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.
Posted in: Home Environment