title: Hyposensitization to poison ivy after working in a cashew nut shell oil processing factory.
abstract: 19 adults were patch tested to urushiol, the allergen in poison ivy/oak, to determine their sensitivity to this allergen after working in a cashew nut shell oil (CNSO) processing plant. The cashew nut tree and poison ivy/oak are in the same botanical family. Anacardiaceae, and they share similar chemicals which cause allergic contact dermatitis. 13 of the 19 workers had a preemployment history of poison ivy sensitivity, with 10 developing CNSO dermatitis. After working in this factory for several months, 9 of the 13 noticed a decreased sensitivity or no sensitivity to poison ivy/oak. When tested to urushiol extract, only 3 reacted positively, 2 minimally. These results imply that hyposensitization to poison ivy/oak occurred in these employees after development of hardening to cashew nut shell oil.
authors.affiliation: Division of Dermatology, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033.
authors.forename: R F
authors.initials: RF
authors.lastname: Reginella
authors.forename: J C
authors.initials: JC
authors.lastname: Fairfield
authors.forename: J G
authors.initials: JG
authors.lastname: Marks
mesh_terms: D002396:Catechols / Q000009:adverse effects* / Q000276:immunology; D011040:Dermatitis, Toxicodendron / Q000175:diagnosis / Q000209:etiology / Q000276:immunology*; D003888:Desensitization, Immunologic; D004781:Environmental Exposure; D005525:Food-Processing Industry; D006801:Humans; D009754:Nuts / Q000276:immunology*; D010328:Patch Tests; D010938:Plant Oils
chemical_list: D002396:Catechols; D010938:Plant Oils; C003747:urushiol