Even those clinicians who feel themselves far from aesthetic dermatology now recognise that BoNT-A is an extraordinary tool in their therapeutic armamentarium for treating complex disorders such as focal idiopathic hyperhidrosis. This has opened a therapeutic scenario for a group of patients very difficult to treat previously. Since the introduction of BoNT-A in the dermatological therapeutic armamentarium, in 1990, things have changed to the point that any dermatologist should now have knowledge of BoNT-A basics, and the practicalities of BoNT-A vial reconstitution and injection. Moreover, in the last years, a widespread availability of multiple different commercially available forms of BoNT-A has been for sale, thus the clinicians must now really know and consider the advantages and disadvantages of the different available products. These would include dosing/duration, immunogenicity, and spread of effect. What has not changed over the years is the safety profile of BoNT-A. The knowledge regarding its side effects and complications have greatly increased, confirming that, despite the attempts of some individuals to assert otherwise, BoNT-A remains one of the safest forms of treatment available to us as physicians. This edited collection provides a comprehensive practical guide on the use of botulinum toxin in several dermatological disorders, including focal idiopathic, axillary, palmar and plantar, craniofacial or segmental hyperhidrosis, chrono-aging, hidradenitis, and gives some suggestion on the use of BoNT-A for the treatment of several orphan skin diseases, not responding to conventional treatments like benign Hailey-Hiley disease, lichen simplex, osmidrosis. Using clear explanations, simple line drawings, diagrams and clinical pictures, it provides suggestions to improve practical knowledge on the use of BTX-A in dermatology. Hot topics include practical information for clinicians regarding the correct counselling of the patients to be treated; methods and ready to use tests to select patients to be treated; the optimal dosage and dilution according to the site of injection and the indication of use; the relevant injection sites for each condition; the correct technique of injection in the different areas of body surface; comparative dosage tables for the various formulations of toxin used; how to manage and prevent side effects related to the use of BoNT-A; common pitfalls and how to optimize outcomes; timing for the follow-up of treated patients. The authors hope that this book may be a starting point for the use of a drug that is still growing, and a useful tool for those clinicians who want to improve their knowledge about the use of BoNT-A in dermatology.