Allergy Handbook

Allergy and The Environment – An Arizona Handbook

The Arizona Allergy and Asthma Society is an organization comprised of board-certified and board-elligible Allergy/Immunology specialists in Arizona. One of our goals is to serve as a resource for allergy information to the Arizona public. This is achieved by providing Arizonians with the “Allergy and the Environment, An Arizona Handbook.” On online version of this handbook is available below.

Home Environment

Which is better – air conditioning or evaporative coolers?


by Bryan Updegraff, M.D.

The importance of controlling the environment in the home has been emphasized elsewhere. It is vital to the allergy patient’s attempt to relieve symptoms. Controlling the air that enters the home is the most important factor in this equation.

We emphasize to patients that closing the windows to keep the pollen, dust, and mold out of the home is vital. Air conditioners are preferred over evaporative coolers in general, because they recirculate the air, which can be cleaned. Air can then be filtered either at the source by a central HEPA filter system, at the ducts, or later with free-standing units.

Unique to Arizona is the efficiency and popularity of evaporative coolers. These systems are less expensive to run and have the added benefit of not excessively drying the air, so that allergy patients who have sensitive, dry skin can feel more comfortable. They have the disadvantage of introducing into the home outside air which is more or less filtered, depending on the status of the pads in the system. The traditional padding is the so-called aspen filters. This is aspen wood, which may be quite thin, and does a poor job of filtering particles. As these systems age they may not totally be moistened and then, essentially are non-existent filters. They expose the patient to the environment he is trying to avoid.

Recent improvements in evaporative coolers use a single inlet system and an improved filtering system based upon a cellulose (almost cardboard) material which is thicker than aspen pads. It is claimed that these filters can actually filter out substances down to 10 micron size, and represent a significant step forward to those individuals who would like to use evaporative coolers.

Whatever system you choose needs to be well maintained. Evaporative systems should be checked by maintenance people and the air conditioning system’s filters can be changed frequently.

What are the benefits of an air purifier?


by James Dover, M.D.

Allergens and air pollution can best be treated by avoiding exposure to them. This can be accomplished by correctly designing the bedroom exposure, and by using air purifiers to reduce exposure within the home.

Air purifiers come in all shapes and sizes, and can use one or several collection techniques. What really counts is not their appearance, but their effectiveness in cleaning the air where you need it cleaned and to the degree it needs to be cleaned. The commonly asked question is which one is best: a single portable room air purifier or one installed in the home’s central heating and cooling system.

Approximate efficiencies of central furnace filters:

  • Standard furnace filters – 5%
  • Electrostatic filters – 75%
  • Electronic filters – 95%
  • HEPA filters – 99.75%

A highly efficient HEPA filter, high CFM (cubic feet per minute) portable, will be more effective in the room where it is located than a central system. There are scenarios that can go either way, but the portable unit has some features not available with a central system, such as:

  • Usually less expensive than an efficient installed system.
  • Can be moved with the people to do a superior cleaning job in the room where time is spent.
  • Can “visit” friends, relatives, office, or motel.
  • Can move with the family to a new home more easily than a central system.
  • Can have a lower electrical operating cost, considering the large heating/cooling blower must be operated continuously with central cleaning.
  • There are no installation costs involved with portable units.
  • Can filter our odors or chemical smells better due to carbon filters that are replaceable.

Remember to look for this information when selecting your air purifier:

  • CFM. Cubic feet per minute tells you how much air can be cleaned each minute. The larger the CFM rating, the larger the area cleaned.
  • RSP. Respirable size particle is measured at 0.3 micron, which is the range most likely to be deposited in the lungs.
  • CADR. Clean air delivery rate measures the volume or air that is moved through and treated by the purifier. If no air moves through a 100% efficient air purifier, the effect is no air cleaned. An air purifier with a larger CADR number can always maintain cleaner air in a space or room than one with a small CADR, regardless of the size of the room.
  • Warranty. Most quality units have a lifetime warranty for central units and replaceable filters for portable units.

Above all, do not waste money on cheap products which deliver insufficient airflow, require frequent service or filters, or may be poorly constructed.

Can the right vacuum cleaner help reduce allergens in the home?


by Earl Labovitz, M.D.

