Role of vascular reflex in nasal mucosal swelling in nasal allergy

Objective: In patients with nasal allergy, antigen challenge on the unilate ral nasal mucosa results in nasal secretion not only in the ipsilateral but also in the contralateral nasal cavities that can be inhibited almost comp letely by premedication with atropine sulfate. The present study was perfor med to elucidate if centrally mediated vascular reflex induced by antigen c hallenge plays a role in nasal mucosal swelling in subjects with nasal alle rgy. Methods: Variations of mucosal swelling and mucosal blood flow in the ipsilateral and the contralateral nasal cavities after unilateral antigen c hallenge were evaluated by acoustic rhinometry and laser Doppler flowmetry in 20 patients with perennial nasal allergy. Results: Unitateral antigen ch allenge caused ipsilateral and contralateral nasal mucosal swelling in 17 a nd 13 patients, respectively. Incidence of contralateral nasal mucosal swel ling after unilateral antigen challenge was significantly higher compared w ith that after control disc challenge (P <.001). In 10 patients in whom uni lateral antigen challenge caused bilateral nasal mucosal swelling, signific ant swelling of the nasal mucosa lasted for more than 30 minutes in the ips ilateral nasal cavity after antigen challenge compared with only 15 minutes in the contralateral nasal cavity, Peak values of contralateral mucosal sw elling were 45.3% of those of ipsilateral nasal mucosa, Conclusions: Centra lly mediated vascular reflex is partially involved in the onset of nasal mu cosal swelling observed after antigen challenge in subjects with nasal alle rgy. However, nasal mucosal swelling that persists and proceeds even 20 min utes after antigen challenge is caused by the direct effects of chemical me diators on the nasal vasculature.