Israel Medical Association Journal

Background: Allergic rhinitis (AR) is a common illness. Worldwide prevalence varies between 5% and 50% depending on self-reported surveys, test-based studies, geographic location, and age. Despite the clinical relevance of AR in the Israeli population, few studies have characterized the sensitization profiles and key pollen aeroallergen.

Objectives: To describe the most common aeroallergens eliciting a positive skin prick test (SPT) in AR patients across three different main climate zones in Israel.

Methods: We evaluated SPT of aeroallergen sensitization in 1308 AR patients from three topographically and climatically different areas of Israel, describing humidity levels, temperature, and urbanization.

Results: The overall prevalence of positive SPT among patients presenting with AR symptoms was 86%. Indoor aeroallergen sensitization was observed in 76% of patients. Monosensitization was noted in 20% of patients, and polysensitization was noted in 65%. Among the 1308 cases of AR, the top four aeroallergens were mites, olive tree pollen, grass pollen, and cat dander. The top aeroallergen in Israel's central district were mites (62%), olive tree pollen (36%), and grass pollen (30%). In the coastal plains, mites (92%), cat dander (36%), and olive tree pollen (33%) were most prevalent, and in the south mites (77%), olive tree pollen (30%), and grass pollens (26%) were most common.

Conclusions: The top four aeroallergens eliciting a positive SPT were mites, olive tree pollen, grass pollen, and cat dander. Identification of a major aeroallergen can tailor the allergist's SPT panels and specify which aeroallergen should be used for immunotherapy.

The pollen of Ambrosia (ragweed) is one of the major causes of pollen-induced allergy worldwide. This family of plants has apparently evolved in North America but was later spread into Europe and Asia. Flowering of the Ambrosias starts in mid-July and continues throughout the autumn and is a cause of major morbidity to allergic sensitized patients. The invasion of new species of Ambrosia into Israel is still in progress. Plants of Ambrosia artemisiifolia (American short ragweed), Ambrosia trifida (American giant ragweed), Ambrosia confertifolia, Ambrosia grayi and Ambrosia tenuifolia are increasingly found in Israel, mainly in the Hula valley in the eastern Galilee and near the Alexander River in the Sharon plain. From experience it is known that the time it takes to eradicate a new invasive species is limited. Action should be taken immediately or this new invasion will spread and cause a significantly increased burden of morbidity and increased health costs in Israel.