Avoiding and removing dust from the home environment is a challenging and ongoing problem allergy sufferers face on a daily basis. In the southwest, desert winds sweep loose topsoil into the air, carrying inorganic and organic substances including pollen grains and mold spores. Some of this dust and dirt is transported into our homes by air currents, as well as by people and their pets. Carpets become the storage compartment of that dirt and dust, dust mites (especially in humid environments), as well as animal hair and dander, and insect body parts (crickets, cockroaches, and silverfish). Keeping the carpet, other floor surfaces, upholstered furniture, curtains, and blinds clean is a monumental task, but most important is keeping the allergic and asthmatic patient well. Removing the dust will also reduce the need for some medications and improve the quality of life indoors for the allergy sufferer.

Now that we understand vacuum cleaning is necessary for the removal of dust from surfaces of carpet, choosing the right one may be complex and confusing. Many models and types are on the market for sale and marketed as “hypoallergenic.” A water filtering system was compared to a HEPA (High Efficiency Particulate Air) vacuum. There was significant reduction of allergens in the carpet from vacuuming with the HEPA-filtered vacuum without any increase in airborne particles; however, there was an increase of cat allergen airborne particles when the investigator used two different brands of water-filtered vacuum cleaners. It was the opinion of several of these investigators that a tight connection between hose and bag and a double- thickness dust bag (or multi-layered bag) are the most important factors in limiting leakage from canister vacuum cleaners. An efficient filter at the exhaust outlet is also very important in reducing dust particles and airborne cat allergens.

Some allergists recommend HEPA vacuum cleaners such as Nilfisk or Miele vacuums which have minimal leakage and high allergen containment. The HEPA filtration prevents particles from escaping through the exhaust. They both have very high waterlift measurements which provide thorough removal of dirt and allergen from carpet. Other allergists recommend commercial type vacuum cleaners, such as Advance or Windsor, with special thick or multi-layered bags, as well as exhaust and intake filters. These are both powerful and durable. Smaller width heads may be used for the home. All of the above-named vacuums may run between $500 and $700.

But for those patients who do not wish to invest in a new vacuum cleaner, one can greatly improve the performance of their existing vacuum cleaners simply by using multi-layer bags or microfilter bags which can more than double their cleaning ability. These bags may be used for Electrolux, Eureka, Hoover, Oreck, Kenmore, Sharp, and Panasonic brand models. Also electrostatically-charged filter media (Vacu-Filt vacuum exhaust filter) will greatly aid in decreasing the escape of allergens from the vacuum cleaner prior to exhaust. Both products are very affordable and adaptable to most vacuum cleaners. You may consult your allergist for an opinion about these products for your home use.

Do you need to be concerned about house dust mites?


by Linda Alvarez-Thull, M.D.

Do you need to be concerned about house dust mites? Are these mites making your asthma or allergies worse? If so, how can you get rid of these creatures?

House dust mites (scientifically called Dermatophagoides pteronyssinus and D. Farinae) are microscopic mites that live in beds, carpets, sheets, sofas, and other furnishings or material that hold moisture. These scavengers feast on dead skin which is found in house dust. Dust mites are one of the most important allergic substances found in house dust. The essential ingredient for the livelihood of the mite is humidity. Generally, those environments in which humidity reaches 50% or more are the best habitats for these mites. If humidity is lacking, these creatures dry up, die, and eventually may become non-existent in a dry environment. In areas of the country where humidity is relatively high such as the southeast and east coast, house dust mites are ever-present, and very difficult to eradicate.

Exposure to this year-round allergen is responsible for much exacerbation of asthma and hay fever problems. In a person with asthma or an allergic predisposition, significant improvements may occur with dust mite control in the home. Extreme (but possible) measures must be taken to eradicate this allergenic hazard from the home. Measures include encasing mattresses, pillows, and bedding with impermeable covers, washing sheets in hot (130 degrees) water, selecting furniture with impermeable coverings such as leather, and choosing tile or wood floors as opposed to carpet. Chemicals that break down the allergic particles of the dust mite, or cause their demise, are available for the home. The most important measure is to maintain low humidity in the home.

So, do inhabitants of Arizona need to worry about house dust mites, since we supposedly live in a dry environment? Perhaps. Let’s take an example from a study done in Denver, Colorado, which is reportedly a low-humidity environment. Homes that used evaporative coolers were sampled for dust mites. These homes surprisingly had a measurable level of dust mites that was within the range for causing allergic problems. No formal study has been done in Arizona. However, it is likely that homes that use evaporative coolers on a consistent basis may support dust mite growth. In addition, humidity in some areas of Arizona is increasing due to increased moisture released into the air through irrigation and by air conditioners. Keep in mind also that dust mites may live as long as six months in furnishings brought in from humid environments.

