Kawasaki disease is an autoimmune disease that causes inflammation of blood vessels throughout the body. It most commonly affects children under 5 years old, especially of Japanese and Korean descent. Signs include a persistent high fever for at least 5 days along with redness and swelling of the eyes, lips, mouth, hands, and feet. If not treated within 10 days, it can lead to heart problems such as irregular heartbeat or aneurysms of the coronary arteries. While the cause is unknown, it is thought to be due to an infectious agent and occurs most often in winter and spring. Early treatment with medicines can cure it and prevent heart damage.