Background: Over the last 30 years there has been increasing recognition of the clinical entity contact urticaria (CU) and the related diagnosis, protein contact dermatitis. However, there are relatively few reports of the occupational relevance of this condition.
Objectives: To describe relevant characteristics of patients diagnosed with occupational CU (OCU) in a tertiary level specialist occupational dermatology clinic in Australia.
Methods: We performed a retrospective analysis of all patients diagnosed with OCU at an occupational dermatology clinic in Melbourne between 1 January 1993 and 31 December 2004. We identified 151 cases of CU diagnosed over the 12-year period.
Results: OCU was diagnosed in 8.3% (143 of 1720) of the total number of patients with occupational skin disease. Natural rubber latex accounted for the majority of all cases of OCU. Other common causes were foodstuffs and ammonium persulphate utilized as hairdressing bleach. The most commonly affected sites were the hands, followed by the arms and face. The most frequently affected occupations were healthcare workers, food handlers and hairdressers. All cases of CU in patients with hand symptoms were assessed to be work related. Atopy was a significant risk factor for both latex-related and nonlatex-related OCU.
Conclusions: Radioallergosorbent tests and skin prick testing, including to patients' own food samples, should be part of the routine assessment of patients in high-risk occupations for OCU, particularly if the hands are affected, there is a history of atopy and there is exposure to urticants. We emphasize the importance of both determining the role of occupation in the causation of CU and recognizing all contributory factors in complex cases of occupational contact dermatitis of the hands.