Allergy - Coffee Test

An IgE (Immunoglobulin E) test along with skin scratch test is performed on a patient to know whether they are allergic to certain food items. In this case, we will be checking whether a person is allergic to coffee or not. An IgE test measures the blood level of IgE, one of the antibodies present in our bodies. Antibodies are made by our immune system in order to protect our body from antigens like Bacteria, Virus, allergens. These antibodies are mostly found in lungs, skin and mucous membranes. Scratch test on the skin is performed to confirm if the person is allergic to that particular allergen or not.

No special preparation is required for these tests, Wearing a short sleeve or sleeveless shirt or T-shirt will be helpful for the technicians to draw blood from the veins and pricking your forearm.

IgE Test: This test is performed as an initial screening test for allergies. It is used to check whether a person is allergic to certain food items or not. If a person is allergic, the allergen binds with IgE hence histamine is released into the blood to fight off the allergens.

Scratch Test: This test is used to confirm a person’s allergy along with IgE test. The technician will be able to see the allergic reaction directly. This test is advised to be done by a person who can handle a reaction caused by the allergy.

For IgE Test: For the blood to be drawn, at first the area is cleansed with an antiseptic and tourniquet is placed around the upper arm for pressure. A needle is inserted into the vein and blood is drawn and collected in a vial. Now, the tourniquet is removed and the patient is provided with cotton balls to prevent further bleeding. However, if this test is to be undertaken for an infant, blood is drawn from the heel by pricking it with a lancet.For Scratch Test: The technician pricks or scratches the skin’s surface with a liquid extract of the allergen. In this case coffee is brewed and used. The technician will wait for 15 minutes to check whether the patient’s skin reacts to the allergen or not. If not, A combination of allergen are used in the test. This test sure is uncomfortable but not much painful.