The role of vehicles in diagnostic patch testing. A reappraisal.

The correct selection of vehicles for patch testing is crucial in the evaluation of suspected allergic contact dermatitis. We reviewed the literature by using Grateful Med software for the years 1966-1992, utilizing the subjects "vehicles" and "allergic contact dermatitis" or "patch tests". Vehicles can influence bioavailability of the chemicals and subsequently percutaneous absorption or interaction with allergens. There are methodological problems in interpreting studies, such as sample size, percutaneous absorption and clinical aspects. Our judgement, partially validated by the literature, suggested that improved delivery systems (such as via vehicles) might significantly increase optimization, reliability and reproducibility of patch tests.