Incidence and prevalence rates for occupational contact dermatitis in an Australian suburban area

Occupational contact dermatitis (OCD) regularly causes high levels of worker morbidity; however, this is often not reflected in available statistics. This study aimed to collect and verify OCD reports/ referrals and generate disease estimates for a defined geographical area in Melbourne, Australia. Two methods of data collection were used. In the first method, 30 general practitioners (GPs), 2 dermatologists and 1 dermatology outpatient clinic within a defined area reported each worker with suspected OCD seen as part of routine practice. With the second method, workers living in the area who were referred to a tertiary referral OCD clinic were included in the study. An occupational dermatologist used a gold standard process that included diagnostic patch testing to verify suspected cases. The incidence rate for confirmed cases was 20.5 per 100 000 workers [95 confidence interval (CI): 13a??32.1]. The 1-year-period prevalence rate was 34.5 per 100 000 (95 CI: 24.4a??48.7). The positive predictive value (PPV) was highest for the occupational dermatology clinic referrals [63 (95 CI: 49a??76 )] compared with reports from the dermatologists/dermatology outpatient clinic [55 (95 CI: 36a??74 )] and from GPs [43 (95 CI: 29a??59 )]. This study utilizes reports from GPs and dermatologists to provide OCD disease estimates and validation data for an OCD disease register.