What I Can Do
If your sneezing and stuffiness come and go with the seasons, chances are good that you are sensitive to pollens. Symptoms in February through April mean that tree pollens are the most likely culprit. Grasses tend to pollinate heavily in May and June. Weeds primarily pollinate from late summer through Fall. Toward the end of a season very small exposures can perpetuate alleric respiratory disease.
Since no one wants to remain indoors all the time, avoidance of airborne pollens can be difficult. Pollen grains can drift inside with or without a breeze, so it is very important to keep the windows closed during the pollen seasons. If you are allergic to the tree outside your bedroom window, either remove it or never open the window during its pollinating season. If you are allergic to grass pollen, you should not be in the yard when the grass is cut and pollens are thrown into the air in high numbers. Also, remember that cats and dogs can bring pollens into your home.
HOUSE DUST MITE
There are many components in house dust to which people may be allergic, but the most important is dust mite. This is a microscopic, insect-like relative of ticks and spiders that is found in homes. They are invisible to the naked eye and live primarily in mattresses, carpets and upholstered furniture. They thrive in humid and warm conditions, pillows, bedding. Low humidity inhibits them. Their diet consists of shed scales from human skin. Amazing or disgusting as it may seem, the main substance that provokes allergy symptoms is the fecal waste particle of the dust mite. These particles continue to cause allergic symptoms even after the mite has died. Fragments puff into the air we breathe.
The greatest source of dust mite exposure in the home is the sleeping area (mattress, pillow, bedding) which provides the best conditions of warmth, humidity and food for their growth.
Scientific studies of dust allergic patients have shown that taking steps to minimize dust mite exposure in the bedroom leads to a decrease in allergic symptoms and a decrease in medication requirements. Emphasis is placed on the bedroom, since people spend one third or more of each 24 hours there, and because it is the room with the greatest number of dust mites.
Control measures include:
- The mattress, box spring and pillows should be encased in zippered, dust-proof covers. Vinyl covers will work, but special covers that "breathe" by allowing the passage of water vapor while blocking the escape of mite allergen will prove more comfortable.
- Avoid feather or wool blankets and wash all sheets and blankets in hot water every week.
- Remove curtains, upholstered furniture and stuffed toys from the bedroom.
- Eliminate carpeting from the bedroom. If this is not possible, use commercially available products to kill mites or eliminate their allergen in carpets. Carpet Treatments: Acarosan (Benzyl Benzoate) Powder kills dust mites and Allergy Control Solution [Tannic Acid (3%)] Solution partially inactivates the allergenic protein. Neither have long term effects and must be used repeatedly.
- Keep humidity below 50% by using air conditioning in the summer and dehumidifiers if necessary. Dust mites die at humidity levels less than 50 percent.
Molds or fungi produce spores even smaller than pollen grains. These are found in the air in large numbers and cause allergic reactions in patients sensitive to them. Their growth is encouraged by warmth and high humidity so they are most prevalent during the humid seasons of the year. In the South, where the weather is warm and humid much of the year, molds can be found in the air throughout the year. Molds are found outdoors in and on anything organic (soil, grass, dead leaves, haystacks, barns and stables). They abound in damp cellars, closets, attics, and rooms that have been sealed off, where they are responsible for the musty odor typical of such places. They are often found in the crawl spaces beneath houses. Molds are frequently present in furniture and mattress dust. They attack paper products such as wallpaper, wallpaper paste, paint, wood, natural and synthetic fibers, and leather. They have been found on rubber gaskets around refrigerator doors. Potted plants and soil will breed molds. Cut flowers can become contaminated before they are brought in the house. Patients allergic to the mold penicillium are not necessarily allergic to the drug penicillin.
Prevention of Mold Growth
Mold is the green growth on a damp window sill or cheese, the dark growth between your bathroom tiles, the bad smell in the old damp footwear and the mildew found in damp areas or on clothes. Mold travels freely and invisibly through the air and may be responsible for allergy when inhaled.
