191 - Approach to the Adult Rash

A rash is a skin eruption that has a defined morphology and location. The morphology of the rash is usually distinct and related to the pathophysiologic dysfunction of the skin. Most severe rashes begin as exanthems (from the Greek exanthema, which means “breaking out,” and anthos, which means “flowering”). These rashes subsequently take on a particular morphology, characteristic lesions, or distribution. Table 191.1 delineates the most common terms used for skin lesions. Understanding these terms helps one better document progression of disease and facilitates communication with consulting physicians.