What recommendations can be offered? If someone in your family has asthma or an allergic problem, taking measures to dust mite proof your home may not only eradicate a potential problem, but give you peace of mind that these pesky creatures are not hampering your health. Speak to your allergy specialist about your particular situation.

Do cockroaches and crickets affect allergy sufferers?


by Michael E. Manning, M.D.

Allergens – substances that individuals can become allergic to – are typically classified as external or outdoor allergens, such as pollens, or indoor allergens, such as dust mites, animal danders, or cockroach allergens. Cockroach allergens have gained increasing attention in recent years as one of the most important indoor allergens in the development of asthma, and possibly allergic rhinitis, or hay fever. Arizona does not seem like a place where cockroaches would be a problem, but it is.

Although there are thousands of species of cockroaches, only about ten have been shown to adversely affect humans. The species occurring most commonly in U.S. homes include the German, Oriental, and American cockroaches. The American and Oriental cockroaches can live not only in houses, but in sewers and outside habitats near homes. The German cockroach rarely survives outside buildings.

Cockroaches have four requirements to live. They are food, moisture, warmth, and refuge. It is understandable, then, that studies have shown the highest levels of cockroach allergens to be on kitchen floors and in kitchen cabinets. Just because your home seems to be cockroach-free does not mean you are free of cockroach allergens. Studies have shown that at least 20% of homes felt to be cockroach-free had significant levels of cockroach allergens. Therefore, even if you think you do not have a cockroach problem, thorough investigation may be necessary. The cockroach allergens are felt to come from the body of the insect, along with their fecal material. If a cockroach dies and its body breaks down, this, along with the fecal material, can become part of the house dust. That means you do not have to see the cockroach in the room for it to be bothering you.

Another insect, similar to the cockroach, is the cricket. Crickets are prevalent in Arizona and easily find their way into homes. There have been no well-controlled studies looking at the prevalence of cricket sensitivity, but they have been identified as a source of inhalant allergen. There is no standard testing material. However, avoidance measures would be the same as with the cockroach.

Determining if one is sensitive to cockroach starts with a careful history, and if appropriate, specific skin testing. If you are found to be sensitive to cockroach, the treatment options are threefold. First, avoidance measures need to be instituted. These would include thorough housecleaning, keeping food stored properly, and using an exterminating service. If the problem still exists, medications can be used, depending on the symptoms. The last option is immunotherapy or allergy shots. However, with cockroach, there are no well-controlled studies supporting this as an effective treatment, and therefore, it is difficult to recommend.

How does low humidity affect allergy sufferers?


by Gerald B. Goldstein, M.D.

Most of us in Arizona are much enamored with the dry hot climate here in the southwest. In fact, many people move to this area for the beneficial effect of the climate on their respiratory disease and arthritis. However, as the old adage goes, one man’s meat is another man’s poison, and that seems to hold true for climate as well. Over the years, I have seen many patients where low humidity is a contributor or is the sole cause for symptoms relating to the skin, eyes, and respiratory system. I would like to discuss some of these problems briefly, as well as to mention some of the measures that may be taken to help with relief of discomfort.

The Skin

Dry, flaking, itchy skin is a common problem in Arizona. The medical name for the condition is xerosis, and elderly people are affected most often. The term “winter itch” has been coined because the dry heat from the furnace in winter lowers humidity further and accentuates the problem. Dry and itchy skin may sometimes cause intense scratching, bleeding, and infection. The most helpful treatment is to apply moisturizer ointments such as Eucerin and similar over-the-counter preparations. Moisturizers may be applied any time of the day or night, but they are most effectively used following a bath. If skin inflammation is present, your doctor may wish you to apply a steroid cream to the skin as well.

The Eyes

Although there may be some itching associated with dry eyes, the main complaints are those of burning, tearing, and a sensation that there is sand or dirt in the eyes. Eye discomfort accentuated during windy weather which causes more evaporation of the tear layer. Patients with contact lenses are particularly uncomfortable. Dry eyes do not respond well to allergy drops, but will improve with artificial tear lubricants such as Tears Natural, Bion, and Hypo Tears, to name a few. Avoid being out during windy weather, if possible. A humidifier in the bedroom at night and in the office during the day may help as well.

