Occupational allergy caused by carnation (Dianthus caryophyllus)

Background: Occupational respiratory symptoms caused by decorative flowers are seldom reported in the literature. In our area a large portion of the population works in carnation (Dianthus caryophyllus) winter quarters, and many workers have symptoms of rhinitis and asthma related to exposition. Objective: The purposes of this study were to investigate whether the symptoms induced by carnation were IgE-mediated and to study the possible allergens involved. Methods: A total of 16 subjects employed in indoor carnation cultivation with symptoms during exposition time were studied along with 15 patients with allergic asthma who were not exposed to carnations and 15 healthy carnation workers used as control subjects, Skin prick tests with carnation extract and RASTs were performed. Protein bands were isolated by SDS-PAGE, and afterwards immunoblotting was performed to characterize the extract. Specific nasal provocation and nonspecific bronchial provocation tests were performed for all the asthmatic patients. Diurnal variation in peak expiratory flow was also measured. Results: Skin prick test responses with carnation extract were positive in 15 of the 16 patients and negative in all control subjects. Nasal provocation test responses with carnation extract were positive in 13 of 16 patients. A significant correlation was seen between RAST and nasal provocation results (P < .01). Immunoblotting of sera from 13 patients showed 2 major IgE-binding fractions of 34 and 35 kd in most of the patients, which could constitute the major allergen. Methacholine PD20 showed a variable degree of nonspecific bronchial hyperresponsiveness in all asthmatic subjects. Conclusion: Data demonstrate the involvement of carnation in occupational allergy, mediated by an IgE-dependent mechanism.