Asthma Strengthens Its Grip, Especially Among Young : Medicine: Although doctors have better treatments than ever before, they are also seeing more serious episodes.

At the end of a hot June day last year, when the pollen count was so high that you could see the feathery yellow and white grains in the air, 15-year-old Raneese Weaver had an asthma attack and nearly stopped breathing.

It started slowly, she said, as a tightness in her chest that grew bothersome by early evening. She was out of medicine, so she went to bed early, thinking rest would provide some relief.

Forty-five minutes later, she awoke, gasping for breath.

“I woke up and I couldn’t breathe,” said Raneese, 16, a District of Columbia resident. “I started crying; I couldn’t take anything in.”

Her relatives rushed her to the emergency room at Children’s Hospital, but even the doctors there, with their injections and breathing treatments, had trouble treating her wheezing. Only after a night in the intensive care unit, where she lay in an oxygen tent and got regular doses of steroids and other medicines, could she breathe clearly again.

Raneese’s case is one of a growing number of serious asthma attacks. Although doctors say they have better treatments for asthma than ever before, they are also seeing more asthma episodes requiring hospitalization and more attacks ending in death.

“It’s disturbing and quite alarming, because most of the deaths due to asthma need not occur,” said Floyd Malveaux, an associate professor at Howard University School of Medicine who specializes in asthma. “There really is no justification for it.”

During the last decade, the number of U.S. deaths attributed to asthma has nearly doubled, reaching about 4,600 in 1990, according to the National Center for Health Statistics. At the same time, the number of Americans suffering from the disease has reached unprecedented highs, rising from 6.8 million in 1980 to 10.3 million in 1990, center officials said.

Children are hit especially hard. The disease is the top cause of hospital admissions among youngsters, and those under the age of 18 accounted for about 36% of the asthma cases in 1990, according to government figures.

In addition, blacks suffer from asthma more than whites and are more likely to die from the condition’s complications, probably because many have less access to proper treatment, specialists say. According to the National Center for Health Statistics’ most recent data, asthma kills three of every 100,000 blacks and nearly two of every 100,000 whites.

The increase in asthma attacks is “a general trend, but it’s even more focused in the cities,” said Kevin Weiss, a George Washington University physician who has conducted several studies of asthma’s complications and costs. “It’s very closely linked to socioeconomic status--but even for (affluent) people, the trends are increasing.”

Asthma exacts other costs as well. A study published recently in the New England Journal of Medicine, for example, found that the disease caused U.S. children to lose more than 10 million school days a year, making it the top health reason for absenteeism from school. Overall, the study estimated that Americans spent $6.2 billion on asthma in 1990, in hospital care, medications and missed days from work.

Most people with asthma usually breathe normally. But the small airways in their lungs can suddenly narrow and become clogged with mucus and other secretions. The process reverses itself eventually, but in some cases the blockage may become so severe and the process of clearing may take so long that the person suffocates if help isn’t provided.

In some very rare cases, said Michael Sly, a professor of pediatrics at George Washington University Medical School, patients have died within 20 to 30 minutes after their symptoms began.

What triggers the asthmatic reaction varies. In the most common type, the asthmatic patient also has allergies that cause a reaction when foreign materials or allergens, such as pollen, dust or animal dander, enter the body.

The immune systems of some asthmatics produce excess amounts of an antibody protein called immunoglobulin E, or IgE, to protect the body. IgE binds to cells called mast cells, which are frequently found under the skin and around the airways. The IgE can then make the mast cells release histamine and other substances.

For people with some allergies, the substances can trigger a hay-fever attack, sneezing, watery eyes or a runny nose. For an asthmatic, the response is more dramatic.

The histamines can cause muscles in the airway to constrict and can attract fluids and other cells to the site, clogging the airways. It leads to the wheezing and shortness of breath that, if unchecked, can threaten a patient’s life.

This type of allergy-related asthma tends to be more common among younger people, many of whom may outgrow it, and often runs in families. It is frequently worst in late spring and early summer and fall, when trees and grasses spew their pollen.

Researchers at the National Institutes of Health estimate that about 90% of asthmatics under age 10 have this sort of asthma, compared with about half of asthmatics over age 30.

Other asthmatics have attacks after being exposed to chemicals, such as compounds found in paint and gasoline fumes, that may directly irritate special receptors in the airways. Or they may get attacks after infections, after exercise or after eating certain foods, for reasons scientists don’t completely comprehend.

People with asthma also may be at greater risk of having attacks during stressful times. But although the association between these triggers and asthma attacks has been firmly established, “from a practical point of view,” said James McCormick, a professor at the University of Massachusetts Medical School who specializes in lung diseases, “the mechanism by which stimuli like stress (affect asthma) is completely unknown.”

Armed with their understanding of what triggers asthma attacks, scientists have come up with a variety of theories about why asthma is increasing. But there is little proof for most of the explanations.

“There’s no consensus, and nobody has the answers,” said Mary White, an epidemiologist in the air pollution and respiratory health section of the federal Centers for Disease Control in Atlanta. “My own sense is there’s no one right or wrong answer but . . . they are operating simultaneously.”

According to one widely held theory, asthma has increased because improvements in insulating offices and homes over the last 20 years may have resulted in the trapping of asthma agents indoors.

According to another theory, smoking among mothers may also be responsible for some cases of asthma among children. Scientists don’t know exactly how tobacco smoke interacts with the lungs of the developing fetus and young children. But studies have suggested children as young as 18 days old whose mothers smoke have airways that are more likely to contract than those of babies of non-smoking mothers, said Sonia Buist, a specialist at Oregon Health Sciences University in Portland.

Others believe that high levels of outdoor air pollutants, particularly ozone, are to blame, but this idea is controversial.