If you are doubt of the allergy problem, you will need various tests to diagnosis and pick a treatment then. Here is two types of allergies test.
Skin tests
This test is conducted by placing a small amount of a suspected allergen on or below the skin to see if a reaction develops.
There are three types of skin tests:
- Skin prick test. By placing separate drops of solutions of allergen extracts onto the skin of your forearm or back and then using a very fine lancet to prick through the drop into the skin. A positive test results in a small raised wheal with a red surrounding flare. Test is painless and give results after around fifteen minutes. It may be necessary for you to stop certain medications such as anti-histamine medications before a skin prick test but you should only do this under the supervision of a doctor. Oral or inhaled steroids do not interfere with skin prick tests.
- Intradermal test. By injecting a small amount of the allergen solution into the skin. An intradermal allergy test may be done when a substance does not cause a reaction in the skin prick test but is still suspected as an allergen for that person. The intradermal test is more sensitive than the skin prick test but is more often positive in people who do not have symptoms to that allergen (false-positive test results).
- Skin patch test. By placing the allergen solution on a pad that is taped to the skin for 24 to 72 hours. This test is used to detect a skin allergy called contact dermatitis.
Blood test
Allergy blood tests look for substances in the blood called antibodies. Blood tests are not as sensitive as skin tests but are often used for people who are not able to have skin tests.
The most common type of blood test used is the enzyme-linked immunosorbent assay (ELISA, EIA). It measures the blood level of a type of antibody (called immunoglobulin E, or IgE) that the body may make in response to certain allergens. IgE levels are often higher in people who have allergies or asthma.
Other lab testing methods, such as radioallergosorbent testing (RAST) or an immunoassay capture test (ImmunoCAP, UniCAP, or Pharmacia CAP), may be used to provide more information.