No Concentration Decrease of House Dust Mite Allergens With Rising Altitude in Alpine Regions

Area of Science:

• Environmental Science
• Allergen Research
• Climate Change Impact

Background:

• Historically, altitudes above 1,500m showed reduced house dust mite (HDM) and allergen levels.
• This observation formed the basis for allergen avoidance therapies in HDM allergy and asthma.
• Modern construction and global warming may alter HDM habitats, necessitating a re-evaluation.

Purpose of the Study:

• To re-examine the traditional understanding of decreasing HDM allergen concentrations with increasing altitude.
• To investigate HDM allergen levels in alpine regions of Germany and Austria under current environmental conditions.

Main Methods:

• Analyzed 122 dust samples from various accommodations (hotels, private homes, mountain huts) across altitudes (400-2,600m).
• Measured HDM allergen concentrations, humidity, temperature, fine dust, flooring types, building age, and cleaning frequency.

Main Results:

• HDM allergen concentrations showed no significant correlation with increasing altitude or relative humidity.
• Significant correlations were found between specific indoor flooring types and HDM allergen concentrations.

Conclusions:

• Clinically relevant HDM allergen concentrations persist in high-altitude alpine regions, contrary to prior beliefs.
• Improvements in asthma symptoms at high altitudes may not be solely due to reduced HDM allergen exposure.
• Alternative mechanisms likely contribute to the beneficial effects observed in asthmatic patients at high altitudes.