Blue Toes at High Altitude: Peripheral Cyanosis

At altitudes >2,500 meters, acute mountain sickness is usually self-limiting, presenting with hypoxia and pulmonary edema.1 Chronic mountain sickness results in pulmonary hypertension and the development of congestive cardiac failure.1,2 Hypoxemia is associated with signs of peripheral cyanosis. Blue toe syndrome is a common presentation of peripheral ischemia due to occlusion of small caliber peripheral vessels. The differential diagnosis includes atheroembolism, thromboembolism, and vasospastic conditions.