This document provides an overview of dermatology for medical students and junior doctors. It discusses key topics including: - Skin diseases affect 30% of the population at any given time. - The functions of the skin include protecting from microorganisms, regulating temperature and fluid loss, and synthesizing vitamin D. - Psoriasis is a common skin condition affecting 1-2% of the population. It involves abnormal differentiation and hyperproliferation of keratinocytes. - Melanoma incidence is around 9,000 people per year in the UK. It is a malignant proliferation of melanocytes. - Around 9,000 of the 36,000 possible medical diagnoses are dermat