Mold needs dampness for growth, so keeping the house dry is important. A dehumidifier may be useful. Repair of a leaky roof or damp basement can help. Several companies make a silicone-rubber seal which can be used to seal cracks. The basement should be heated and well-lighted in winter, well-ventilated in summer.
Mold growth is retarded by removal of obviously moldy items from the house, e.g., damp carpets or pads, rubber products, camping equipment, mattresses, stored vegetables, fruits, grain, books, flowers or Christmas trees. The drip pan under the refrigerator should be cleaned periodically and sweaty pipes should be covered with insulation. Evaporative coolers can also grow mold on their filters and should be replaced with refrigerative coolers if possible or at least clean the filters regularly.
Other items that appear moldy but cannot be discarded (e.g. humidifiers, air conditioners, vaporizers, etc.) should be treated with mold inhibitors. Excessive use of humidifiers should be discouraged since its use can lead to mold growth on wallpapers and walls. Molds may grow within the humidifier and therefore it can also serve as a dispersion source of mold.
Bathroom walls steaming from frequent showers may also lead to growth of mold. Therefore damp bathroom areas should be vented to dry after showers. The soil pot of the household plants may be covered with aluminum foil to decrease the dissemination of mold spore from the soil by air currents. The practice of keeping damp clothes in the washer for prolonged period should also be discouraged.
If mold is in the plaster or wall board, then plaster or wall board should be sealed with shellac or varnish and then painted with a mold resistant paint.
If you are purchasing a house, then homes which need sump pumps or have basements with water level marks on the walls indicating previous flooding should be avoided. If building a home, urge home builders to put sheets of heavy, black polyethylene under the basement foundation and outside foundation wall to prevent leakage and mold problems. Installment of moss-rock fire places should be avoided. Wall papering should be limited, especially those of grass cloth and burlap papers.
A mold resistant paint, Loxon, is manufactured by Sherwin-Williams. In addition to the use of such paint for moldy plaster, it can also be useful for basements. Painting of moldy surfaces with Dowicide or Captan (1 tablespoon per quart of paint) also resists mold. Zepharin chloride can be used to prevent the growth of mold in the humidifiers. It can be purchased from the druggist and should be diluted as the package directs (1:750). Zepharin chloride can also be sprayed around the house, taking care not to damage lightly varnished or finished furniture.
Other products that may be used in damp areas to retard mold include Captan, Impregon and Bye Mold. Captan is available at garden supply stores. Four ounces of the powder is mixed with a gallon of water. This can be sprayed in closets and other damp rooms and may prevent mold growth for months. Impregon can also be sprayed. It is prepared by adding one teaspoon to a gallon water. A Windex sprayer can be used. Weekly spraying is advisable. Impregon can be added to the last rinse cycle of the wash.
Central air ducts may harbor molds which disseminate freely through the home. If a musty smell is noted when air flow begins, consider professional inspection of the air system. Studies have shown that professional air duct cleaning can substantially reduce mold content of indoor air.
ANIMAL HAIRS & DANDERS
Indoor pets are a common cause of allergy. An estimated six million Americans are allergic to cats. Allergy to dogs is less common but still significant. Despite claims to the contrary, there is no such thing as a nonallergic breed, although some individual animals do produce less allergen than others of the same type. In the case of cats, the allergen is not the hair, but a protein present primarily in the dander and saliva of the pet. These allergens become airborne as microscopic particles that remain suspended in the air and may cause symptoms even when the pet itself is not present. Household reservoirs such as mattresses, carpet, and furniture may contain pet allergens for years.
The following steps have been proven to decrease exposure to animal allergen.
- The best situation for a person allergic to animals is to not have a pet. Even homes with outdoor pets have greater amounts of indoor pet allergens. If this is unacceptable, the pet should be kept strictly out of the bedroom and limited to as small an area of the house as possible, preferrably an area with no carpet or upholstered furniture.
- Ventilate the house to allow airborne animal allergen to escape and fresh air to enter. Tight "energy efficient" homes allow allergen to build to high levels. A good quality HEPA (high efficiency particle-arresting) air cleaner will reduce airborne animal allergen levels considerably if used in a small enough area. Do not expect large rooms to be handled adequately with these types of filters.
