What should you know about positive control allergy test?

In a skin-prick test, the positive control is expected to cause a small local reaction. It supports assessment of the test process and skin reactivity. It does not show that you are allergic to every substance tested, and it cannot diagnose Food Allergy, Pet Allergy or House Dust Mite Allergy alone. Medicines, skin conditions and technique can affect results, so each allergen response is compared with your symptoms and exposure pattern.

Ask which control was used, whether the response was adequate and which allergen results fit your history. Tell the testing team about every medicine, including antihistamines, because some can reduce skin responses. Do not remove foods or avoid animals solely because of a result. A targeted plan is safer than broad restriction when symptoms involve the nose, eyes, chest or digestion.

During or after testing, seek emergency help for throat or tongue swelling, trouble breathing, faintness, widespread hives or rapidly worsening symptoms. These can be signs of Anaphylaxis. A small itchy bump at the test site is different, but report any reaction that spreads or persists.

Which allergen results are clinically meaningful? Could my medicines have changed the test? Do I need a blood test or advice for Allergic Rhinitis, Asthma or eye symptoms?