Each medical specialty has an exam that is taken to show competence in that specialty. In Dermatology, basic science is covered, as well as pathology, surgery, medications, and cosmetic aspects. After graduation as an MD from UT Health Center in San Antonio, I spent three years in a Pediatric Residency, then one year on the Pediatric ER faculty, then three years in Dermatology.  I was Board Certified in Pediatrics in 1980 and Dermatology in 1983.