Kawasaki Disease

Kawasaki disease (KD), is an acute febrile illness of unknown etiology that primarily affects children younger than 5 years of age. The disease was first described in Japan by Tomisaku Kawasaki in 1967. Clinical signs include fever, rash, swelling of the hands and feet, irritation and redness of the whites of the eyes, swollen lymph glands in the neck, and irritation and inflammation of the mouth, lips, and throat.

KD occurs worldwide, with the highest incidence in Japan, and it most often affects boys and younger children. In the continental United States, population-based and hospitalization studies estimate an incidence of KD ranging from 9 to 19 per 100,000 children under 5 years of age. In the year 2000, approximately 4248 hospitalizations with KD were reported among children under 18 in the US, of which 3277 (77%) were for children under 5 years of age.

Classically, five days of fever plus four of five diagnostic criteria must be met to establish the diagnosis. The criteria are: erythema of the lips or oral cavity or cracking of the lips, rash on the trunk, swelling or erythema of the hands or feet and red eyes (conjunctival injection).

KD can only be diagnosed clinically as no specific laboratory test exists for this condition. It is difficult to establish the diagnosis, especially early in the course of the illness, and frequently children are not diagnosed until they have seen several health-care providers. Many other serious illnesses can cause similar symptoms, and must be considered in the differential diagnosis, including childhood mercury poisoning (infantile acrodynia).

Many of the same physical characteristics of KD are also present in children diagnosed with acrodynia, or Pink Disease which results from exposure to mercury. Acrodynia is thought to be a form of hypersensitivity to mercury which was common in the early 1900’s from the use of mercury in infant teething powders.