There is no definitive cure for AA (Alopecia areata), and several commonly used treatments require proof of effectiveness, efficiency, and security. This manual provides the reader with the minimum and necessary knowledge about Evidence-Based Medicine and the dermatological disease known as AA. It also presents a broad systematic review of the medical literature on treatments (published randomized clinical trials) and analyzes each treatment's effectiveness. Although not intended to replace specialized books, reading this manual can help decide the best (evidence-based) treatment of AA (and its variants Alopecia Totalis - AT and Alopecia Universalis - AU) for Dermatology training and various specialties trained doctors.