How Are Allergies Diagnosed?
Some allergies are fairly easy to identify but others are less obvious because they can be similar to other conditions.
If your child has cold-like symptoms lasting longer than a week or two or develops a “cold” at the same time every year, talk with your doctor, who might diagnose an allergy and prescribe medicines, or may refer you to an allergist (a doctor who is an expert in the treatment of allergies) for allergy tests.
To find the cause of an allergy, allergists usually do skin tests for the most common environmental and food allergens. A skin test can work in one of two ways:
A drop of a purified liquid form of the allergen is dropped onto the skin and the area is scratched with a small pricking device.
A small amount of allergen is injected just under the skin. This test stings a little but isn’t painful.
After about 15 minutes, if a lump surrounded by a reddish area (like a mosquito bite) appears at the site, the test is positive.
Blood tests may be done instead for kids with skin conditions, those who are on certain medicines, or those who are very sensitive to a particular allergen.
Even if testing shows an allergy, a child also must have symptoms to be diagnosed with an allergy. For example, a toddler who has a positive test for dust mites and sneezes a lot while playing on the floor would be considered allergic to dust mites.
