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Allergic Rhinitis

The immune system protects the body against potentially harmful substances, such as bacteria and viruses. An allergy is an exaggerated immune response to a substance(s) that is (are) generally not harmful. Allergic rhinitis is a collection of symptoms, predominantly in the nose and eyes, caused by airborne particles of dust, dander, or plant pollens in people who are allergic to these substances. Allergies to pollen are commonly called “hay fever.” Persons with a history of asthma or eczema are more likely to have allergic rhinitis.

When an allergen such as pollen or dust is inhaled by a person with a sensitized immune system, it triggers antibody production. These antibodies bind to cells that contain histamine. When the antibodies are stimulated by pollen and dust, histamine (and other chemicals) is released.

Common symptoms include: sneezing, stuffy, runny, itchy nose, itchy, watery, eyes, itchy, skin and throat. You may also experience problems breathing, chronic fatigue, poor appetite, nausea and frequent headaches. Severe allergies can cause hives or even a life-threatening reaction, “anaphylaxis.”

Causes

Seasonal allergic rhinitis (commonly called hay fever) usually results from tree, grass, flower or ragweed pollen. With this type of rhinitis, symptoms will decrease with the arrival of cold weather.

Perennial allergic rhinitis can cause year-round symptoms. This allergic reaction is the result of indoor irritants such as feathers, dust, mold spores, animal dander or dust mites.

Because different types of pollen, dust and mold spores occur in various geographic locations, if you move or travel, you may suddenly develop allergic rhinitis.

Prevention

You cannot prevent an allergy, but you can minimize a reaction. The most effective method to prevent a reaction is to avoid the allergen that triggers your allergic response. Try these steps:

• If you are allergic to warm-blooded animals, confine your pet to a particular area of your home. It is especially important to keep pets out of the bedroom. If the effects on your health are severe, consider giving your pet away.
• Avoid pollen by using air conditioning and avoiding outside activity during pollen season. There is more pollen in the air on hot, windy days than on rainy days. Consult the pollen forecast when planning activities.
• Check the material from which your pillows and comforters are made. Feathers, foam rubber, or pillows more than five years old may contribute to your allergies.
• Avoid dust and mold. Since this is difficult and it may be impractical for you to create an "allergy-proof" home, at least make sure your bedroom is as allergen-free as possible:
  - move out all unnecessary furniture
  - keep windows tightly shut
  - frequently clean the curtains, blinds, bedding and carpeting
  - use pillows and comforters stuffed with Dacron or polyester
  - enclose mattresses and box springs in plastic
  - cover or filter all vents
  - purchase a HEPA filter for your sleeping area and possibly for other areas of your home
  - move out decorative pillows, books, and stuffed animals
  - keep the floors bare
  - use dusting products formulated to hold the dust
  - store clothing so dust will not settle on it
  - never sweep - use a vacuum only

These tips can help decrease the severity of your allergic symptoms:

• Maintain a balanced diet to improve your body's ability to heal itself
• Sleep with your head elevated to prevent nasal congestion during the night
• Drink adequate fluids (eight 8-ounce glasses per day) to loosen the secretions in your nose and throat
• Exercise regularly

Diagnosis

It is not always easy to diagnose allergic rhinitis. Many symptoms are similar to those of a cold.

You and your practitioner may notice that you have symptoms every August (or May) and that the symptoms last for about the same amount of time each year. If you have perennial allergic rhinitis, it is even harder to diagnose because there is no clear pattern of illness. Sometimes your practitioner may order blood and skin tests to determine whether or not you have an allergy.

Treatment

The best treatment for your allergy is to avoid the allergen. When this is not possible, medication can usually control the symptoms. Because each individual is unique, there is no standard treatment for allergic rhinitis. The best medication can only be determined by you and your practitioner. It may take several trials to determine the best medication and the optimal dosage.

These medications are used to treat allergic rhinitis:

• Short-acting antihistamines, such as Benadryl, chlorpheniramine, and brompheniramine, which are generally over-the-counter (non-prescription) but can cause drowsiness.
• Longer-acting antihistamines, like fexofenadine (Allegra), and cetirizine (Zyrtec) cause less drowsiness, but can be equally effective.
• Decongestants: The decongestant pseudophedrine can give short-term relief from nasal stuffiness. Use of decongestant nasal sprays for longer than three days at a time can cause a "rebound" effect that ultimately makes you even more congested than before.
• Corticosteroids may lessen your allergic reaction by preventing body cells from responding to histamine. For allergic rhinitis, these compounds are administered via a nasal spray. Minimal side effects have been found even with long term use. For profound allergy symptoms, such as hives, a very short course of systemic cortisteroid may be considered.
• Immunotherapy (allergy shots) are effective only when a specific allergen can be identified. Some allergies respond well to this treatment. Immunotherapy is not a "quick fix" and may take a year or more before the effectiveness is noted.

References:

Family Doctor web site: http://familydoctor.org/online/famdocen/home.html
Medline Plus web site: http://www.nlm.nih.gov/medlineplus/

Resources:

deShazo, Richard D & Kemp, Stephen F. “Patient information: Allergic rhinitis (seasonal allergies)” UpToDate Online 18.1. Ed. Corren, Jonathan. 6 Jan 2009. Accessed 22 June 2010.
American College of Allergy, Asthma & Immunology web site: http://www.acaai.org/