The Nasal and Sinus Cavities

Presenting symptoms in this case may include dry, burning nasal passages with crusted nasal secretions, and sometimes nasal bleeding. Other discomfort includes thick post-nasal discharge and headache in the sinus areas. Moisture serves to protect the nose and sinuses, so that patients with dry membranes are more susceptible to nasal and sinus infection. One often hears that patients feel better when exposed to the humidity of a shower or in a steam room, and they also are improved when visiting damper areas of the country. While air conditioners act as humidifiers, evaporative coolers are better for nose and sinus conditions because they add moisture to the air. A bedroom humidifier may need to be used at night for most of the year, and saline nasal washes should be used often during the day. The older antihistamines with their drying properties should be used sparingly or not at all.

It should be noted that the above low-humidity problems may be present alone or in combination with typical pollen, mold, or animal dander allergy. If the patient is to be optimally comfortable, then both conditions need to be addressed. Unfortunately, fighting the climate is a difficult task, but most people can derive improvement if they are consistent in adding humidity to their environment where and when it is needed.

How does humidity affect me?


by Geraldine Freeman, M.D.

Humidity is the amount of moisture in the air. Relative humidity is given as a percentage: the amount of moisture in the air relative to the greatest amount that air could hold. It can range from completely dry air, 0% relative humidity (say, in the Sahara Desert) to saturated air at 100% relative humidity (fog, a rainstorm, or a wet day in the tropics). Warm air can hold more moisture than cold air, so if you bring cold winter air into your house and warm it up, the relative humidity goes down. The air becomes effectively drier, and will draw moisture out of the surroundings – including the people in the house. The more you heat the air, the drier it behaves.

Extremely dry air is uncomfortable. It pulls water out of the skin, eyes, mouth, nose, and throat. A reasonable humidity level will provide more comfort. Humidity can be added to a home by way of small humidifiers, or a humidifier installed on a central heating unit. On the latter, there should be a humidistat to keep the moisture level at about 35%. Freestanding console humidifiers can increase the humidity of a whole house, while small humidifiers or “misters” can raise the level in a room. Sometimes a small humidifier, as in a child’s bedroom, will raise the humidity excessively, dampening the room and promoting the growth of mold and house dust mites. Avoid hot water humidifiers, which can be tipped over, sometimes burning children. Keep any humidifier meticulously clean and maintain it according to the manufacturer’s instructions, to prevent an unhealthy and dangerous growth of mold and bacteria.

A kettle of water on the kitchen stove or a wood stove does not introduce any significant humidity into the home.

In warmer weather, when an air conditioner is running, it raises the humidity, sometimes so much that excess water condenses and drips off of the unit. Adding moisture then is unnecessary, and will only make the air conditioner work harder. Evaporative coolers, of course, produce moist air which does not need any additional humidification.

Should I move? And if so where?


by William F. Morgan, M.D.

Many people move to Arizona in hope that their allergies will improve or go away. This advice is often offered by their physicians or friends. However, there are very few scientific studies which address moving to help allergies or asthma.

In 1971, J.M. Smith published a paper in The Journal of Allergy and Clinical Immunology titled “The Long-Term Effect of Moving On Patients with Asthma and Hay Fever.” Several interesting points are made about patients moving from the Midwest to either the western or eastern United States. Patients moving west reported themselves as promptly all or much better 75% of the time. An additional 8% reported gradual improvement. Patients moving east reported themselves as promptly all or much better 29% of the time, and 41% showed a gradual improvement. If there was improvement after moving, the improvement was usually maintained over the years. However, many of their relatives, usually children, reported the development of allergies in the new location.

My observation is that patients who are sensitive to ragweed in the East, Midwest, or wherever, will continue their ragweed allergies in Phoenix. Because of the drier climate and less rainfall, there is not nearly as much pollen as in rainier climates. This is especially true when Phoenix has droughts during the spring and fall months. However, the mild winters and spring and fall months lead to year- round symptoms for many.

Finally, all large cities are plagued by smog. Phoenix is no different. Our increasing smog is leading to more irritant-like allergy symptoms.

There is a shorter pollen season above 5,000 feet. Many allergy patients do well in Flagstaff, Payson, Prescott, etc.

Patients with asthma triggered by non-allergic factors have asthma all year long. They will not be affected by the local pollen. Non-allergic factors include viral illness, smog, weather changes, exercise, and odors.

In summary, many factors are involved in allergies and asthma. Moving may solve some pollen allergies, only to allow other factors like smog to play a larger role. Patients with severe problems are not usually totally cured by a move.

Allergy and the Environment