Effect of sustained high altitude on asthma patients.

Due to factors such as allergen avoidance and the decrease of air pollution, sustained stays in a high-altitude climate have been recommended for asthma patients for a long time. There are also documented effects and favorable influence on the health of permanent residents at high altitude; for example, the frequency of allergic sensitization to house dust mite in asymptomatic subjects is much lower than at sea level. In the context of this article, 'high altitude' means 1500-2500 m above sea level. The aim of the review is to summarize the available data on the effects of a sustained stay of asthmatic patient data between 1500-1800 m above sea level in alpine altitudes (Europe). Climatic conditions in South America or in Africa are completely different from the altitudes discussed in this review. We conclude that the available evidence suggests a significant benefit of high altitude for asthmatic patients, particularly in steroid-dependent patients.