Durvalumab-associated vasculitis presenting as 'the blue toe syndrome'

Durvalumab is a selective, high-affinity human immunoglobulin monoclonal antibody in a class called check point inhibitors, that blocks PD-L1 on tumour cells. Despite clinical success in increasing progression-free survival rates in patients with stage III non-small-cell lung cancer, durvalumab has been associated with immune-related side effects such as pneumonitis and colitis. We present a case of an 84-year-old woman with acral vasculitis presenting as blue toe syndrome, associated with prolonged use of durvalumab. After 1 year of fortnightly durvalumab therapy postchemoradiation therapy, the patient came in with a left blue big toe, and later developed bilateral livedo racemosa. The diagnosis of durvalumab-associated vasculitis was made and treatment with prednisolone was started with clinical improvement.