This study analyzes the influence of the IgE response to certain olive pollen allergens in the modulation of the different clinical phenotypes of allergic disease and their relationship with the level of exposure to pollen and genetic factors. Patients from high-exposure areas had a complex IgE antibody response to allergens of Olea euroapea, which included 3 or more allergens in 75% of cases. The majority allergens were Ole e 1, Ole e 2 (profilin), Ole e 7 (lipid transporting protein), Ole e 9 (glucanase), and Ole e 10. The existence of the antigen HLA-DR2 (15) led to a higher risk of sensitization to Ole e 10 and a greater trend towards the development of severe asthma, which increased in the presence of an anti-profilin IgE. Thirty percent of patients suffering from pollinosis simultaneously presented allergy to vegetable foods. Anti-Ole e 7 IgE was significantly associated with fruit anaphylaxis and anti-profilin IgE was detected in 90% of patients with oral syndrome. Finally, we analyzed the role of glucanase and Ole e 10 as causes of the pollen-latex-fruit syndrome.