Allergic rhinitis and asthma in southern Croatia: impact of sensitization to Ambrosia elatior.

Aim: To identify pollen types in southern Croatia and investigate the impact of sensitization to Ambrosia elatior (A. elatior) on symptoms and treatment of patients with seasonal allergic rhinitis and/or asthma.

Methods: The study recruited 120 patients from Split-Dalmatian County with seasonal rhinitis and asthma symptoms and positive skin prick test to one or more common inhaled allergens. Patients with positive skin prick test and increased specific IgE to A. elatior (n=56) were included in the follow-up study during the A. elatior pollen season. Rhinitis and asthma symptoms were scored and drug treatment recorded using standardized questionnaires. Also, forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), and eosinophil count in peripheral blood were measured. Type and pollen concentration of A. elatior in the air over the nine-week pollen season were determined on the glass slides using the gravimetric method. The results were expressed as the proportion of A. elatior pollen in the total pollen.

Results: Fifty-six of 120 patients (46.7%) were sensitized to A. elatior. Its proportion in total pollen peaked to 12% in the first week of September. Forty-one patients who completed the follow-up study showed a significantly higher score of symptoms during this peak period than in the beginning of the pollen season for seasonal allergic rhinitis (median +/-interquartile range, 50+/-11 vs 7+/-4; P<.001) and for seasonal allergic asthma (12+/-2 vs 0+/-0; P<.001).

Conclusion: A. elatior is an important cause of seasonal allergic rhinitis and asthma and must be included in the routine diagnostic procedures in southern Croatia.