Influence of aeroallergens on bronchial reactivity in children sensitized to grass pollens

Nine children, sensitized to grass pollens, with seasonal rhinitis and mild asthma underwent bronchial challenge with carbachol and EIA test repeatedly either during a pre-seasonal or in seasonal period. We failed to find any significant difference between pre-seasonal and seasonal values in both tests. We believe that atmospheric conditions are an important determinant of our results. It is our hypothesis that a threshold concentration in atmospheric pollen may exist which must be reached before an allergic reaction is evident.