Introduction Clinical databases may provide useful information on occupational diseases. Occupational skin diseases are common. Patch testing is performed as part of the diagnostic process for contact dermatitis. There are several large, pooled patch test databases that track results over time. The North American Contact Dermatitis Group is a group of dermatologists in the United States and Canada who use standardized methods for patch testing and reporting and undertake regular analysis of their pooled results.

Objectives Using NACDG data, to examine the diagnoses, common workplace allergens and trends over time for work-related allergens.

Methods Data from North American Contact Dermatitis Group (NACDG) datasets from 2001–2016 were analyzed to determine the frequency of occupationally relevant allergic patch test reactions to a screening tray of allergens and examine trends over time. NACDG members record diagnosis, work-relatedness and industry and occupation using the United States 1990 Census Bureau codes. Descriptive analysis of workers with occupational skin disease was performed using standard statistical tests; logistic regression was used to examine trends over time.

Results Of 38,614 patients tested, 4471 (11.6%) had occupationally-related skin disease; 70.5% of individuals with occupationally-related skin disease had a final diagnosis of allergic contact dermatitis. Fifty one percent were male and the median age was 43. The most common occupationally related agents were rubber accelerators (carba mix, thiuram mix, diphenylguanidine), Bisphenol A epoxy resin, formaldehyde, methylisothiazolinone and metals (nickel sulfate hexahydrate and potassium dichromate). Over the 16 year period there was a significant increase in occupationally relevant responses to carba mix and methylchloroisothiazolinone/methylisothiazolinone and a decrease in 2-mercaptobenzothiazole.

Conclusion Ongoing analysis of pooled patch test databases provides information about the common work-related allergens that can be used to inform prevention activities. Examining trends over time can identify particular allergens for more careful assessment of exposures and help target prevention efforts.