Asthma caused by Ficus benjamina latex: evidence of cross-reactivity with fig fruit and papain Marı ´a Luz Dı ´ez-Go ´mez, MD; Santiago Quirce, MD, PhD; Elena Aragoneses, MD; and Manuela Cuevas*, MD, PhD Background: Ficus benjamina or weeping fig is a plant used increasingly for indoor decoration that can cause allergic rhinitis and asthma. Objective: We report a clinical and immunologic study in a patient with peren- nial asthma caused by F. benjamina latex in whom several episodes of angioedema of the oropharyngeal tract and tongue followed ingestion of figs and kiwi. Methods: Hypersensitivity to latex from F. benjamina and from Hevea brasil- iensis, fig fruit, kiwi, papain, and bromelain was investigated by means of skin prick test, specific IgE determination by CAP, histamine release test, and bronchial provocation test to F. benjamina latex. CAP-inhibition assays were carried out to study possible cross-reactivity among these antigens. Results: Hypersensitivity to F. benjamina latex, fig, kiwi, and proteases was demonstrated by means of skin prick test, determination of specific IgE and histamine release test. Bronchial provocation test with F. benjamina latex resulted in a dual asthmatic reaction, confirming the etiologic role of this plant. A rise of eosinophil cationic protein in patient’s serum was observed 21 hours after bronchial challenge, suggesting activation of eosinophils. Inhibition assays showed that F. benjamina latex as liquid-phase inhibited up to 95% the CAP to fig and up to 57% the CAP to papain. Neither sensitization nor cross-allergenicity with H. brasiliensis latex was found. Conclusions: Hypersensitivity to F. benjamina latex may cause IgE-mediated respiratory allergy. The association with allergy to fig and papain is likely due to the existence of cross-reactive allergen structures. Ann Allergy Asthma Immunol 1998;80:24–30. INTRODUCTION Ficus benjamina or weeping fig (Fig 1) is a non-flowering green plant from the family Moraceae frequently used in the decoration of homes, office premises and public buildings. It grows into a very leafy small tree, with a mean height of 1.5 to 2 meters. Hypersensitivity to this plant was first described by Axelsson et al as an occupational disease in 1985. 1 They reported two atopic plant keepers working for a company specialized in the leasing of green plants in whom rhinoconjunctivitis and asthma devel- oped on exposure to F. benjamina. Specific IgE against leaf and twig ex- tracts from this plant was demonstrated by skin tests and RASTs. In a subse- quent study 2 in four plant-leasing firms employing 60 plant keepers, it was found that 26.6% of the workers had positive skin-prick tests and RAST against F. benjamina latex. All sensi- tized subjects suffered from rhinitis or conjunctivitis and six had asthma. The fig is the fruit of the fig tree (Ficus carica) which also belongs to the family Moraceae. A single case of anaphylactic reaction after eating a fresh fig has been recently described in a nonatopic patient. In this patient, se- rum specific IgE antibodies against both fig and F. benjamina were found. A partial inhibition of CAP to F. ben- jamina with fig suggested the exis- tence of cross-reactivity between both species of Ficus. 3 We describe a clinical and immuno- logic study of an atopic patient suffer- ing from perennial rhinoconjunctivitis and asthma. Sensitization to F. ben- jamina latex was demonstrated by in vivo and in vitro tests. The patient had also had several episodes of angio- edema after ingestion of figs and kiwi (Actinidia chinensis). Cross-reactivity between F. benjamina latex, fig, pa- pain, and the latex of the rubber tree Hevea brasiliensis was investigated. CASE REPORT A 36 year-old woman, who was a smoker of ten cigarettes/day, had suf- fered from allergic rhinoconjunctivitis due to Olea europaea (Mediterraneum olive) pollen during more than 10 years as well as cough, dyspnea, and wheezing during the last pollen season (from May to June). She took antihis- tamines and disodium cromoglycate for symptom relief, and she received immunotherapy with O. europaea pol- len during 2 years but it had been stopped due to large local reactions. Since 1993 she had suffered from perennial episodes of shortness of breath, coughing, wheezing, and rhino- conjunctivitis. Antiasthma therapy with nedocromil, salmeterol, and theo- phylline daily as well as albuterol as needed had been prescribed. At a rou- tine follow-up allergy evaluation in January, 1996, she reported that rhino- conjunctivitis as well as dyspnea and wheezing developed immediately when she was cleaning and taking care From the Department of Allergy and *De- partment of Immunology, Hospital Ramo ´ n y Ca- jal. Madrid, Spain. Received for publication December 6, 1996. Accepted for publication in revised form May 20, 1997. 24 ANNALS OF ALLERGY, ASTHMA, & IMMUNOLOGY