Cypress pollen: an unexpected major sensitizing agent in different regions of Italy

In this multicenter survey, we assessed the impact of sensitization to cypress in atopic patients in Italy and determined whether cypress pollen concentration changed over time.

Allergists were required to collect the results of 100-200 consecutive skin prick tests (SPTs) performed during 2012. Seasonal symptoms were also recorded, as were airborne cypress pollen concentrations (data from the Italian Aerobiology Association) in 1998-2000 and 2010-2012.

We examined 2258 atopic outpatients (56% females; age, 2-84 years) sensitized to at least 1 of the aeroallergens tested (Dermatophagoides species, grass, pellitory, olive, cypress, birch, Alternaria tenuis, and dog and cat dander). We found that 62.9%, 16.1%, and 32.7% of patients living in central, northern, and southern Italy, respectively, were sensitized to cypress (P < .0001). The cypress pollen concentration peak was delayed from February to March in 1998-2000 and 2010-2012 in all 3 regions, with a shift in pollination towards spring. Patients who were monosensitized to cypress reported mainly rhinitis (90.7%-97.6%) and conjunctivitis (38.1%-100%). In polysensitized patients, the prevalence of rhinitis, conjunctivitis, and asthma increased progressively (P < .0001) from southern to northern Italy. The same trend was observed for the prevalence of reported winter symptoms typical of cypress allergy (28%-65%).

Today, cypress pollen is the most frequent sensitizing aeroallergen (assessed by SPT) in several areas of central Italy. Variations in the timing of the cypress pollination period may have favored this increased sensitization. Rhinitis and conjunctivitis are the predominant symptoms. The clinical impact of this allergy was poor in southern Italy and increased in central areas before reaching its peak in northern regions.