What is allergic rhinitis?

Allergic rhinitis is an allergic reaction of the lining of the nose. Seasonal allergic rhinitis is also called hay fever.

How does it occur?

Allergic rhinitis occurs when the nose and usually also the ears, sinuses, and throat come into contact with allergy- causing substances. The allergy-causing substances are called allergens. The most common allergens are pollens, molds, dust, and animal dander. Some allergens are present only during certain seasons, for example, ragweed in the fall. Others are present year-round, for example, the mites in house dust.

When the lining tissues of the nose and sinuses come into contact with allergens, a chemical called histamine is released from cells in these tissues. Histamine causes the nose lining to swell, itch, and produce excess mucus.

What are the symptoms?

Common symptoms of allergic rhinitis are

• itchy, runny nose
• sneezing
• nasal and head congestion.

Other possible symptoms include

• fatigue and lethargy
• itchy throat
• postnasal drainage.

How is it diagnosed?

Your medical history is usually the basis for the diagnosis of allergic rhinitis. Knowledge of a family history of allergic problems is also helpful. However, it may take some detective work to figure out exactly what you are allergic to.

Your health care provider may swab the lining of your nose to obtain a sample of mucus. About 50% of people with allergies have cells in their mucus that indicate allergy.

Tests for specific allergies may be performed. For most people the best tests are skin scratch or prick tests. In these tests your health care provider or an allergy specialist places tiny amounts of suspected allergens under your skin and looks for reactions. These allergy tests will identify which of many possible allergens are causing your symptoms. In some cases blood tests may be done to look for antibodies to suspected allergens.

Because allergy tests are expensive, your health care provider will probably recommend that you try treating your symptoms with medication first. If medications do not control your symptoms, allergy testing may be needed.

How is it treated?

The first principle of allergy treatment is to avoid the allergy-causing substance. Air conditioners and special filters can minimize the amount of pollen and mold that circulates indoors. Try not to use an attic fan if you are allergic to pollen. Putting plastic covers on mattresses may help you avoid dust and mold. Pillows may also be covered with plastic.

When environmental measures such as the ones described above are inadequate to control symptoms, medication is usually effective. Your provider may suggest that you first try nonprescription decongestants for mild symptoms. Side effects of the decongestants often include rapid heart rate and insomnia. These medications can also raise blood pressure of some people.

Nonprescription antihistamines are helpful, especially if used only at bedtime because they may cause drowsiness. Often the drowsiness will subside after you have taken the antihistamine for 3 to 5 days.

Prescription antihistamines are usually very effective in treating and preventing allergy symptoms. The new "nonsedating" antihistamines do not usually cause drowsiness and are taken once or twice a day. Some people take antihistamines only on the days they are having symptoms. Others start the medication at the beginning of their usual allergy season and continue taking it until the season is over.

It is safe to take antihistamines and decongestants together if you have no medical reason not to take them together.

When antihistamines and decongestants do not sufficiently control your allergy symptoms, prescription nasal sprays may be added to your treatment. Two types of sprays are available: steroid and cromolyn. Depending on a person's other allergy symptoms, sometimes the nasal spray will be the first and only medication required.

If your symptoms are severe in spite of medications, you should consider getting allergy shots (immunotherapy). Allergy shots will desensitize you to the substances that cause your allergies. A mixture of the allergens identified from your allergy tests is prepared. You then receive weekly injections of this mixture. Usually after 4 to 6 months of allergy shots people begin to have relief from their allergies. However, you will probably need to continue the shots for 2 to 3 years or longer.

Proper treatment of allergy symptoms is the best way to prevent complications of allergic rhinitis, such as ear and sinus infections.

How long will the effects last?

If childhood allergies persist into adulthood, they will likely be present for a lifetime. New allergies can develop any time, even in previously nonallergic persons. Allergy symptoms are dependent not only on season and weather but also on location. Hence, your allergies may wax and wane, depending on where you are living.

What can I do to help prevent allergic rhinitis?

There are no known ways to prevent the development of allergic rhinitis. Once allergies have developed, you can try to limit exposure to the things that cause them, for example, pollens or animals. In severe cases, you may need to move to another area, but you may develop allergies there as well.