Contact Dermatitis in California Nursery Workers: Part I. Surveillance of Skin Disease

From use of electronic summaries of workers' compensation cases and employment records, nursery workers have previously been identified as a group at high risk for occupational skin disease. This prior research has not identified either the specific skin conditions involved or the plants and agricultural chemicals responsible. This report describes 441 suspected cases of skin disease among nursery workers collected by the California Pesticide Illness Surveillance Program (PISP) between 1989 and 1992. Reports for these cases were reviewed in detail and coded for analysis, including identification of specific plants and chemicals involved. The skin condition(s) identified from the reports were coded using the 9 th Revision of the International Classification of Diseases (ICD) codes. The reported cases included 180 (40.8%) with sufficient relation to a pesticide exposure to merit PISP investigation. Information on the remaining 261 cases was coded solely from the initial workers' compensation report. The 261 non-pesticide cases included 122 cases (46.7%) of contact dermatitis due to plants (ICD 692.6), 79 (30.3%) cases of dermatitis due to non-specified causes (ICD 692.9), 13 cases (5.0%) of urticaria (ICD 708.9), 11 cases (4.2%) of tinea (ICD 110.0), 8 cases (3.1%) of finger/thumb cellulitis and 7 cases due to fertilizers and other non-pesticidal nursery chemicals. Two cases of urticaria were also coded as having contact dermatitis due to plants and two cases of finger/thumb cellulitis were also coded as cases of tinea. For the 122 cases of plant contact dermatitis, a particular species of ornamental plant was associated with the reported case in 44 (33.1%). The most frequently reported individual plant species included primrose, poinsettia, carnation, tulips, and daffodils. Of the 180 suspected pesticide-illnesses, 91(50.6%) were classified in the PISP database as at least possibly related to pesticide exposure (termed pesticide-related cases), and the remainder were classified as unrelated or unlikely to be related. Mixtures of active ingredients accounted for 38 (41.8%) of the pesticide-related cases and individual compounds associated with 5 or more cases included benomyl, abamectin, iprodione, thiophanate methyl, fluvalinate, chlorothalonil, insecticidal soap, mancozeb, dienochlor, and acephate. Of the 91 cases, 59 (64.8%) were diagnosed as contact dermatitis due to chemicals (ICD 692.4), 25 (27.5%) as contact dermatitis due to unspecified cause (692.9), 5 (5.5%) as burns (ICD 949.0), and 2 (2.2%) as urticaria (ICD 708.9). Three cases in the surveillance study included information about provocation testing, all working for a single northern California conifer nursery. One case from this group, previously published, had a marked immediate allergic reaction to chlorothalonil, but negative reactions to other pesticides. The two coworkers had negative reactions to all materials tested. No provocation testing for either plants or chemicals was apparently carried out on any of the other cases reviewed in the study. Detailed review of workers compensation and pesticide illness investigation records provided some previously unavailable details regarding specific skin conditions, agricultural chemicals, and plants associated with skin disease in the nursery industry. The limitations of the compensation data were indicated by the high percentage cases for which no specific causal agent could be identified. From the available information, provocation testing was carried out in less than 1% of the cases reported.