A 40-year-old man with a ...

A 40-year-old man with a history of melanoma and metastases in the lymph nodes presented to the emergency department with complaints of a rash. He had been undergoing nivolumab/ipilimumab treatment and experienced a localised erythematous rash two weeks after his first dose of immunotherapy. The patient had a medical history of rectal adenocarcinoma, hypertension, obesity, and sinusitis. Aside from nivolumab, his only other medication was amlodipine, which had been started a week before his presentation. Upon examination, he had a widespread rash and was found to have hyperglycemia, leading to the consideration of ICI-DM. The rash was thought to be a drug reaction to amlodipine, and biopsies confirmed a lichenoid drug eruption. Candesartan replaced amlodipine for hypertension, and he was diagnosed with diabetes and prescribed metformin and insulin. On follow-up, his HbA1c remained elevated, his insulin regimen was escalated, and semaglutide was commenced. The patient continued nivolumab therapy as scheduled.