Prevalence of sensitization to Quercus ilex pollen and its contribution to Pollen Food Allergy Syndrome in Central Spain

SUMMARY

Background. Quercus ilex is a major contributor to airborne pollen levels in Madrid (central Spain); however, its clinical importance as sensitizer remains unclear. This study aimed to evaluate the prevalence of Q. ilex pollen sensitization, its association with pollen food allergy syndrome (PFAS), and the frequency of sensitization to Que i 1 (PR-10) and Que i 2 (profilin) in a subgroup of Q. ilex-sensitized patients. Methods. We included 60 children and 80 adults with respiratory allergic disease during the spring season. Skin prick tests for spring aeroallergens were performed, and the presence of PFAS was assessed. A group of 41 sera from Q. ilex-sensitized patients were tested by ELISA to determine specific IgE to Que i 1 and Que i 2. Results. 41.7% of children and 53.8% of adults were sensitized to Q. ilex. The most frequent co-sensitizers were P. pratense and O. europaea. PFAS was present in 20% of adult and 15% of children. Q. ilex was the only pollen significantly associated with PFAS in both children and adults (p = 0.0268 and p = 0.0288, respectively). In the group of patients tested by ELISA, Que i 1 was detected in 48.78% and to Que i 2 in 51.22%. Double sensitization was significantly more frequent among PFAS-positive individuals (p = 0.0014). Conclusions. Q. ilex pollen represents a relevant allergen source in central Spain, with sensitization rates near to 50% among patients with spring pollen allergy. Its significant association with PFAS emphasizes its role in allergy disease and supports its inclusion in diagnostic testing.

KEY WORDS