- Bathe the pet every 1-2 weeks with plain water. This removes a surprisingly large amount of allergen and decreases future allergen production. Remember, pets that live both indoors and outdoors may bring outdoor pollens into the home. These pets may require more frequent bathing. Cats do not mind being washed if bathing starts when they are kittens or if they are introduced to it gradually.
- Cat allergen clings to soft materials such as carpets and mattresses for months or years. Remove bedroom carpet (when possible) and encase the pillows and mattress with a dust-proof cover. An alternative to removing the carpet is the use of a commercially available tannic acid solution that inactivates cat allergen in carpets. This will only be useful, however, if the pet is not allowed back into the room.
Ideally there should be no animal pets with fur at the home of an allergic patient. If you have no such pets, do not acquire them. The relative importance of removing a family pet from the home of an allergic patient must be guided by the degree of sensitivity to the danders produced by that pet and the severity of allergic disease. Wherever fur-bearing animals live, the dander or dandruff from their skin accumulates in the surrounding environment and circulates in the air. These allergens can in some instances cause life threatening allergic reactions, particularly for patients with asthma. Animal danders may also be carried into the home even though the animal stays outside. For example, patients who are allergic to horses must avoid not only horses and stables but also persons or objects directly or indirectly connected with the handling of horses. For example, contact with clothes worn for horseback riding may cause as much trouble as direct contact with the horses. Members of the family who ride or work with fur-bearing animals should change their clothes and wash themselves carefully before returning home.
You should seek out these allergy troublemakers and try to avoid exposure within the home at least. If allergic sensitivity has already developed to any of these animal allergens, the importance of minimizing exposure is obvious. It may take up to six months for animal allergens in the home to reduce to insignificant levels after pet removal. Secondly, the chance of developing allergy to these biologic particles can be substantially reduced by limiting exposure. This does not mean that patients with inhalant allergy cannot enjoy horseback riding and outdoor pets, but it would not be recommended for a patient with significant animal inhalant allergy to engage in a career in veterinary medicine or livestock farming and industry.
Population studies show that infants brought into a home with multiple indooor pets, especially cats, may experience a reduced tendency to develop allergies and asthma during school-age years.
Allergy to feathers is common. Within your home feathers are most commonly present in pillows. Through natural degradation, small allergen particles from feather pillows mix with house dust and aggravate feather-sensitive patients. The best pillow for an allergic patient is made of synthetic fibers such as polyester, dacron, acrilan, or dynel. Sponge rubber pillows are less desirable because they may promote mold growth. If you wish to use feather pillows, they should be 100% covered with a rubberized or vinyl encasing with zippers. There should be no feathers, down pillows, or down comforters anywhere in the house. Avoid everything stuffed with feathers. If you are allergic to feathers, do not allow any feathered birds in your house. Don't use a feather duster.
Cockroach allergy is surprisingly common. These insects leave eggs, droppings, and bodily remains which disintegrate and eventually may become airborne causing respiratory allergic disease. Cockroaches may be very difficult to get rid of, particularly for those living in a large apartment building or attached dwelling. Additionally, it is necessary to thoroughly clean kitchen and bathroom cabinets to remove cockroach allergens. For cockroach extermination, we recommend calling a professional. If you know of an innovative method for dealing with these pests, please let us know and we will pass it on.
Usually food allergy causes clear cut symptoms easily diagnosed by the patient. Occasionally food allergy may cause chronic symptoms which are not easily attributed to a specific food. If skin tests for foods were performed and found to be negative, there is very little chance that food allergy is responsible for chronic allergic symptoms. Since there can be false positive reactions to food skin tests, any food that gave a positive reaction on the skin test should be removed from the diet entirely for a period of ten days. It should then be reintroduced in a large amount and careful observation made to see if there is any flare up of the allergy symptoms. If not, then there is no true allergy to that food and it may be kept in the diet. If you can demonstrate on two occasions that the food does produce symptoms, then obviously it should be eliminated from the diet thereafter. Foods should not be removed from the diet based only on the skin tests without eliminating it and rechallenging as described above. Allergy shots for foods are currently not available.
