A retrospective evaluation of patch testing in patients diagnosed with allergic contact dermatitis

One reason given by clinicians for not using patch testing in patients with dermatitis is that it may not improve the treatment outcome. The main objectives of this retrospective study were to determine the frequency of use of patch testing as an aid to the diagnosis of allergic contact dermatitis (ACD), to determine the ACD-related costs before and after diagnosis of the disease, and to determine the benefit of the diagnosis of ACD, with or without patch testing, to the patient's treatment outcome. This study will also provide definite direction for a prospective outcome study. Medical records of 270 patients with ACD were utilized retrospectively to study the benefit of patch testing. Patch testing was performed on 56 percent of these patients. Patch testing was found to bring about a larger decrease in the disease severity index and percentage disease activity from prediagnosis to postdiagnosis than diagnosis without patch testing. In the group of patients with a prediagnosis disease duration of two months to one year, the postdiagnosis duration was considerably less for those patch tested and treated than those that were treated without patch testing. Patch testing was found to be the most cost-effective in patients with a disease duration of two months to one year.