Background:
Patch testing is commonly used in dermatologic practice for the diagnosis of contact dermatitis.
Objective:
The objective of this study was to describe the patient population of an occupational contact dermatitis clinic and compare the results of patch testing in this setting with the pooled results from other patch test clinics.
Methods:
Patch testing was performed using standardized methodology in 14 clinics in North America.
Results:
The prevalence of positive patch test responses is influenced by the age and sex distribution of the population. When the Toronto occupational contact dermatitis clinic results were compared with those of the other centers in North America, there was an increased prevalence of positive responses to colophony, paraphenylenediamine, and nickel in the Toronto group.
Conclusions:
Although the patient mix is different in an occupationally oriented patch test clinic, when appropriate corrections are made for age and sex differences, the results of patch testing are generally similar to pooled results from a number of dermatology clinics. The differences in results do not reflect a strong occupational difference but may reflect a difference in exposure to various materials.