Exposure to pollutants and chemical irritants magnifies the allergic person's reaction to allergens. It is not unusual for the level of air pollution to be higher indoors than out.
Do the following to decrease indoor pollution:
- Prohibit smoking indoors. Secondhand smoke exposure worsens all symptoms of allergy.
- Use an exhaust fan when cooking with a gas stove.
- Ventilate the house to allow any chemical irritants produced indoors to escape. This is especially important in mobile homes where formaldehyde is used in the construction. New carpets will also produce at times a significant irritant effect and thus adequate ventilation is essential.
- Avoid exercising outdoors on high pollution days.
Studies to assess the benefit of air filtration for allergy sufferers have shown disappointing limited results. These devices are not routinely recommended but in some cases may provide benefit. Some guidelines are provided below.
Intake vent filters are inexpensive filters that cover the incoming air vent for central air conditioning and heating systems. They are designed to minimize all kinds of airborne allergens from entering the duct work. Although not as efficient as a HEPA filter, they are a good place to start. The cheaper filters do an acceptable job, but must be changed every month. The more expensive filters suggest that they can last up to 4-6 months, however, many times they become occluded after a few months due to the trapping of a large amount of particles and therefor should be replaced more often. The smaller the size of the filtered paticle, the more allergens will be removed from the air.
HEPA (high efficiency particulate arresting) Filters are the recommended air cleaners for individual rooms. They are effective at removing dust mite allergen, pollen, mold spores and dog and cat dander. They filter 99.97% of particles down to 1/3 micron in size (pollens average 15 microns). Many manufacturers make HEPA filters so it is important to look for a filter with at least 200-250 CFM power. (Cubic Feet cleaned per Minute) Despite having a HEPA filter, these units will only clean medium to small rooms. Studies have shown that they are most effective for reducing symptoms when they are used to clean air in the bedroom and that the efficiency is reduced when used to clean large areas in the home.
Electrostatic "Whole House" Air Filters are central air/heat filters that are used in place or regular disposable filters. When they are clean, they are more efficient than regular filters and do not have to be replaced. Although not as efficient as a HEPA filter, they do cover a large area. However, they can only filter if the fan is running on the central air system. They must be cleaned regularly and thoroughly to be of optimal benefit. The built-in "electronic" air cleaners are different in that they are separately powered and generally sold by heating and air companies. They charge (or "zap") the particles and make then adhere to oppositely charged metal plates. The problem is that these plates become covered over very quickly and then no more zapped particles can adhere to them. The efficiency is lost in 20-30 hours of use. Unless the plate is washed at least weekly (instead of the "recommended" monthly or quarterly) little or no filtering will take place. These units are expensive, so discuss it with your allergist before investing in one.
Immunotherapy, or allergy shots, are indicated only for the treatment of allergy to those things which cannot be avoided. This includes pollen grains, mold spores, house dust, and sometimes cat. Ideally, individuals with pollen allergy should keep all windows and doors closed 24 hours a day during the pollen season to keep pollen out of the house. An attic ceiling fan pulls pollen into the home through open windows and should never be used.
Allergy shots contain the specific pollens, molds, and/or house dust found positive on skin testing. The concentration and dosage is initially small and increases at weekly intervals up to a maintenance level. By doing this, one can usually build up a tolerance (desensitization) so that the body can withstand a larger and larger exposure to these allergens without producing troublesome allergy symptoms. At no time should the shot cause a flare up of the underlying allergy problem, nor should the shot make a red, swollen place on the arm larger than a silver dollar or a walnut. Occasionally some patients experience a small swelling or mild itching at the site of their allergy shot. In those few cases where local reactions become troublesome, the concentration may be reduced to eliminate this problem. In the long run it is the total amount of allergen which is injected which determines the degree of benefit.