Allergy tests are used to find the substances that are causing
an allergic reaction. An allergic reaction is an immune system
response to a substance in the environment known as a trigger.
The healthcare professional may perform or order allergy tests
on people with suspected allergies. Skin testing is usually not
done on children younger than age 3. It may be done on older
individuals to determine the triggers that are causing allergic
reactions in the person. Before the procedure, a person should
not take medicines, such as antihistamines, that could block a
skin reaction and thus cause the test to turn out falsely
negative. There are many methods of allergy testing. Skin tests
are used to identify specific allergens that are known to cause
symptoms. The healthcare professional will select skin tests
based on a person's particular history. Test solutions are made
from extracts of various inhaled, ingested, or injected
substances. Test solutions available include extracts from tree,
grass, and weed pollens;