Allergy test is done to find out what substances or allergens are causing an allergic reaction in a person's body. Skin allergy is a common form of allergic disease. So once the harmful substances are identified, it would be easier for the person to avoid them in the future. It would also help the general physician in advance to treat the symptoms. Skin tests are most commonly done because they are reliable and less expensive than blood tests. In a skin test, a small patch of the allergen is placed on the surface of the skin to see if it reacts to it. There are three types of skin tests: Skin prick test - This test is carried out by placing a small drop of solution containing the possible allergen on the surface of the skin. The reactions are noted, and the potential treatments are carried out. Intradermal test - In this test, Instead of placing on the skin, the solution is directly injected into the skin. Once again if the reaction develops, the conditions are treated. Skin patch test - In this trial, the allergen solution is placed on a pad, and is then taped to the skin for a period of time. This test is used to determine a type of skin allergy called contact dermatitis. Skin allergy can be of various kinds, and the above tests can be helpful in determining if the person has an allergic reaction to grass, trees, and particular types of food, etc. The results are thoroughly examined, and the person will be advised to take proper precaution when dealing with them in the future.