Designed as an essential resource for clinicians, researchers, and students, the book provides a thorough understanding of both systemic and topical therapies in dermatology. Besides, it features detailed discussions on retinoids, biological immunomodulators and immunosuppressive agents--core components of modern dermatologic treatment. Enhanced with numerous flow diagrams and tables the book effectively illustrates key concepts and therapeutic pathways, offering readers a clear and structured perspective on clinical decision-making in dermatology. This is volume 1 of the set of three volumes.