What is hay fever?

Hay fever is a term used for allergies that occur during certain seasons of the year. Hay fever usually occurs in the spring, summer, or fall. Some people have hay fever during all 3 of these seasons.

How does it occur?

Seasonal allergy symptoms are reactions of your body to substances that the body sees as foreign. Substances that cause an allergic reaction are called allergens.

The allergens causing hay fever float in the air and are spread by the wind. Pollen and molds are the two main types of seasonal allergens. The type of pollen in the air depends on the growing season and the area of the country. Molds may be present year-round, especially in damp spaces of buildings and in furniture, such as mattresses and pillows. You may be allergic to all molds or just to molds that are present during one particular season.

The parts of the body that may be affected by hay fever are the eyes; the lining tissue of the nose, sinuses, and eustachian tube (which connects the middle ear with the back of the throat); and, less often, the lungs. When the pollen or molds come into contact with these tissues in an allergic person, cells in the tissues release a chemical called histamine. Histamine causes the tissues to itch, swell, and produce more mucus or tears than is normal. If you have asthma and you breathe into your lungs the substances you are allergic to, you may have symptoms of asthma.

What are the symptoms?

Common upper-respiratory symptoms of hay fever include:

• sneezing
• runny nose
• itchy nose, throat, or ear canals
• ear congestion
• itchy, watery eyes
• postnasal drainage.

Lower-respiratory symptoms that may occur are:

• shortness of breath, especially with exercise or exertion
• frequent coughing
• wheezing.

How is it diagnosed?

Hay fever is usually diagnosed from your medical history. If your symptoms occur just in certain seasons, your health care provider will suspect that you have hay fever. A check of your ears, nose, throat, and lungs may confirm the diagnosis.

You may have tests for specific allergies. For most people the best tests are skin scratch or prick tests. In these tests a health care provider places tiny amounts of suspected allergens under your skin and looks for reactions. These allergy tests may find which allergens are causing your symptoms. In some cases you may have blood tests 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, you may need allergy tests.

How is it treated?

The goals of treatment for hay fever are to:

• Make you more comfortable.
• Help you function better at work and at home.
• Prevent problems such as ear infections, sinus infections, and asthma attacks.

Once you know what you are allergic to, you can try to avoid the allergens. For example, using an air conditioner rather than an attic fan lessens the amount of pollen that gets into your home.

Many hay fever symptoms are so mild that they need no treatment. Or you may just need to take a nonprescription medicine once in a while. If you need further treatment, a variety of medications are available, such as decongestants, antihistamines, and steroid nasal sprays.

Decongestants can be used alone to shrink the swollen lining tissues of the ear, nose, and sinuses. Possible side effects of decongestants are trouble sleeping, rapid heart rate, and elevated blood pressure.

Antihistamine medicines fight the effects of the release of histamine by your tissues. You can take them when your symptoms are bothering you. In more severe cases, you may take them every day to prevent symptoms during your allergy season(s). There are different types of antihistamines. A common side effect of many antihistamines is drowsiness. This may not be a problem if 1 dose at bedtime dose is all you need. It may also not be a problem if you are able to try the medication for several days despite the drowsiness. Often the drowsiness goes away after you have taken the drug for 3 to 5 days. Some new "nonsedating" antihistamines are available that usually don't cause drowsiness. They work well for most people, but they tend to be more expensive.

It is safe to take both antihistamines and decongestants together as long as you have no other reason for not taking them.

If antihistamines do not help eye symptoms caused by your allergy, your health care provider may prescribe eye drops.

Prescription nose sprays are very effective in preventing or minimizing nasal and sinus congestion, runny nose, and postnasal drainage. Two types of sprays are available: steroid and cromolyn. They work best to prevent symptoms if you use them on a regular basis during the allergy season. Both may be used safely with antihistamines and decongestants.

Respiratory symptoms are treated with medicines used to treat asthma: quick-acting, inhaled bronchodilators to treat ongoing symptoms and other types of inhaled medicines to prevent symptoms. You may need a combination of these medicines.

You may need to consider having allergy tests if your symptoms are intolerable despite medications or if you have frequent complications. The purpose of testing is not just to identify specific allergens, but to allow weekly allergy injections. A mixture is prepared that contains the allergens identified in your allergy tests. The mixture is injected into your skin in tiny but increasing amounts over the course of many months. The injections eventually desensitize you to the allergens. Usually, after 4 to 6 months of allergy shots, people begin to have relief from their allergies. However, you may need to continue the shots for 2 to 3 years or longer.

How long will the effects last?

Allergies last different amounts of time for each person. Allergies can develop at any age. Children with seasonal allergies may continue to have allergies as they grow older or the allergies may go away over time. If you start having allergies as an adult, you will probably continue to have them. However, the allergies may stop if you move to an area where the substances causing your allergies are not present.

What can be done to help prevent hay fever?

There are no known methods or techniques for preventing allergies. However, some doctors think that breast-fed babies may be less likely to develop allergies. Also, if your family has a very strong history of allergies, you might try to avoid your family's most common allergens. This may help prevent severe symptoms.