This article discusses contact urticaria syndrome definition, history, epidemiology, occupational relevance, mechanisms, clinical manifestations, diagnostic tools, agents responsible, and how to prevent and treat the patients affected. Contact urticaria syndrome is often misdiagnosed because it is not well known or recognized by physicians. Commonly the patient recognizes the cause of the clinical symptom, but the cause can be exceptional or new. Triggers include proteins, chemical compounds, agricultural chemicals, metals, plants, foods, and other substances. The objective of this article is to help dermatologists, toxicologists, and immunologists by providing diagnostic tools to avoid the culprit agent and treat the patients.