Roaches and Asthma : Lessons to be Learned
For many people the mere mention of the word “cockroach”makes one’s hair stand on edge. We associate these small insects with indoor dirt and decay, and we know how hard it can be to rid one’s home of an infestation of roaches once they settle in. But roaches are a fact of modern urban and suburban life. For some of us, exposure to roaches is an important cause of our asthma. For all of us, an important lesson can be learned from understanding the emerging information about the relationship between cockroach exposure and asthma.
Some people are born with the tendency to make allergic responses. Others seem to acquire the tendency along the way as they grow older. Most people with asthma have the tendency to make allergic responses in their bronchial tubes to certain things that we breath in.
This predisposition to make allergic reactions is only half the story in asthma. The other half involves exposure to those things that can elicit an allergic reaction. Certain things that we breathe in stimulate allergic responses; other things do not. Cat dander and ragweed pollen provoke allergic reactions in many people. Automobile exhaust and fog do not. To cause an allergic reaction, what we breathe needs to be of the right size and shape and composed of materials recognized by our allergic immune system.
Here’s where the unloved cockroach fits into the story. It turns out that excrement and debris from decomposing cockroach bodies are of just the right size to be lifted into the air, breathed onto the bronchial tubes, and recognized by the immune system — in certain people — as a signal to make an allergic reaction. As you know, the allergic reaction in the bronchial tubes is asthma.
Recently, a major, federally-funded research project looked for allergy producing substances in the homes of several hundred children with asthma living in several major cities across the United States. Specifically, they measured the amount of cat, dust mite, and cockroach allergen in the bedrooms of these children aged 4 to 9 years. The results were quite striking.
The most important allergen in these inner-city homes came from cockroaches. And the worst asthma was found in those children who had both the allergic tendency to make reactions to cockroach allergens and exposure to high concentrations of those cockroach allergens in their homes. Children in heavily cockroach infested homes who did not have an allergic sensitivity to cockroaches were not as likely to have severe asthma. Similarly, children who had the tendency for allergic reactions to cockroach parts but lived in homes with a low burden of cockroach allergens were also less likely to have severe asthma. It was the combination of both the allergic tendency and the allergen exposure that put the children at the greatest risk for troublesome asthma.
The lesson to be learned here is greater than just the following: If you happen to be a person whose immune system makes allergic reactions to cockroach debris, keep your home free of cockroaches. You could just as easily substitute cats or dogs or dust mites or pollens for cockroaches in the above equation. For example, if you are a person whose immune systems happens to make allergic reactions to cat dander, having heavy exposures to cat allergens will put you at increased risk for severe asthma. It appears that any allergic predisposition combined with heavy allergic exposure to those specific things to which one is sensitive fuels the fire of bronchial inflammation that we recognize as asthma.
The lesson that we learn from the study of cockroaches in asthma is this. If your asthma is difficult to control, make an effort to determine what your allergic tendencies are. If you find that you have allergic sensitivities to things in your home or work place, make every effort to reduce your exposure to those allergens. Although we cannot yet change our allergic tendencies, we can protect ourselves from breathing in large amounts of the substances to which we are allergic. By doing so, we can make our asthma better without taking a single prescription to be filled at the pharmacy.
Article Source : http://www.asthma.partners.org/NewFiles/BoFAChapter13.html