Vasculitic skin rash is a rare but known manifestation of azathioprine hypersensitivity reactions, with several published case reports. In this report, we describe the case of a 63-year-old man on azathioprine for autoimmune hepatitis, who developed a delayed systemic hypersensitivity reaction with biopsy-proven vasculitis, approximately 10 months into his treatment. This resolved after azathioprine discontinuation and has not recurred to date after subsequent administration of 6-mercaptopurine. This case highlights the need for continued monitoring for delayed hypersensitivity reactions to azathioprine after initiation of therapy.
Keywords: autoimmune hepatitis; azathioprine; hypersensitivity; vasculitis.
© 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of The American College of Gastroenterology.