Do the words “allergy testing” bring to mind images of multiple injections with big, painful needles?
That type of allergy testing is a thing of the past, said Dr. Farhat Kokan, a Marshfield Clinic Health System allergist. Today’s skin tests are done with little plastic devices that make small scratches on the skin. The test feels like a series of pokes that hurt much less than the old way of testing.
Parents and kids don’t need to feel nervous that testing for common environmental, food and venom allergies is going to be painful. If your child has a stuffy nose that doesn’t go away, has allergy symptoms after spending time at a family member’s or friend’s house, or you can’t figure out what’s causing a recurring rash, ask your pediatrician about allergy testing.
What to expect during allergy testing
You will get instructions to stop giving your child antihistamines like Zyrtec and Claritin five to seven days before testing. These medicines can interfere with test results.
The doctor will listen to your child’s lungs before testing on the day of the appointment. If your child is having trouble breathing because of asthma, the doctor won’t run tests that might make allergic asthma symptoms worse. If it’s safe to keep going, the doctor will explain how allergy skin tests work.
I might tell young children that I’m doing a test to find out if dogs and cats make them sneeze,” Kokan said.
A small plastic device that looks like a toothpick is dipped in a liquid allergen and used to make a small scratch on the child’s upper back. The doctor may show the child how it works using a clean device on the back of the parent’s hand. Parents can distract their kids with books or toys while the test is happening.
Skin testing works for many types of allergies, and most of the time, the process doesn’t involve needles. However, the doctor may need to take a blood sample or inject a small amount of allergen under the skin using a tiny needle to test for certain allergies. Dermatologists sometimes place patches with allergens on the skin to check for contact allergies to metals.
Results during the office visit
Making the scratches with different allergens doesn’t take long, but you’ll have to wait about 20 minutes to find out which ones cause reactions.
A small area of swelling (called a wheal) surrounded by some redness (called a flare) means your child has an allergy. The doctor will measure the size of the wheal and the flare. Larger patches mean the allergy is more intense.
“The reactions can feel uncomfortable if the child has a lot of allergies,” Kokan said. “The swelling and redness should go away after a few hours. We can give the child antihistamines to stop the itching.”
Once you know what your child is allergic to, the doctor can help you take the guesswork out of managing symptoms.