The fourth edition of this important book, which includes additional color illustrations, has been extensively revised, updated, and expanded to reflect the most recent developments. These include advances in patch testing methodology, in particular the new chambers that are appearing on the market, revision of the baseline series of patch tests to reflect the latest evidence-based work, and additional testing procedures. Other additions include sections on key allergens and concentrations, with the result is a superb guide to the current management of positive and negative patch test and prick test reactions that will be invaluable for all practicing dermatologists, from the beginner to the well-trained expert.

The fourth edition continues the tradition of partnering with the ICDRG (International Contact Dermatitis Research Group). The ICDRG was formed in 1966 to promote the understanding of contact dermatitis.