A middle-aged man with long-standing Crohn disease maintained in remission on low-dose immunosuppression presented with abdominal pain. Over the following few days he developed a vesicular rash, became dyspnoeic, confused and had two seizures. Despite high-dose intravenous aciclovir, he died. Disseminated varicella zoster virus, the cause of his death, could potentially have been prevented had he received varicella vaccination at an earlier stage.