DENVER- Black teen-agers are three times more likely than white teen-agers to have steroid resistant asthma, research at National Jewish Medical and Research Center has found.
"Our results suggest that children with steroid-resistant asthma are more likely to be African-American, to have required treatment with oral steroids at an earlier age and to require larger amounts of oral steroids for only marginal control of their asthma," said Joseph Spahn, M.D., a pediatric allergist and director of the Immunopharmacology Lab at National Jewish.
Other recent epidemiological studies have shown that blacks with asthma are sicker and have a higher mortality rate than whites with asthma. Doctors at National Jewish now are trying to determine whether blacks have a more vigorous immune response to airway inflammation--which means that higher doses of steroids must be used to control inflammation--or a poor response to steroids secondary to a genetic resistance to the drugs.
"The theory is that with ongoing airway inflammation you get worsening asthma and diminished steroid sensitivity," Dr. Spahn said.
This study of 164 teen-agers treated at National Jewish also showed that 25 percent of the group was steroid resistant. Children with less than a 15 percent improvement in lung function following a "burst" of inhaled steroids--high doses over seven days--were considered steroid resistant.
"Twenty-five percent of the kids admitted to National Jewish have steroid-resistant asthma, which is much greater than anyone thought," Dr. Spahn said.
It has been estimated that only one-tenth of a percent of the 15 million people in the United States with asthma are steroid resistant. About 5 million children in the United States have asthma.
The study, published in the Journal of Allergy and Clinical Immunology, is the first to examine steroid-resistant asthma in children.
A person with steroid-resistant asthma receives limited reduction in airway inflammation and swelling following treatment with oral steroids. Inhaled steroids are one of the main ways that asthma is controlled.
"Asthma can be a progressive disease," Dr. Spahn said. "It's really important to take medication even when you're feeling well."
Journal of Allergy and Clinical Immunology