Allergy Sweet Vernal Grass test is performed in order to check the level of IgE antibodies present in the blood of an individual. It detects whether the person is allergic to sweet vernal grass or not. It also detects the allergens that are responsible for the cause of symptoms. This test also determines the specific allergic reactions to drugs or chemicals or vnom allergens. This test is not so useful for those people, who have already taken immunotherapy treatment and cannot be able to determine the existence of residual clinical sensitivity. IgE antibodies level in the blood will vary according to the concentration.