Portrait of David Bloom, MD. Dr. Bloom taught at New York Post-Graduate Medical School as an Instructor in Dermatology and Syphilology from 1928 to 1938. He then taught in the Department of Dermatology and Syphilology at the New York University College of Medicine as an Assistant Professor (1948-1950), Associate Professor (1950-1957), and Professor (1957-1961).