title: Immediate allergic and nonallergic reactions to Christmas and Easter cacti.
abstract: BACKGROUND
  Occupational exposure to Christmas cacti has been reported as a cause of type I allergy. Therefore, the prevalence of immediate-type mucosal and skin reactions related to cactus exposure was studied in 103 employees in a cactus nursery.
  
  
  METHODS
  The study was based on a questionnaire followed by clinical examination, skin prick tests (SPT) with standard inhalant allergens and cacti, and a histamine-release test (HRT/Refix) using fresh cactus extracts as elicitor.
  
  
  RESULTS
  The questionnaire was answered by 84 (82%) of the nursery employees, and 63 (61%) were interviewed and skin prick tested; 58 of these were tested with HRT/Refix. Furthermore, 22 healthy controls were included and tested in vivo and in vitro. Cactus-related contact urticaria and/or rhinoconjunctivitis were reported by 37% of the cactus workers. Based on a combination of positive history, positive SPT, and positive HRT/ Refix to cactus, 8% of the cactus workers were allergic to cacti. No noncactus workers or controls were allergic to cacti by these criteria. Testing with fresh cactus material elicited positive SPT and negative HRT/Refix in 27 nursery workers and controls, of whom 12 had immediate-type skin and mucosal symptoms.
  
  
  CONCLUSIONS
  Christmas and Easter cacti seemed to be able to induce contact urticaria and rhinoconjunctivitis on both an immunologic and a nonimmunologic basis. Personal atopy was associated with positive reactions to cacti.
authors.affiliation: Department of Dermatology, Odense University Hospital, Denmark.
authors.forename: F
authors.initials: F
authors.lastname: Andersen
authors.forename: C
authors.initials: C
authors.lastname: Bindslev-Jensen
authors.forename: P
authors.initials: P
authors.lastname: Stahl Skov
authors.forename: E
authors.initials: E
authors.lastname: Paulsen
authors.forename: K E
authors.initials: KE
authors.lastname: Andersen
mesh_terms: D000485:Allergens; D003233:Conjunctivitis, Allergic / Q000453:epidemiology / Q000209:etiology; D006636:Histamine Release; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000453:epidemiology* / Q000209:etiology; D016273:Occupational Exposure; D010936:Plant Extracts / Q000009:adverse effects*; D010944:Plants / Q000009:adverse effects*; D015995:Prevalence; D012220:Rhinitis / Q000453:epidemiology / Q000209:etiology; D012882:Skin Tests; D011795:Surveys and Questionnaires; D014581:Urticaria / Q000453:epidemiology / Q000209:etiology
chemical_list: D000485:Allergens; D010936:Plant Extracts