High altitude and asthma: beyond house dust mites

Abstract

In this issue of the European Respiratory Journal , Rijssenbeek-Nouwens et al . [1] demonstrated that the benefit of a stay at high altitude was comparable in allergic and nonallergic adult asthmatic patients (allergy was defined on the basis of specific immunoglobulin (Ig)E to a panel of common aero-allergens). This benefit was substantial, exemplified by a discontinuation in oral steroids intake over the course of the stay in about 40% of both groups of asthmatic patients and an average reduction of 50% in the other patients. The causality of the relationship between decreased exposure to house dust mites (HDM) allergens and asthma control in HDM-allergic patients is indicated through the following evidence: HDM allergen level decreases as altitude increases, apart from in humid climates; asthma control improves [2]; and specific HDM-IgE level [2] and local airway inflammation is reduced during a stay at high altitude [3]. Airway specific as well as nonspecific airway reactivity decreases and goes back to baseline values when the patient returns home [4]. Apart from HDM allergens, exposure to pollen is shorter and lower at high altitude, which, in pollen-allergic patients, …