Dr. Simpson practices medical dermatology with special interests in chronic inflammatory skin diseases and skin cancer. He is actively involved in clinical research and is currently funded by the National Institutes of Health and industry partners to study new approaches to chronic skin disease treatment and prevention.

Dr. Simpson's collaborations are global in scope and has been invited to present his research and approach to patient care at international conferences in Europe, North and South America, and Asia. He has published over 140 scientific articles in several high-impact peer-reviewed journals including the New England Journal of Medicine and The Lancet. 

As part of his commitment to lessen the burden of atopic dermatitis (eczema) worldwide, Dr. Simpson is dedicated to identifying and improving quality of care for patients with atopic dermatitis. He is the director of the Frances J. Storrs and Jon M. Hanifin CLEAR Eczema Center at OHSU. Furthermore, he supports patient advocacy by serving as the Co-Chair of the Scientific Advisory Committee for the National Eczema Association.  He also serves on the Executive Committee of the Harmonizing Outcome Measures in Eczema (HOME) - a volunteer group of patients, providers, and other stakeholders whose mission is to improve the quality of eczema research to better suit the needs of patients and policy-makers.

Outside of work, Dr. Simpson enjoys spending time with his wife and children, playing squash, camping, hiking, fishing, and biking.