This skin disease section of NHANES, as currently planned for 2001, includes an imaging component with four standardized photographs to be obtained from each survey participant (SP). The selection of the regions to be photographed is designed to maximize the information obtained, while preserving patient privacy and is based on the known distribution of clinical findings of the three conditions, as well as NHANES logistical limitations. This validation study is a cooperative effort between the NIAMS extramural programs, the NCI intramural program, and the National Center for Health Statistics.