26711 Impact of biopsy and provider training on diagnostic accuracy of cutaneous immune-related adverse events

Introduction: Cutaneous immune-related adverse events (cirAEs) represent one of the most common side effects of immune checkpoint inhibitor (ICI) therapy, occurring in an estimated one-third of treated patients. Despite diagnostic difficulty arising from clinical heterogeneity, cirAEs are infrequently biopsied and managed by a range of providers with varying oncodermatology expertise. The influence of these factors on the accuracy of cirAE diagnosis remains unclear. We sought to address this gap by evaluating rates of change in clinical diagnosis following biopsy, both overall and among different dermatology provider groups.