Swine dust exposure is a model for rapid induction of non-allergic neutrophil inflammation in the nasal mucosa of healthy volunteers, and the symptoms as well as the microcirculation are modified by nasal lavage.

Background: The pathophysiological mechanism of non-allergic rhinitis is not clear and there is a lack of models in healthy volunteers. It has previously been shown that swine dust exposure is an excellent method for inducing inflammatory changes in the lower airways. We have shown earlier that exposure to swine dust increases the histamine sensitivity of the nasal mucosa as measured by rhinostereometry. In this study the aim was to investigate the effects of swine dust exposure on nasal symptoms as well as the microcirculation. Furthermore, the effect on nasal lavage was investigated.

Method: Seventeen subjects were exposed to swine dust during a three-hour period of work in a swine house. Nasal symptoms and the nasal mucosal response to histamine before and after exposure to swine dust were evaluated by laser Doppler flowmetry and nasal lavage.

Results: Exposure to swine dust increased nasal symptoms and levels of neutrophils, IL-8 and albumin. The increase in nasal symptoms and the microcirculation were modified by nasal lavage. CMBC correlated inversely with an increase in albumin (p = 0.018, R = -0.95).

Conclusions: Swine dust exposure is a useful model for inducing nasal inflammation in healthy volunteers. Furthermore, nasal lavage modifies subjective as well as objective parameters, which should be considered when designing studies. Nasal lavage may be useful in the treatment of workers in a swine dust environment.