Epicutaneous patch testing: current trends and controversial topics

In the 20th century, epicutaneous patch testing has played an integral and central role in the assessment of allergic contact dermatitis and therefore in general dermatologic practice. After recent verification of the safety and accuracy of patch testing by the Food and Drug Administration, domestic distribution of testing materials has resumed for the first time in 5 years. Because of the importance of this procedure, it is timely to review current standards of epicutaneous patch testing with emphasis on proper use and interpretation, clinical applications, trends in allergic contact dermatitis, and selected controversial issues.