ragweed pollen fragments

Ragweed pollen fragments are microscopic particles, typically ranging from 1 to 8 micrometers in diameter, produced by the mechanical grinding or fragmentation of whole ragweed (*Ambrosia*) pollen grains. While intact ragweed pollen grains (approximately 20 micrometers) are generally too large to penetrate beyond the larynx, these smaller fragments can reach the lower respiratory tract. In ragweed-sensitive asthmatic patients, inhalation of these fragments induces significant bronchoconstriction and a decrease in airway conductance, whereas whole pollen grains typically only induce nasal symptoms (hay fever). This suggests that fragmented pollen particles are a primary driver of seasonal fall asthma. These fragments are used as challenge agents in clinical research to study bronchial hyperresponsiveness and the pathophysiology of allergic asthma.

Other names

ground ragweed pollensmall-particle ragweed allergens