Background: A specialist patch test clinic was set up in April 1997 at the Department of Dermatology, South Infirmary-Victoria Hospital, Cork, Ireland. The number of batteries available was expanded from six to 21 and the routine testing of patients to their own products was introduced, as was prick testing for latex hypersensitivity.
Objectives: To assess the impact of introducing this clinic on the detection of allergic contact dermatitis.
Methods: Patch test results for the first full year of operation of the clinic (1998) were compared with those in the year prior to setting it up (1996).
Results: Although the number of patients tested rose after the introduction of the new clinic, the difference was not significant as the number of new dermatology general referrals had also risen. Thirty-one of the 91 patients tested in 1996 had positive patch tests compared with 84 of 158 tested in 1998 (P = 0.0036). Eighteen allergens were detected in 1996 and 53 in 1998. Two patients were positive to their own products in 1996, compared with 12 in 1998 (P = 0.04). The commercial batteries were negative in four of these cases. Three cases of latex hypersensitivity were detected in 1998.
Conclusions: The introduction of a specialist patch test clinic resulted in an increase in detected cases of allergic contact dermatitis. The larger range of batteries available and the more widespread testing of patients' own products were the principal factors involved.