Man with impaired consciousness and blue tongue

A 62-year-old man with a history of hyperuricaemia and major depressive disorder was brought to the emergency department at night with impaired consciousness. Ten days prior, he experienced left knee pain that disrupted sleep, leading to increased intake of hypnotics. On presentation, he was lethargic with a swollen left knee and a striking blue discolouration of the tongue ( figure 1). Laboratory findings revealed elevated C reactive protein (31.2 mg/dL) and normoglycaemia. Arthrocentesis confirmed gout.