Hypersensitivity to the pollen of Olea europea in the Mediterranean area.

Olive pollen is one of the most important causes of inhalant allergy in the Mediterranean countries (1, 2). We investigated the frequency of hypersensitivity to the pollen of Olea europea in pollen allergic patients in Dalmatia, Croatia (3). A total of 810 patients with pollen allergy, were examined: 469 (58 %) male and 341 (42 %) female, age range from 4 to 53 years. The patients were assessed on the basis of medical history, clinical examination, measurement of pulmonary function (adults and children older than 7 years), intradermal prick test, and immuno-enzyme UniCAP test (UniCAP, Fluoroenzymeimmunoassay; Pharmacia, Upjohn, Sweden) for specific IgE antibodies. We used standard allergen prick tests produced by the Institute of Immunology in Zagreb, Croatia. Our study, like two earlier (4, 5), confi rmed that grasses, especially Parietaria officinalis, are the main pollen allergens. Trees rarely cause allergies in the Croatian part of the Adriatic coast (4). Hypersensitivity to Olea europea occurred in 66 of 810 (8.15 %) assessed patients with pollen allergy. Olea europea and Fraxinus ornus belong to the family of Oleaceae. Both trees are part of the local fl ora. We confi rmed the hypersensitivity to Olea europea allergen and excluded cross-reactivity between these plants by specifi c IgE antibodies measurements. The most prevalent clinical manifestations were rhinitis in 39 (59 %) of 66 patients allergic to Olea europea pollen and bronchial asthma in 20 (30.3 %) patients. It is interesting to note that 51 patients (77 %) lived in towns and the rest in villages; only 3 patients (4 %) lived on the islands. The prevalence of pollen allergies in patients living in the coastal region is recognised in other Mediterranean countries (6). The hypersensitivity to Olea europea allergen in our patients was signifi cantly lower than in other Mediterranean countries (Figure 1); (p<0.01), where varied from 21 % to 31.8 % (7-10). The reason for this difference may be sought in greater industrial pollution (11, 12) and greater area cultivated with olives (13) in other Mediterranean countries.