An allergy is a reaction of your immune system to something that does not bother most other people. People who have allergies often are sensitive to more than one thing. Substances that often cause reactions are

• Pollen

• Dust mites

• Mold spores

• Pet dander

• Food

• Insect stings

• Medicines

How do you get allergies? Scientists think both genes and the environment have something to do with it. Normally, your immune system fights germs. It is your body's defense system. In most allergic reactions, however, it is responding to a false alarm.

Allergies can cause a runny nose, sneezing, itching, rashes, swelling or asthma. Symptoms vary. Although allergies can make you feel bad, they usually won't kill you. However, a severe reaction called anaphylaxis is life-threatening.

Indoor Air Pollution

We usually think of air pollution as being outdoors, but the air in your house or office could also be polluted. Sources of indoor pollution include

• Biological contaminants like mold and pollen

• Tobacco smoke

• Household products and pesticides

• Gases such as radon and carbon monoxide

• Materials used in the building such as asbestos, formaldehyde and lead.

Sick building syndrome occurs when several people are affected, but no specific source of the illness is found. Indoor air quality problems usually only cause discomfort, and most people feel better as soon as they eliminate the source of the pollution. However, some pollutants can cause diseases that show up much later, such as respiratory diseases or cancer. Making sure that your building is well-ventilated and eliminating pollutants can improve the quality of your indoor air.

Sinusitis

Sinusitis means your sinuses are infected or inflamed. Your sinuses are hollow air spaces within the bones surrounding the nose. They produce mucus, which drains into the nose. If your nose is swollen, this can block the sinuses and cause pain and infection.

Sinusitis can be acute, lasting for less than four weeks, or chronic, lasting much longer. Acute sinusitis often starts as a cold, which then turns into a bacterial infection. Allergies, pollutants, nasal problems and certain diseases can also cause sinusitis.

Symptoms of sinusitis can include fever, weakness, fatigue, cough and congestion. There may also be mucus drainage in the back of the throat, called postnasal drip. Treatments include antibiotics, decongestants and pain relievers. Using heat pads on the inflamed area, saline nasal sprays and vaporizers can also help.

Food Allergies

According to the National Institute of Allergy and Infectious Diseases, a food allergy is an abnormal response to a food triggered by your body's immune system. Allergic reactions to food can sometimes cause serious illness and death. Tree nuts and peanuts are the leading causes of deadly allergic reactions called anaphylaxis.

In adults, the foods that most often trigger allergic reactions include

• Fish and shellfish, such as shrimp, lobster and crab

• Peanuts

• Tree nuts, such as walnuts

• Eggs

Problem foods for children are eggs, milk (especially in infants and young children) and peanuts.

Sometimes a reaction to food is not an allergy. It is often a reaction called "food intolerance". Your immune system does not cause the symptoms of food intolerance. However, these symptoms can look and feel like those of a food allergy.

How to Create a Dust-Free Bedroom

If you are dust-sensitive, especially if you have allergies and/or asthma, you can reduce some of your misery by creating a "dust-free" bedroom. Dust may contain molds, fibers, and dander from dogs, cats, and other animals, as well as tiny dust mites. These mites, which live in bedding, upholstered furniture, and carpets, thrive in the summer and die in the winter. They will, however, continue to thrive in the winter if the house is warm and humid. The particles seen floating in a shaft of sunlight include dead mites and their waste products. The waste products actually provoke the allergic reaction.

The routine cleaning necessary to maintain a dust-free bedroom also can help reduce exposure to cockroaches, another important cause of asthma in some allergic people.

You probably cannot control dust conditions under which you work or spend your daylight hours. To a large extent, however, you can eliminate dust from your bedroom. To create a dust-free bedroom, you must reduce the number of surfaces on which dust can collect.

In addition to getting medical care for your dust allergy and/or asthma, the National Institute of Allergy and Infectious Diseases suggests the following guidelines.

PREPARATION

• Completely empty the room, just as if you were moving.

• Empty and clean all closets and, if possible, store contents elsewhere and seal closets.

• Keep clothing in zippered plastic bags and shoes in boxes off the floor, if you cannot store them elsewhere.

• Remove carpeting, if possible.

• Clean and scrub the woodwork and floors thoroughly to remove all traces of dust.

• Wipe wood, tile, or linoleum floors with water, wax, or oil.

• Cement any linoleum to the floor.

• Close the doors and windows until the dust-sensitive person is ready to use the room.

MAINTENANCE

• Wear a filter mask when cleaning.

• Clean the room thoroughly and completely once a week.

• Clean floors, furniture, tops of doors, window frames and sills, etc., with a damp cloth or oil mop.

• Carefully vacuum carpet and upholstery regularly.

• Use a special filter in the vacuum.

• Wash curtains often at 130 degrees Fahrenheit.

• Air the room thoroughly.

CARPETING AND FLOORING

Carpeting makes dust control impossible. Although shag carpets are the worst type to have if you are dust sensitive, all carpets trap dust. Therefore, health care experts recommend hardwood, tile, or linoleum floors. Treating carpets with tannic acid eliminates some dust mite allergen. Tannic acid, however, is

• Not as effective as removing the carpet

• Is irritating to some people

• Must be applied repeatedly

BEDS AND BEDDING

Keep only one bed in the bedroom. Most importantly, encase box springs and mattress in a zippered dust-proof or allergen-proof cover. Scrub bed springs outside the room. If you must have a second bed in the room, prepare it in the same manner.

Use only washable materials on the bed. Sheets, blankets, and other bedclothes should be washed frequently in water that is at least 130 degrees Fahrenheit.

• Lower temperatures will not kill dust mites.

• If you set your hot water temperature lower (commonly done to prevent children from scalding themselves), wash items at a laundromat which uses high wash temperatures.

Use a synthetic, such as Dacron, mattress pad and pillow. Avoid fuzzy wool blankets or feather- or wool-stuffed comforters and mattress pads.

FURNITURE AND FURNISHINGS

Keep furniture and furnishings to a minimum.

• Avoid upholstered furniture and blinds.

• Use only a wooden or metal chair that you can scrub.

• Use only plain, lightweight curtains on the windows.

AIR CONTROL

Air filters-either added to a furnace or a room unit-can reduce the levels of allergens. Electrostatic and HEPA (high-efficiency particulate absorption) filters can effectively remove many allergens from the air. If they don't function right, however, electrostatic filters may give off ozone, which can be harmful to your lungs if you have asthma.

A dehumidifier may help because house mites need high humidity to live and grow. You should take special care to clean the unit frequently with a weak bleach solution (1 cup bleach in 1 gallon water) or a commercial product to prevent mold growth. Although low humidity may reduce dust mite levels, it might irritate your nose and lungs.

CHILDREN

In addition to the above guidelines, if you are caring for a child who is dust-sensitive

• Keep toys that will accumulate dust out of the child's bedroom

• Avoid stuffed toys

• Use only washable toys of wood, rubber, metal, or plastic

• Store toys in a closed toy box or chest

PETS

Keep all animals with fur or feathers out of the bedroom. If you are allergic to dust mites, you could also be allergic or develop an allergy to cats, dogs, or other animals.

Although these steps may seem difficult at first, experience plus habit will make them easier. The results-better breathing, fewer medicines, and greater freedom from allergy and asthma attacks-will be well worth your effort.