Food allergies are very common affecting one in every 13 children. Negative reactions occur when a specific food protein is detected and attacked by the immune system as if it was a harmful foreign invader. Food allergies should not be confused with food intolerances, which are the inability or difficulty digesting a particular food.
The severity of a food allergy depends on the number of protein-specific IgE antibodies in the blood. Often times the longer the history of the allergy, the more food-specific IgE will be present. The skin test and blood test measure food-specific IgE to determine the severity of an allergy.
Diagnosing Food Allergies
Anyone can develop a food allergy during any stage in life. Maybe you grew up eating eggs but at age 24 you start noticing symptoms after breakfast. You started to notice stomach cramps after breakfast some mornings but you haven’t changed your routine for years. Food allergies can be tricky to catch and diagnose because even symptoms can be different from day to day. Today you may have cramps but tomorrow you may notice:
- Vomiting or stomach pains
- Shortness of breath
- Hives or a redness of the skin (Especially around the mouth)
- A runny nose or nasal congestion
- Swelling of the mouth and tongue
- Turning blue
With various symptoms that are prone to change it can be very difficult to diagnose a food allergy. If you do suspect an allergy, try the elimination test!
The Elimination Test
Food allergies can be hard to catch especially if the symptoms are subtle and change from time to time. Eliminating and then reintroducing the food into your diet can be one of the best tests to figure out if you truly have a mild allergy.
To conduct the test, simply remove a suspect food from your diet for two to three weeks and note the changes in symptoms if any. After the elimination phase, reintroduce the food into your diet slowly. Each day eat more and more of the food unless you notice a reaction. If nothing changes than you probably do not have an allergy. If the symptoms come back or get worse during the re-introductory phase, you most likely have a food allergy.
While this test can be slow and often tedious, it is usually one of the best ways to test for a food allergy. Often allergists will recommend a similair elimination test after they have done skin or blood testing! If you don’t know which foods may be giving you trouble, below are some of the most common foods people have reactions to.
- Tree nuts
- Fish and Shellfish.
Should You Test?
If you still have a food allergy suspicion after the elimination test, skin or blood testing may be able to put the suspicion to rest. Before testing it is good to have specific food allergy suspicions. For example, you have done the elimination test and found that eggs and milk may be causing problems but you are not 100% sure, a skin test may be able to show what you are definitely not allergic to. On the other hand, simply testing everything you eat on a daily basis may not be a good idea. While foods tests can be helpful in ruling out foods you are NOT allergic to, false positives are prominent and don’t always indicate a food allergy.
Skin testing one of the most common types of food allergy testing and provides results within 15-30 min. This test is typically conducted on the arm or back. The allergist will prick the skin with a small probe to initiate the reaction. A solution is then introduced to the skin containing the food at question. If a mosquito bite like reaction appears on the skin, the test is considered positive and you may be allergic.
Before jumping to concussions, false positives are prominent and should be investigated further. In fact, over 50% of skin prick tests will yield a false positive!
One reason for false positives is that sometimes the body will react to undigested food particles. Once eaten, foods are digested and broken down before entering the body. A skin test may show a positive reaction to eggs, although after digestion, the protein is undetected by the body.
Testing positive for a food may also be a result of your body detecting proteins that are similar among foods but do not cause an allergic reaction in the body. For example, you may test positive for peas although you are actually allergic to peanuts. Because both foods are in the legume family, their proteins may look similar. You may be able to eat peas with no complications although eating peanuts will result in a rash.
Blood testing is most common among patients who have a skin condition or who are using antihistamines. A blood test measures the amount of food-specific IgE to determine if you have a food allergy. Like skin testing, blood testing is not considered 100% accurate. Unless you have a skin condition or are taking antihistamines regularly, opt for the skin test.
Bonus Tip – The Solution
Unfortunately, there is no known cure for food allergies. If you find a food that you react to, the best thing to do is to eliminate the food from your diet. If you happen to be MILDLY allergic to your favorite food, try reintroducing the food into your diet after a year or so. Sometimes food allergies will cure themselves! If you have a severe allergic reaction to any food, it is best to stay away from the food indefinitely.