Food Allergies, Rare but Risky?

How Can Rhinitis Be Prevented?

Identifying and avoiding allergens can be very difficult, even with the use of allergy skin tests. Patients can, however, take some relatively simple actions to avoid the most obvious and common problems. Some studies suggest that limiting exposure to potential allergens in infants and small children may prevent allergies from developing.

Air Filters and Vacuum Cleaners. Air cleaners, filters for air conditioners, and vacuum cleaners with HEPA filters can help remove particles and small allergens found indoors. Air cleaners have little or no effect against cat allergens or dust mite feces that lodge in carpets and bedding. HEPA vacuum cleaners appear to be effective in reducing levels of second-hand smoke and preventing cat allergens from being released into the air. In one study, however, removing cat allergens from the air had no effect on asthma symptoms. Neither vacuuming nor the use of anti-mite carpet shampoo is effective in removing mites; in fact, vacuuming stirs them up. It is best to avoid carpets if possible.

Bedding and Curtains. Using semipermeable coverings to fully encase mattresses and pillows is the most proven effective step in reducing dust mite levels. (Vinyl mattress covers limit airflow and may also exacerbate, or even cause, asthma in children. Synthetic pillows may pose a significantly higher risk for severe asthma attacks in children than feather or no pillows.) Curtains should be replaced with shades or blinds and bedding washed using the highest temperature setting.

Others Recommendations. Damp housing increases the risk for asthma. On-going humidifiers then can be counterproductive because dust mites thrive in humidity, and because they can develop mold if not cleaned daily with a vinegar solution; humidity levels should not exceed 40%. Electric stoves should replace gas ovens, which release nitrogen dioxide. Cockroaches should be eliminated by professional exterminators.

Pets. Cats harbor significant allergens; dogs usually present fewer problems. If a new home can't be found or if the owner is too emotionally attached to the pet, then precautions must be taken. The pet should be kept out of the bedroom and areas where the allergic individual spends a lot of time, such as a favorite chair. Washing cats and dogs once a week can reduce allergens but it should be done by a nonallergic person and preferably outdoors. Dry shampoos, such as Allerpet, are now available for both cats and dogs that remove allergens from skin and fur and are easier to administer than wet shampoos.

Camping and hiking trips should not be scheduled during times of high pollen count (in the Northern states, May and June for grass pollen and mid-August to October for ragweed). Patients should avoid strenuous activity when ozone levels are highest, which usually occurs in early afternoon, particularly on hot hazy summer days. Levels are lowest in early afternoon and at dusk. Patients who are allergic to mold should avoid barns, hay, raking leaves, and mowing grass. Exposure to automobile fumes may worsen asthma. Fungi in car air conditioners can also be a problem.