Allergic reactions are caused by the interaction of a person's immune system with the outside world. Foreign proteins especially small proteins from pollens, molds and dust mites can cause an immune reaction in an individual. If the immune reaction induced by these foreign proteins, otherwise referred to as allergens, involves IgE antibodies, then the possibility exists for an allergic reaction to occur. Any substance which is able to induce a person to make an allergy antibody type of immune reaction is referred to as an allergen. The most common causes of allergy and asthma symptoms are allergens derived from pollens, molds, house dust mites, animal danders and insects.
Many people also experience symptoms of allergy due to altered reactions to foods and medications.
Most often, this will also involve a number of allergy skin tests which are used to detect the real causes of the allergic reactions and consequent symptoms. The diagnosis of an allergic disease cannot be made by a blood test alone. Serum testing is commonly done as a screening test to determined increased risks of developing allergy-like symptoms. The blood tests for allergy, however, do not tell your doctor with certainty whether or not the allergens being tested for are causing your symptoms. Allergy really has different names depending upon where in your body the reaction is occurring.