Here is a helpful guide, A-to-Z guide on the structures of chemicals implicated in contact dermatitis. It describes each molecule along with its principal name for classification. The dictionary also lists the most important synonyms, the Chemical Abstract Service (CAS) Registry Number that characterizes the substance and its chemical structure, and relevant literature references. In addition, the reader will find a unique chapter on Patch Testing with the patient’s 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.