For people who have asthma that is well controlled, changing altitude will probably not have any noticeable effect on asthma symptoms. But for people whose are sensitive to the mold Aspergillus fumigatus (A. fumigatus), spending time at a higher altitude may actually improve asthma symptoms.
Asthma is a chronic condition that makes breathing difficult. During an asthma attack, the lining of the airways becomes inflamed and swollen, and starts producing excess mucus. At the same time, the muscles surrounding the airways can tighten, which constricts the airways. All these factors combine to make it harder for air to move in and out of the lungs.
A. fumigatus is a fungus that commonly grows on dead leaves, on other decaying plants, and in soil. When the soil is disturbed, the spores can become airborne. Because of their small size they can easily be inhaled all the way into the alveoli (tiny air sacs) in the lungs. A. fumigatus is so common that scientists believe all people will inhale at least several hundred spores every day. (National Center for Biotechnology Information)
People who have healthy immune systems are typically able to get rid of the spores without becoming sick. But people whose immune systems are not healthy, such as those with cancer or leukemia, are more likely to develop a serious lung infection when they inhale the spores. Modern immunosuppressant therapies for various diseases such as organ transplants have also made more people susceptible to infection from these spores. This fungal infection can create abscesses in healthy lung tissue or can accumulate and grow in existing cavities in the lungs caused by other diseases. In severe cases, the infection can be fatal.
A group of Dutch researchers studied 170 patients who had severe asthma that was not under control at sea level. Some of the patients had a known sensitivity to A. fumigatus and some did not. The researchers took the group to the Dutch Asthma Centre Davos in Switzerland, which is located at an altitude of approximately 5,250 feet. The area is also known for its dry climate and low air pollution.
At the end of 12 weeks of treatment at the higher altitude, all the patients showed improvement in asthma symptoms. The patients who were sensitive to A. fumigatus showed an even more significant improvement in key areas. Dr. Rijssenbeek-Nouwens said, “After 12 weeks of treatment at the Davos center in Switzerland, we saw significant clinical improvement in both groups in terms of asthma control, quality of life, and lung function.”
The researchers believed the treatment at high altitude had added benefit for asthma patients who were sensitive to A. fumigatus because there is less of the fungus present in the soil in the colder and drier climate at higher altitudes. Their research may provide new insights into treatments for patients whose asthma is difficult to control.
Reviewed June 14, 2011
Edited by Alison Stanton