Antonella Tosti, MD, is a professor of clinical dermatology at the University of Miami Health System. She is a worldwide recognized expert in hair and nail disorders and has been invited to lecture at major international conferences. She is the author of Dermoscopy of Hair and Scalp Disorders, the first hair and scalp dermoscopy atlas ever published. She is also editor of five textbooks on diagnosis and treatment of hair disorders and three textbooks on nail disorders. Dr. Tosti is the main author of the chapter on nail disorders in several major textbooks and an expert in patch testing for diagnosis of contact allergy. Dr. Tosti is a member of numerous dermatological societies and is the author or co-author of more than 600 scientific publications. Tracey C. Vlahovic, DPM, FFPM, FCPS, is Associate Professor in the Department of Podiatric Medicine, J. Stanley and Pearl Landau Faculty Fellow, Adjunct Professor, Department of Microbiology, Temple University School of Medicine.