What is hay fever?

Hay fever is the common 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 three seasons.

How does it occur?

Seasonal allergy symptoms are reactions of your body to substances that the body perceives 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. The two main types of seasonal allergens are pollen and molds. The type of pollen present 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. A person may be allergic only to molds that are present during one particular season or to all molds.

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, symptoms of asthma may be triggered.

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?

The diagnosis of hay fever is usually made from your medical history, based on a seasonal occurrence of symptoms. An ear, nose, throat, and lung exam may confirm the diagnosis.

Tests for specific allergies may be performed. 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 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 goals of treatment of hay fever are to make you more comfortable, help you be more effective at work and at home, and prevent complications 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 they require no treatment or they respond to an occasional nonprescription medication. When further treatment is required, a variety of medications are available, such as decongestants and antihistamines.

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

Antihistamines counteract the effects of the release of histamine by your tissues. They can be taken when your symptoms are bothering you or, in more severe cases, on a daily basis 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 a bedtime dose is sufficient treatment for you. 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 are very effective for most people, but they tend to be more expensive.

It is safe to take both antihistamines and decongestants, as long as you have no other medical problems that rule out their use.

If antihistamines are not effective for eye symptoms caused by your allergy, your health care provider may prescribe eye drops. Three new types of eye drops have become available recently.

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 medications used to treat asthma: bronchodilators, inhaled steroids, or anti- inflammatory medication such as cromolyn. A combination of these medications may be necessary.

Allergy sufferers who have intolerable symptoms in spite of medications, or who have frequent complications, need to consider allergy testing. 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?

The duration of allergies varies with each person, and 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. If your family has a very strong history of allergy, it may be helpful, if you can, to try to avoid the family's most common allergens in an attempt to minimize the severity of symptoms.