The Dictionary of Contact Allergens is a helpful guide for the reader to familiarize with the structures of chemicals implicated in contact dermatitis. Each molecule is described with its principal name for classification. The most important synonyms, the Chemical Abstract Service (CAS) Registry Number that characterizes the substance and its chemical structure and relevant literature references are also listed. Further, the reader will find a unique chapter on Patch Testing with the patients own products. This guide is a must-have for each physician involved with the diagnosis and treatment of patients with contact dermatitis and allergic skin disease.