How Does Skin Testing Work

Basically, skin testing tries to trigger a tiny allergic reaction in just the area of skin being tested. Very diluted (weak) and very small amounts of drug are used. The test is performed in the very top layer of skin, and almost no substance gets into the blood stream, so that “whole-body” symptoms do not occur. 

The test is very well-studied, very common, and very safe. When your body has an allergic reaction, it occurs because your body’s immune system treats a substance like a dangerous invader when the substance should be viewed as harmless. The reaction of your immune system is what causes the symptoms of allergy. 

When the cells of your immune system detect the allergen, they release chemicals, such as histamine, which are the main cause of symptoms. These cells are found in many parts of your body, and they cause symptoms of allergy according to their location. Some of these cells are found in your skin, and therefore rash is a common part of allergy. Skin testing aims to trigger and observe rash forming on the area of skin used for testing.

Skin Test