Allergy testing

Allergy Testing

Allergy testing is a method used to identify the substances causing an allergic reaction. These substances, known as allergens, can include foods, pollen, dust mites, molds, insect stings, and certain medications. Allergy testing can be performed in several ways, including skin tests, blood tests, and elimination diet tests.

Types of Allergy Tests

Skin Tests

Skin tests are the most common form of allergy testing. They involve applying a small amount of a suspected allergen to the skin using a tiny needle. If the patient is allergic to the substance, they will develop a raised bump or rash at the test site. There are three types of skin tests: the prick test, the intradermal test, and the patch test.

Blood Tests

Blood tests, such as the radioallergosorbent test (RAST) and the enzyme-linked immunosorbent assay (ELISA), are used when skin tests are not possible or practical. These tests measure the amount of specific antibodies, known as IgE antibodies, in the blood when exposed to specific allergens.

Elimination Diet Tests

Elimination diet tests are used to identify food allergies. They involve removing specific foods from the patient's diet and then gradually reintroducing them to see if an allergic reaction occurs.

Procedure

The procedure for allergy testing depends on the type of test being performed. Skin tests are usually done in a doctor's office and results are typically available within 20 minutes. Blood tests require a blood sample to be taken and sent to a lab for analysis, with results usually available within a few days. Elimination diet tests can take several weeks to complete, as foods must be eliminated and then reintroduced one at a time.

Risks and Complications

While allergy testing is generally safe, there are some risks and potential complications. These can include anaphylaxis, a severe allergic reaction, particularly with skin tests. Other potential complications can include fainting, light-headedness, and skin infections.

See Also

• Allergen
• Anaphylaxis
• Immunoglobulin E
• Food Allergy

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