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Who Gets Asthma?

Asthma image

Asthma is very common, affect­ing more than 26 million people in the United States, including nearly 7 million children. No one knows for sure why some people have asthma and others don’t. However, heredity can play a role. People who have family members with allergies or asthma are more likely to have asthma themselves.

Asthma can occur at any age but is more common in children than adults. In young children, boys are nearly twice as likely as girls to develop asthma, but this sex difference tends to disappear in older age groups. Obesity is a newly identified risk factor for asthma.

What causes asthma?
People generally think of asthma in terms of episodes or attacks. Actually, the asth­matic condition is always present, but symptoms may be dormant until they’re triggered by an allergen, respiratory infection, or cold weather. Other triggers may include aspirin, environ­mental irritants, physical exertion, and less commonly, food additives and preservatives.

Allergens are substances that cause no problem for a majority of people but trigger an allergic reaction in susceptible individuals. Allergens are a major source of breathing problems in both children and adults. Common allergens include plant pollen (tree, grass, and weed), dander from pets and other animals, house dust mites, cockroaches, molds, and certain foods. When an allergic individual encounters one of these al­lergens, a complicated series of events causes the body to release chemicals called mediators. These mediators often trigger asthma episodes.

Environmental irritants , such as cold air, smoke, industrial chemicals, perfume, and paint and gasoline fumes, can pro­voke asthma. They probably trigger asthma symptoms by stimulating irritant receptors in the respiratory tract. In turn, these receptors cause the muscles sur­rounding the airway to constrict, resulting in an asthma attack.

Viral respiratory infections are the leading cause of acute asthma attacks. Surprisingly, bacterial infections, with the exception of sinusitis, do not cause asthma attacks. Some people who ex­perience heartburn can have asthma symptoms when stomach acid backs up into the esophagus.

Aspirin and aspirin-containing products can trigger asthma attacks in susceptible individuals.

Beta-blockers , which often are pre­scribed for high blood pressure, glaucoma, migraine headaches, and angina, are another type of medication that can cause problems. Beta-blockers can cause airway constriction, so it is important for people with asthma to consult a phy­sician about the use of these medications.

Food additives can trigger asthma; however, this is rare. The most common food triggers are sulfites, preservatives used in products such as frozen potatoes and some beers and wines.

What is the difference between allergic disease and asthma?
Asthma is inflammation and obstruction of air­flow in the bronchial tubes. Allergies are just one of the factors that can trig­ger asthma attacks. Not all people with asthma are allergic, and there are many people who have allergies but do not have asthma.


Source: American College of Allergy, Asthma & Immunology,

This article was originally published in Coping® with Allergies & Asthma magazine, March/April 2014.