Creative Commons license with the kind permission of Mandy Lackey and Flickr

This is why you need to have your child tested for food allergies. Picture used courtesy of a Creative Commons license with the kind permission of Mandy Lackey and Flickr

Treatment for Food Allergies

If food allergy testing results in a positive diagnosis, then you'll have to begin changing your diet to avoid the offending food.

Your doctor can teach you about reading food labels and finding information about the ingredients used at restaurants. Luckily, most food manufacturers will label their foods as containing things like eggs, dairy, peanuts, or tree nuts.

While there are no proven medical treatments other than avoidance of the food, there are experimental studies currently being conducted.

Desensitization (also called allergen immunotherapy) is a form of treatment in which the person is exposed to the allergenic food in small doses. These doses increase over time until the person is able to consume the food without reaction.

This is usually done orally, and sometimes, at home. This desensitization treatment can take 1-2 months or longer before the patient begins to see results. However, it isn’t guaranteed to work and studies are still being conducted.

If you are interested in this type of reduced food allergy testing, please consult your doctor first.

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