Intern in medicine University Iowa Hospitals, Iowa City, 1967-1968. Resident in dermatology skin and cancer unit New York University Medical Center, 1970-1973. National Institutes of Health training fellow, guest investigator Rockefeller University, 1971-1973, Richard Joshua Reynolds scholar in clinical medicine, assistant professor, associate physician, 1976-1977.
Assistant professor dermatology Columbia University College Physicians and Surgeons, 1973-1976. Assistant attending dermatologist Presbyterian Hospital, New York City, 1973-1976. Professor dermatology, chairman department Case Western Reserve University Medical School, 1977-1993, associate dean, 1990-1993.
Director dermatology service University Hospitals, 1977-1993, senior vice president medical program planning, 1977-1989, chief staff, senior vice president medical affairs, 1990-1993. Director dermatology service Cleveland Veterans Administration Hospital, 1977-1989. Member general medicine A study section, National Institutes of Health, 1980-1984, chairman, 1982-1984.
Advisory council National Institute Arthritis, Musculoskeletal and Skin Diseases, National Institutes of Health, 1988-1992. Carl Truman Nelson professor dermatology, chairman Department College Physicians and Surgeons, Columbia University, since 1994. Director dermatology service New York Presbyterian Hospital Columbia Division, since 1994, president medical board.
Author: (with L.C. Harber) Photosensitivity Diseases: Principles of Diagnosis and Treatment, 1981, 2d. Edition, 1989, (with Hazen and Lynch) Clinical Pharmacology of Skin Disease, 1984, (with T. Krieg and Y. Miyachi) Therapy of Skin Disease, 2008. Member editorial board Journal American Academy Dermatology, 1979-1985, Physicians Drug Alert, since 1982, Today's Therapeutic Trends, 1983-2004, Photodermatology, 1983-1988.
Associate editor Journal Investigative Dermatological, 1987-1997.
Served as officer Medical Corps United States Air Force, 1968-1970. Member Association American Physicians, American Society Clinical Investigation, American Society Pharmacology and Experimental Therapeutics, American Federation Clinical Research, American Society Photobiology, American Academy Dermatology (honorary), American Dermatological Association, Society Investigative Dermatology (board directors 1985-1989, secretary-treasurer since 1989, president 2003), Pasteur Club (Cleveland), Medical Strollers, Skin Pharmacology Society (secretary 1985-1987, president 1987-1989), Dermatology Foundation (secretary-treasurer 1984, chairman board 1987-1988), Bicontinental Association Education and Research in Dermatology (founding member), German Dermatological Society (honorary), American University Beirut (board trustees, since 1996, chair health science committee, since 2005), Austrian Dermatological Society (honorary), Commanderie De Bordeaux, Confrérie des Chevaliers du Tastevin, Expert Panel Research Institute for Fragrance Materials, 1996 (chair, 2002-2005), American Board Dermatology (board directors 1997-2005, president 2005).