What Is Cockroach Allergy?
When most people think of allergy "triggers," they often focus on plant pollens, dust, animals and stinging insects. In fact, cockroaches also can trigger allergies and asthma.
Cockroach allergy was first reported in 1943, when skin rashes appeared immediately after the insects crawled over patients' skin. Skin tests first confirmed patients had cockroach allergy in 1959.
In the 1970s, studies made it clear that patients with cockroach allergies develop acute asthma attacks. The attacks occur after inhaling cockroach allergens and last for hours. Asthma has steadily increased over the past 30 years. It is the most common chronic disease of childhood. Now we know that the frequent hospital admissions of inner-city children with asthma often is directly related to their contact with cockroach allergensthe substances that cause allergies. From 23 percent to 60 percent of urban residents with asthma are sensitive to the cockroach allergen.
The increase in asthma is not fully understood. Experts think one reason for the increase among children is that they play indoors more than in past years and thus have increased contact with the allergen. This is especially true in the inner cities where they stay inside because of safety concerns.
What Causes the Allergic Reaction?
The job of immune system cells is to find foreign substances such as viruses and bacteria and get rid of them. Normally, this response protects us from dangerous diseases. People with allergies have supersensitive immune systems that react when they inhale, swallow or touch certain harmless substances such as pollen or cockroaches. These substances are the allergens.
Cockroach allergen is believed to derive from feces, saliva and the bodies of these insects. Cockroaches live all over the world, from tropical areas to the coldest spots on earth. Studies show that 78 percent to 98 percent of urban homes have cockroaches. Each home has from 900 to 330,000 of the insects.
Private homes also harbor them, especially if the homes are well insulated. When one roach is seen in the basement or kitchen, it is safe to assume that at least 800 roaches are hidden under the kitchen sink, in closets and the like. They are carried in with groceries, furniture and luggage used on trips. Once they are in the home, they are hard to get rid of.