Dr. Leonardi is Clinical Professor of Dermatology at St. Louis University Medical School in St. Louis, Missouri, where he also has a private practice. He received his medical degree from the University Of Miami School Of Medicine in Florida and completed an internship in pediatrics and residency in dermatology at the University of Miami/Jackson Memorial Hospital.

Dr. Leonardi is certified by the American Board of Dermatology. He is a fellow of the American Academy of Dermatology and member of the American Dermatological Association. He is a founding member and secretary-treasurer of the International Psoriasis Council. He has served as a member of the medical advisory board of the National Psoriasis Foundation.

Dr. Leonardi has extensive experience using the new biologics in the treatment of psoriasis. He has been an invited speaker at national, regional, and state venues and serves on the advisory boards of several pharmaceutical companies. He has been involved in more than 190 clinical trials and has published more than 200 original articles and abstracts in such journals as the Journal of the American Academy of Dermatology, the British Journal of Dermatology, the Archives of Dermatology, the Journal of the American Medical Association, the New England Journal of Medicine and the Lancet.