The beneficial effect of a climatic treatment in children with asthma was established quite some time ago, but the mechanism of this beneficial effect has not been fully elucidated. We investigated the role of the cytokines of the TH2 pathway, reactive oxygen species (ROS) and reactive nitrogen species (RNS) over the course of a high-altitude climatic therapy.

A group of 67 children originating from various French towns suffering from uncontrolled severe asthma was sent via their medical specialists, to the Briançon climatic area. They were monitored over the course of an entire school year. During this time, they returned home for 15 days during the Christmas holidays. At each stage, assessment of asthma control, lung function examination (peak flow meter and spirometry), and measurement of exhaled NO, ROS and RNS in exhaled breath condensate (EBC), and the level of cytokines in the plasma of the TH2 pathway were carried out.

The degree of asthma control improved at high altitude and worsened upon returning home. The average value of the peak expiratory flow also improved during the first 3 months but then worsened upon returning home, while the other spirometric parameters did not change. The level of expired NO and the scores for quality of life underwent a similar change. The level of RNS and ROS in the EBC did not change significantly. Besides, a marked and statistically significant decrease in the level of IL-13 and IL-10 was noted.

The beneficial effect of a climatic stay of children suffering from allergic asthma at altitude appears to be linked with less allergenic stimulation.