Dr. Felix, an allergist,  has practical experience with natural salt caves from Germany.
Speleotherapy(salt therapy in a cave) is one of the reputable treatment methods for these kinds of diseases, moreover a natural one. The ideal temperature, air humidity, high ionization, rich mineral microclimate and low, almost zero-level concentration of allergens allows patients, allergists in calm state, to significantly reinforce their respiratory tract and whole immune system. In acute states, the microclimate can reduce reaction to allergens and minimize medications needed.