Medical history and examination is usually sufficient to make a diagnosis, but additional allergy testing may be helpful when the causative allergen is not clear.
Skin prick test
Skin prick testing is one of the most common allergy tests. It involves putting a drop of liquid onto your forearm that contains a substance you may be allergic to. The skin under the drop is then gently pricked. If you are allergic to the substance, an itchy, red bump will appear within 15 minutes.
Skin prick testing is painless and very safe. It is important not to take any antihistamine medications before the test as they interfere with the results.