Allergies are an increasingly common health concern for children. According to the American Academy of Allergy, Asthma and Immunology, the rate of allergies in the industrialized world has been rising steadily for 50 years. Today, as much as 40 percent of the population has some kind of allergy, including to foods, plants, insects, drugs, or other proteins. Allergies are more common in children with parents who also have allergies.
If your child is recommended for allergy testing, there are a few methods allergists use to identify specific allergies. The most common tests are skin prick tests and RAST tests.
Skin prick tests are performed by taking common allergens and diluting them. Then a small amount is inserted into the skin with a small prick or scratch with a needle. If the child is allergic to the substance, a reaction is usually seen within 15 minutes in the form of redness and a raised, itchy bump, also called a wheal.
In the case of food allergies, a positive skin test does not necessarily mean the child is allergic to the food but may indicate that further testing is needed. If your child has never had an obvious allergic reaction when eating that food, your doctor will likely perform a blood test to be sure there is a food allergy.
The most common blood test is a radioallergosorbent test, or RAST. This test uses radioactive markers to detect the levels of antibodies in the blood produced in response to the allergen. A RAST test is often performed in very young children to decrease the number of needlesticks needed for testing. In this test, blood is taken from your child’s vein.
Some doctors will perform a skin prick test and a RAST test to get a more clear picture of a child’s allergies if, for example, your child is having skin reactions, but it is not clear which foods are causing them. If allergies are found, your doctor will determine the best way to treat your child. This may involve allergy shots to help your child develop immunity to the allergens, antihistamines to reduce the reaction to the allergens, or elimination of certain foods from your child’s diet.
- Allergies are becoming more common worldwide.
- The most common allergy tests are the skin prick and the RAST test.
- Some doctors will perform both a skin prick and a RAST test, but both tests are 90 percent accurate.
- Once allergies are diagnosed, your doctor may recommend allergy shots, medications, or elimination of the offending allergen.