Skin tests may be used to diagnose allergies to certain substances. In this test, the skin on the back or the arms is pricked with one or more small doses of substances (allergens) that might cause an allergy. The amount of swelling and redness at the sites of the skin pricks is measured to see which allergens cause a reaction.

Skin tests may be recommended for people with asthma. If you have asthma, avoiding substances that cause a reaction (triggers) may improve your asthma symptoms. For some people, allergy shots (immunotherapy) may be helpful.

For more information on skin tests, see the topic Allergic Rhinitis.