[Ficus benjamina, a perennial inhalation allergen of increasing importance].

12 patients are described with perennial allergic rhinoconjunctivitis or asthma, 3 had additionally urticarial eruptions and one edema of the eyelids. In all of them sensitization to Ficus benjamina was identified by skin prick tests, in 7 cases by the additional presence of specific IgE in vitro, and in 2 it was verified by a conjunctival provocation test. 10 patients were atopic with sensitization to other respiratory allergens such as pollen, house dust mite or animal dander. 2 patients, however, with a massive exposure to Ficus benjamina at home, were non-atopic with monovalent sensitization to this plant. Ficus benjamina is a tropical tree of the genus Ficus which belongs to the Moraceae family. The allergen is located in the plant sap, the so called latex, which after evaporation binds to dust particles on the leaf surface. Upon contact they are emanated from the leaves, thus imitating allergy to house dust components. Since Ficus benjamina is a very popular decorative plant, an increasing number of sensitized individuals is to be expected. The identification of a preventable respiratory allergen is of considerable importance for the patients.