Allergy

by Harissios Vliagoftis, MD

Allergic diseases affect more than 1 of every 4 individuals in Canada. The most common condition is allergic rhinitis or hay fever. Asthma, food allergies and skin allergies including hives and various rashes are also very common diseases that have a large impact on the quality of life of sufferers. Drug allergies may be less common but are quite serious conditions that can limit the ability to treat patients with the appropriate medications.

People have the tendency to call “allergy” every reaction that they associate with environmental exposures or exposures to foods and drugs as well as many other conditions of unknown etiology that mystify them and their doctors. The definition of allergy however is very specific. Certain people that have a predisposition to develop allergies react to environmental exposures, to foods or to drugs with production of IgE antibodies. IgE molecules are produced by cells of our immune system, circulate in our blood and reach peripheral tissues where they bind to cells called “mast cells”. When this individual later inhales the same protein or eats the same food or takes the same drug, these “allergens” (pollens, animal dander, foods, drugs) bind to the IgE that is found on mast cells and activate mast cells to release substances that cause symptoms of allergies. The most common and one of the most potent of these substances is histamine. Histamine is responsible for many of the symptoms we develop with allergic reactions and that is the reason that antihistamines are very useful as treatment of allergic diseases.

If you suspect you have an allergy a visit to your doctor can help. Your doctor can take a detailed history and do an appropriate physical exam. If allergy is a concern your doctor may also obtain certain tests to identify the specific exposure responsible for your symptoms or he may refer you to an allergist. Your doctor may also refer you to a respirologist if your main problem is respiratory allergies or a dermatologist if you suffer primarily from skin allergies.

Effective drugs to fight allergies exist and your doctor can prescribe them. The most commonly used drugs are antihistamines and those you can buy without a doctor’s prescription. Your family doctor but also your pharmacist can help you identify one that will work for your symptoms.

Food allergies are a large problem in our communities. However, we should keep in mind that the majority of reactions that develop soon after we ingest certain foods are not food allergy. Because we come in contact with foods multiple times a day, it is easy to associate any reaction we develop with food consumption. Many reactions to food can be the result of toxic substances in the foods. However, the majority of reactions are the result of “intolerance” to foods and although these reactions are very irritating they are less dangerous than true allergic reactions. If you suspect you have food allergies talk to your doctor and, if needed, get a referral for an allergist.

Naturopaths and other non-medical health care providers in many instances favor tests that are unproven and generally not helpful for diagnosis of allergies. Discuss your concerns with your family doctor before seeing an alternative practitioner and before you spend money on these unproven tests.

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