How do you approach less common cutaneous/mucosal toxicities from EGFR TKI and monoclonal antibody therapies, such as ocular (keratitis and conjunctivitis) and genital mucositis (vulvovaginitis and balanitis)?

I have a patient with metastatic colon ca who was on pembrolizumab for ~16 months with NED who developed grade 3 oral/upper GI mucositis felt to be an autoimmune AE after extensive work-up. He very gradually responded to high dose prednisone followed by a slow taper that took several months due to f...