Skin disease is common in the United States and accounts for a considerable fraction of all outpatient visits. Dermatologists care for more skin disease visits than any other single specialty, while still accounting for a minority of visits overall. The data presented in this introduction, from 1997, do not show a drastic drop in the number of visits to dermatologists as might be feared to occur with the growth in managed care. These visits for skin disease represent a considerable disease burden in the United States. Skin disease is not simply a cosmetic problem. As the data on psoriasis show, skin disease has a tremendous impact on HRQL. The magnitude of this impact on the individual patient is comparable to the impact of other medical disorders.