Yet many sufferers don't know that pollen or other allergens are triggering their asthma attacks, knowledge that could help them breathe easier. For people with particularly severe allergic asthma, a new drug that works differently from any other asthma medicine - though it is expensive and somewhat difficult to use - may help.
"It's amazing how many people do not think allergies" despite clear patterns of wheezing, says Dr. Stanley Goldstein of the American Academy of Allergy, Asthma and Immunology.
More than 17 million Americans have asthma, a chronic respiratory disease that causes recurring episodes of wheezing, chest tightness, coughing and difficulty breathing. Every year, asthma kills 5,000 people and is responsible for nearly 2 million emergency-room visits and half a million hospitalizations.
Rates of asthma have more than doubled since 1980. Doctors aren't sure why, but allergies are on the rise, too. While asthma attacks can be triggered by numerous things - exercise, cold air, stress, viruses - roughly 60 percent are triggered by allergens.
Indoor allergens, such as pet dander, dust mites or cockroach debris, put these people at risk year-round. But outdoor-allergy season brings an increase in asthma attacks, prompting the AAAAI and the Asthma and Allergy Foundation of America to try to raise awareness of the connection.
"The symptoms are the same - you cannot tell the difference" by symptoms alone, cautions Goldstein, who directs Allergy and Asthma Care of Long Island in New York. "The distinguishing factor is, if you know you have allergies, you can definitely do more to prevent the asthma."
Everyone's airways can react to irritants, like lots of smoke. But an asthma patient's airways are supersensitive, drastically narrowing in response to minor irritants that wouldn't affect normal lungs.
It's a dangerous chain reaction: Someone with allergic asthma inhales an allergen. The immune system immediately sends out antibodies called IgE to hunt it down. IgE links the allergen to mast cells that line the nose, bronchial tubes and certain other spots, which in turn spurs the release of inflammation-causing chemicals such as histamine and leukotrienes. When those agents hit the bloodstream, they can cause not just allergy symptoms but, in someone with allergic asthma, airway swelling, too.
All asthma patients require drugs that can widen airways during an attack, and other medicines, such an anti-leukotrienes, that can help prevent attacks.
People with allergic asthma also are tested to learn just which allergens trigger their airway attacks so they can avoid them, or try allergy shots to reduce their sensitivity.
The antihistamines that clear allergy-driven stuffy noses won't help asthma.
But there is a new option for the estimated half a million people with severe allergic asthma not controlled by today's medicines: Called Xolair, it's the first anti-IgE treatment, able to cut asthma attacks by about a third by blocking the IgE-caused inflammation chain reaction.
It's expensive, between $5,000 and $10,000 a year. However, specialists say insurance companies are covering it without complaint for those who qualify, partly because of evidence that Xolair reduces hospitalizations and cuts patients' use of other medicines.
It requires shots administered in a doctor's office every two to four weeks. And so far it's just for those over age 12, although a study aiming to enroll 570 6- to 11-year-olds around the country has just begun.
While it's not a cure, Xolair provides the first opportunity to block the root cause of a breathing attack, instead of battling inflammation far downstream. With its success, now "there's a lot of heavy research focusing on the immunologic cause for that asthma," Goldstein says.
Studies by the National Institutes of Health are under way to find other treatments, such as drugs that block cytokines, another chemical involved in airway inflammation.
By Lauran Neergaard