Allergies affect children of all age--from newborns to older children. If you suspect your child has an allergy, it's best to seek medical advice. Your infant may have a food allergy or he may be allergic to chemicals, medicines or environmental allergens. You health care provider will take a complete medical history and then recommend one or more tests to either confirm or eliminate suspected allergens.
Skin Prick Test
The skin prick test is one of the most common allergy tests performed, and it's also highly accurate. The skin prick test can be performed on infants as young as four months of age. The test involves your health care provider either scratching or pricking your infant's skin with a lancet containing a solution with a possible allergen. The test is usually carried out on an infant's back so they can't see what's going on. A positive result is indicated by a red, itchy raised bump (known as a wheal) on the skin's surface after the solution is allowed to enter the epidermis. The larger the size of the wheal, the more allergic your infant is to the allergen.
Blood Test
The Radio Allergo Sorbent Test (RAST) is a blood test that's used to identify approximately 400 different allergens. The blood test measures the levels of an antibody, immunoglobulin E (IgE) in your infant's blood. Allergy sufferers have higher IgE levels in their blood. Available tests include a respiratory allergy screening test, a seafood screening test, a food allergy screening test and a nut allergy screening test. A positive result is indicated if the levels of specific IgE antibodies are four times higher than normal for a particular allergen.
Allergen Provocation Test
The allergen provocation test is used to test a suspected aero-allergy. Infants are tested to determine if they have an allergy to pollen, animal dander, dust mites or mold extract. During the test, the suspected aero-allergen is introduced into either the eyes, nose or lungs. The medical staff observes whether the allergen has provoked an allergic reaction.
Food Challenge Test
The food challenge test is also known as the Double Blind Placebo-Controlled Food Challenge Test (DBPCFC). It is performed by a doctor or certified allergist in an allergy clinic or hospital where resuscitation equipment is available. The DBPCFC is used to determine whether your infant is allergic to a specific food allergen. During the test the suspected food allergen is disguised in either a sample of food, broth or capsule. Neither the patient nor the food allergist are aware of which samples contain the suspected food allergen. The patient is given the sample and any reactions are carefully observed and recorded. Although it's time consuming and expensive, the DBPCFC is one of the most effective tests in detecting food allergies.
Patch Test
Symptoms of an allergic reaction aren't always instantaneous. Infants sometime show delayed reactions to contact allergens like rubber, nickel, preservatives, skin medications and lanolin. In a patch test, small samples containing the suspected allergens are taped to the skin, usually the back, and covered with special aluminum disks. The patches are left on for 48 hours. After another 24 hours have elapsed, the skin is carefully observed for the appearance of blisters or redness.
