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How do you test for allergies?


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2015-08-17 17:07:46
2015-08-17 17:07:46

Blood tests can be done to look for elevated white blood cell counts, level of particular antibodies, or for reactions with allergen extracts. Blood tests are not 100% reliable and, to get good results, must be done by highly trained lab technicians. Some doctors use these tests, while others prefer not to. The patient will need to have blood drawn for this, which may be a drawback for testing children.

"Scratch" test involves scratching the skin, then dropping liquid allergen on the scratch. It's done on the arm or (for very small children) the back. It seems to hurt a little, but may be scary to little ones. Each slate has up to 6 tests, plus positive (histamine) and negative controls. Bumps/weals for a reaction appear immediately or several minutes later. The patient must remain in the office in case of severe reaction (rare).

A positive reaction is reliable, but a negative reaction may not be; that is, you may be allergic but not react. Skin tests are more reliable for airborne allergies than for foods.

Elimination diets are the only guaranteed way to determine food allergies. The patient goes on a *very* restricted diet, composed only of foods that rarely cause allergy problems. A new food is added each week. If the patient does not have any allergic symptoms to the new food during that week, then it is not considered an allergen. A new food can be added the next week. If the patient has a reaction to the food, the food is considered an allergen and removed from the diet. The patient then goes back to the previous diet until all symptoms are gone for three days; then a new food can be added. This is a very slow way to build up much of a varied diet, but it is certain. In adding foods, you must be careful that it is only one food that is being added. This means no processed foods (may have additives), no pre-packaged foods (may have additives), no seasonings (except salt), etc. This can be very difficult to follow if you eat out for any meals. Generally safe, non-allergenic foods usually include apricots, peaches, pears, beets, sweet potato, rice, distilled or spring water, cane sugar, salt, tapioca, olive oil, lamb and chicken. (Not very exciting..) Your doctor may give a different list, based on your personal situation. It is fairly easy to put a young baby on an elimination diet, but it gets harder as the child gets older. For very young children, this should only be done under a doctor's supervision (unless the child is exclusively breastfed) to ensure a balanced diet.

If the original allergic reaction was moderate or worse, you must challenge test when adding a suspected new food. That is, you start with a pea-sized piece. If no reaction, on day 2 try a 3-pea-sized piece. No reaction, day 3 try a 9-pea-sized piece. Discuss this with your doctor. ALWAYS get instructions beforehand (and medicine, if necessary) on what to do for a severe reaction. If the original reaction was severe, your doctor will want to do this at his office or at the hospital.


Related Questions

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The skin patch test is done to test for allergies

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The most common test for any food alergy is the skin test. However, there is a way that doctors can test for allergies by a simple blood draw. This test is called Elisa and it will detect most food allergies.

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I'm not sure of a specific test to take; however, if you feel that you are having seasonal allergies try consulting a doctor. If you don;t have time for that perhaps consider buying a bottle of Zyrtec ( no prescription needed) and seeing if that helps with your probable allergies. Good luck!

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Physiological reactions to chemicals, including those associated with nutrition and allergies , may also be evaluated using AK.

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You have to call your doctor and have them refer you to an allergist. Then discuss what you want from him. Usually in adults they do the blood test.

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