Hand dermatitis in auto mechanics and machinists.

Background: Auto mechanics and machinists presenting with suspected allergic contact dermatitis (ACD) have traditionally been patch-tested with a standard screening tray and a specialty tray such as the Oil and Cooling Fluid Series. While this has proven useful for patch-testing the machinist, there is a need for the development of a more specific allergen testing tray for the auto mechanic.

Objective: The objective of the study was to compare clinical features and patch-test results of auto mechanics and machinists with hand dermatitis to evaluate differences in allergen profiles.

Methods: We performed a chart review of 33 auto mechanics and 24 machinists referred to our Occupational Contact Dermatitis Clinic from 2002 to 2005 for evaluation of hand dermatitis.

Results: With a panel of 84 allergens, 52 positive reactions were detected in 17 cases of ACD in mechanics. The profiles were different from the cases of ACD diagnosed in 10 of 24 machinists.

Conclusions: Mechanics and machinists differ in the spectrum of occupational exposures. Patch testing with greater numbers of allergens likely identifies a larger proportion of mechanics with occupationally relevant ACD. Further study is needed to determine the most appropriate allergens to include in a clinically useful "mechanic's tray."