July 26th, 2020
Classical Kawasaki disease presents with a prolonged fever of ≥5 days, however if >4 of the principal clinical criteria are met, the diagnosis may be made with only 4 days of fever. Without treatment the fever continues for 1 to 3 weeks.
Children with Kawasaki disease can present with extreme irritability. It is unknown why this occurs; a neuro-infectious etiology has been postulated.
Abdominal pain, vomiting, diarrhea and/or jaundice may be seen. This is due to systemic inflammation that often involves multiple organs.
Joint pain and swelling
Joint pain and swelling may occur due to inflammation.
The highest relative risk for Kawasaki disease is in Asian children, especially children of Japanese descent; their risk is almost ten times that of children of Caucasian descent. This suggests a genetic predisposition to the disease.
Kawasaki disease is most common in young children and predominantly affects children <5 years of age. A hypothesis is that an undiscovered infectious etiology could be a possible trigger for the disease, with older individuals having natural immunity to this pathogen.
One percent of patients with Kawasaki disease have a positive family history. There is an increased incidence in siblings of an index case, often within several days of the disease's occurrence in the first child, and an increased concordance rate in identical twins.
This is thought to be due to the interplay of genetics and environment.
Boys with the disease outnumber girls by ≈1.5:1.
Kawasaki disease is most prevalent in the winter and spring. This could be due to an infectious etiology.
Coronary artery aneurysms are a sequela in ≈25% of untreated cases; refractory disease also confers a high risk of developing aneurysms. These can lead to myocardial ischemia and sudden death. The underlying cause is inflammation of the coronary arteries.
Importantly, Kawasaki disease is the most common cause of acquired heart disease in childhood in developed countries.
The incidence of Kawasaki disease shock syndrome is estimated at 7%. This can resemble toxic shock syndrome, and is believed to be multifactorial in origin.