Overview Allergic rhinitis is an inflammation of the nasal mucosa, the membrane or tissue that lines the inside of the nose. Most of us know it simply as hay fever. It is a very common condition affecting millions of Canadians. It can occur at any time of the year, but is more common in the spring and fall.
Causes All allergies are caused by an oversensitive immune system. Hay fever is no different. In this case, the trigger is pollen from plants, flowers, grass and weeds. Just one ragweed plant can generate one million grains of pollen and it takes fewer than a thousand to trigger an allergic reaction.
When pollen is inhaled, the body produces antibodies such as histamine that are stored in mast cells in the nose and eyes. These antibodies are designed to fight what the body perceives as an invader. Allergy sufferers have higher levels of these chemicals than most people, so when they breathe in pollen, more histamine is released into their bodies, triggering a variety of telltale symptoms.
Symptoms Many people think they have a cold or virus when they began suffering from allergies. The reason: Many of the signs of a cold -- watery eyes, runny nose, congestion, itchy throat -- are also symptoms of allergies. So how do you know the difference? The most prominent sign of allergy is that it involves itchiness in the eyes, nose, throat and even ears. Colds don't do that. Another sure-fire sign is the length of time symptoms persist. Nasal congestion that lasts more than five days is unlikely to be the result of a cold. Doctors can determine if you have an allergy by examining the inside of the nose. With allergies, the mucus membrane inside the nose is pale, but when there is an infection it is usually red.
Treatment There is relief available for people with allergies. These range from targeted therapies such as “nasal puffers” and eye drops, to more generalized therapies such as antihistamines. Your doctor may recommend visiting an allergist so that he or she can try to identify the triggers so that you can avoid them. Also an allergist will be able to diagnose whether your symptoms may require more intensive medical intervention.
Although most people cope with seasonal self-treatment, if the season is long and you don't respond to the medication, you may need allergy injections, which significantly reduce the symptoms by building up a blocking antibody to them. Called immunotherapy, the shots involve the injection of tiny amounts of allergenic extracts, usually over a period of three to five years. By gradually increasing the amount of extract, tolerance to the troublesome allergen will increase, and symptoms will usually be relieved.
Prevention The best way to prevent hay fever is to avoid the pollen that triggers an allergic reaction:
Keep windows closed at night to prevent pollen from drifting into your home.
Keep your early morning outdoor activities to a minimum. That's when trees and plants usually emit pollen.
Close your car windows.
Stay indoors when pollen counts are high and on windy days when pollen is being blown around.
Be sure to take medications prescribed by your allergist.
Don't hang bed sheets or clothing out to dry. They may collect pollen.
