Shawn Cowper, MD

Shawn E. Cowper, MD, specializes in using microscopy to diagnose skin diseases and conditions, as well as hair loss, or alopecia. His expertise on the latter runs beyond skin deep. Dr. Cowper is co-author of a textbook on the topic, called An Atlas of Hair Pathology with Clinical Corrections, and regularly fields alopecia-related questions from Yale Medicine dermatologists and physicians around the world.

Dr. Cowper’s interest in dermatopathology (a pathology subspecialty that focuses on skin biopsies only) developed after he spent time as a family doctor treating dermatologic conditions. Dermatopathologists have been trained to recognize structural changes that occur on a cellular level in skin diseases. Dr. Cowper says he chose the subspecialty because it joined two interests: a patient’s symptoms and the science-intensive nature of pathology. “In dermatopathology, it’s a team sport between the dermatologists and family physicians who provide the patient history and clinical impressions, and the dermatopathologists who correlate this with the microscope findings to reach a final diagnosis,” he says.

During his time as a fellow at the University of California San Francisco, Dr. Cowper’s passion for combining patient stories and scientific evidence resulted in the discovery of a new disorder. Dr. Cowper, and a team of physicians and researchers, described a mysterious disease they called “nephrogenic systemic fibrosis” (NSF). The disease, which developed only in people with kidney disease, was eventually found to be caused by gadolinium-based contrast agents, which are used in magnetic resonance imaging (MRI) procedures. “While the number of new cases of NSF grew steadily in the early 2000s, since about 2010, the number of new cases has been reduced to essentially zero,” Dr. Cowper says. “Before the cause was determined, people were dying of this disorder. It freezes people’s limbs, so they cannot flex their knees, hands, or feet.” Dr. Cowper presented evidence to the Food and Drug Administration (FDA) that led to new guidance for gadolinium use so that people at high risk for NSF could be recognized before receiving this potentially disabling—or deadly—agent.

At Yale School of Medicine, Dr. Cowper is an associate professor of dermatology and pathology. Besides NSF, his research interests include adnexal tumors, and the pathological findings in hair loss. Dr. Cowper routinely teaches peers and resident physicians in dermatology and pathology how to best interpret hair biopsy specimens.