There are three stages of Kawasaki disease, and each stage has its own associated signs and symptoms. The classic symptom of Kawasaki disease is a persistent high fever (sometimes up to 104˚F) that lasts for at least five days and does not respond to fever-reducing medications such as acetaminophen. In some cases, the fever may last for up to two weeks.

Because there is no lab test for Kawasaki disease, the U.S. Centers for Disease Control and Prevention (CDC) has developed guidelines to help physicians. A diagnosis can be made if a child has a persistent high fever, combined with four of the five remaining signs and symptoms associated the acute phase. These include: 

Stage 1: Week 1, the Acute Phase 

Stage 2: Weeks 2 to 12, the Subacute Phase 

Stage 3: When symptoms disappear, convalescence

Major aneurysms in the later stages of Kawasaki disease could lead to a more immediate threat of complications. However, death as a direct result of this condition is relatively infrequent.

The usual duration of an episode of Kawasaki disease is six to eight weeks. During the healing period, which begins 45 days after onset and may take a year to complete, the body is able to heal most of the cardiovascular damage it may have sustained. However, damage to the coronary arteries may remain and could increase the risk of heart attack in adulthood. In general, patients with confirmed coronary artery aneurysms will require long-term follow-up. Even without signs of damage by standard imaging techniques, there may be microscopic changes in the walls of these arteries or in the tissues surrounding the arteries.