Prevalence of allergic sensitization to Platanus occidentalis among adults with allergic rhinitis: A multicenter study.

Background: In the Americas there are few studies that have evaluated the frequency of allergic sensitization to Platanus occidentalis or sycamore pollen in adult patients with allergic rhinitis (AR).

Objective: To determine the prevalence of allergic sensitization to P. occidentalis and to identify factors associated with its presentation.

Methods: A cross-sectional study was carried out in 3 centers distributed in the northwest, west, and southeast of Mexico. Allergic sensitization to P. occidentalis was determined with a skin prick test. Prevalence and 95% confidence intervals (CI) were estimated.

Results: A total of 404 patients were included, women were 233 (57.7%); the age mean was 33.8 ± 12.9 years. The overall prevalence of sensitization to P. occidentalis was 20.8% (95% CI, 17.1%-25.0%); in the northwestern: 15.9% (95% CI, 9.6%-25.1%); in the western: 21.8% (95% CI, 15.4%-29.9%); and in the southeastern: 22.4% (95% CI, 17.1%-38.8%). Multivariate analysis showed to the following allergens as factors associated with sycamore allergic sensitization: tree pollens (OR, 3.19; P = 0.001), weeds (OR, 2.49; P = 0.004), fungi (OR, 1.96; P = 0.014), and dog or cat epitheliums (OR, 1.88; P = 0.018).

Conclusion: Allergic sensitization to P. occidentalis pollen in AR patients is not an infrequent event; consequently, we recommend doing the challenge test in all patients with this allergen, especially in those regions where the tree is present.