Exposure to Cypress Pollens and Subsequent Symptoms: A Panel Study

Abstract

Objective: The objective of this panel study was to document the relationship between exposure to cypress pollen and allergic symptoms.

Methods: The study group included 47 patients with allergy to cypress pollen who completed a daily diary and a weekly evaluation of quality of life (QoL) during the cypress pollen season. Different patients were included in three consecutive pollen seasons: 2014-2015, 2015-2016, and 2016-2017. Daily cypress pollen counts were obtained from the National Aerobiological Network. Air pollution and meteorological data were recorded on a daily basis. The pollen-symptoms relationship was quantified by calculating odds ratios for an increase of 1 log of grains of pollen/m3, taking into account potential confounding factors. The QoL score was expressed with a beta coefficient that increased with 1 grain of pollen/m3.

Results: There was a marked increase in rhinitis and ocular symptoms during the pollen season, with a plateau effect at high levels of exposure, but no relationship with bronchial symptoms. The QoL score had a linear and significant relationship with the cypress pollen count. We did not detect any threshold level.

Conclusion: This panel study demonstrated a significant association between exposure to cypress pollens and allergic symptoms, with a plateau effect for high exposures.

Keywords: Allergy; Conjunctivitis; Cypress; Environment; Pollen; Rhinitis.