Features that must be part of the description of a primary lesion are listed in Box 11.1. When a patient has several lesions, their distribution must be specified as well as a possibly notable arrangement. It is essential to identify and describe all lesions present and to record their evolution (dynamism). Thus, for example, in chickenpox, primary lesions manifest as vesicles with a cutaneomucosal distribution and no particular configuration. These lesions evolve towards umbilication and crusting, through several asynchronous flares.