Ailanthus altissima Allergy: Emerging Aeroallergen in the Field of Respiratory Allergies in Romania

Respiratory allergies are among the most prevalent chronic diseases worldwide, and seasonal allergic rhinitis and asthma place a substantial burden on patients and healthcare systems. Pollen from trees, grasses, and weeds contribute to a wide spectrum of clinical manifestations, while globalization, urban landscaping, biological invasions, and climate change are facilitating the spread of new allergenic plants across continents. Ailanthus altissima (tree of heaven) is a fast-growing deciduous tree native to China that has become widely distributed in North America and Europe, including Romania. Although initially introduced as an ornamental and shade tree, its rapid growth, tolerance of pollution and drought, and ability to colonize disturbed urban habitats have increased its relevance as a potential aeroallergen. This narrative clinical review synthesizes evidence from clinical case reports, sensitization studies, molecular allergen characterization, aerobiological monitoring, and Romanian distribution data. To improve clinical and public health applicability, the review includes summary tables comparing Ailanthus with other emerging allergens such as ragweed and Platanus, outlining Romanian ecological and pollen-monitoring evidence, summarizing diagnostic implications for ENT and allergy practice, identifying evidence gaps, and presenting future research priorities. Current evidence supports A. altissima pollen as an emerging but under-recognized respiratory allergen, particularly in urban areas where the tree is established. However, major limitations remain, including the lack of standardized diagnostic extracts, incomplete molecular allergen validation, limited routine pollen monitoring, and absence of Romanian clinical sensitization studies. Greater clinical awareness, species-specific aerobiological surveillance, standardized allergen characterization, and coordinated Romanian sensitization studies are needed to determine the extent to which A. altissima pollen contributes to allergic rhinitis and asthma. Future research should explicitly distinguish species occurrence, airborne pollen exposure, IgE sensitization, and clinically relevant respiratory disease when evaluating the emerging allergenic importance of A. altissima.