Kawasaki Disease

At a glance

It is a self-limited vasculitic syndrome of unknown etiology, which is characterized by fever, cervical adenopathies, and cardiac anomalies. The presence of the “Strawberry Tongue Pattern” is characteristic of this medical condition. It is the result of vascular inflammation associated with severe and prolonged fever that does not respond to usual therapy. The presence of painful lymphadenopathy in the neck, with large cutaneous rash in the genital area, plus red eyes, lips, palms, or soles. Within 3 weeks of the onset, the skin from the hands and feet may peel. Recovery then typically occurs. The presence of coronary artery aneurysms may develop consequently to this severe vascular inflammation.

Synonym

Mucocutaneous Lymph Node Syndrome.

History

The disorder was first described in 1967 by Tomisaku Kawasaki in Japan.

Incidence

The incidence is estimated in the general population to be between 8 and 67 per 100,000 individuals under the age of 5 years. Asian people are at greater risk. In Japan, it affects 125:100,000. It is estimated that there are 5,000 to 6,000 new cases per year that occur in Japan in comparison with 3,000 in the United States. Males are affected 1.5 times more often than females. Kawasaki disease (KD) is currently the leading cause of acquired heart disease in the United States among children younger than 5 years. Mortality from coronary artery abnormalities, including coronary aneurysms, is reported in 20 to 25% of untreated individuals.

Genetic inheritance

Etiology of KD is unknown. Several possibilities are considered, including an infectious etiology (retrovirus?), an immunologic abnormality, and even a toxic cause (carpet shampoo). Clinical and epidemiologic data support an infectious etiology, but many authors think that an autoimmune component or genetic predisposition also exists.

Pathophysiology

Necrotizing vasculitis of medium-size muscular arteries, including coronary and cerebral vessels. Arteries show focal segmental destruction, with subsequent ectasia and formation of aneurysms in 15 to 25% of children. Several infectious causes of KD have been theorized and include Ebstein-Barr virus, retroviruses, Streptococcus pyogenes and viridans, Staphylococcus, Chlamydia, Propionibacterium, and Pseudomonas species. However, conventional bacterial and viral cultures and serologic studies have not confirmed an infectious cause. Other postulated etiologic agents are immunizations, medications, and environmental agents, such as exposure to rug shampooing agents or house dust mites. The finding of a skewed T-cell receptor response in the myocardium and the coronary arteries led to a search for superantigens, such as toxic shock syndrome toxin-1 produced by Staphylococcus aureus. Immunohistochemical findings lend support to the hypothesis of a proinflammatory cell-mediated immune reaction possibly triggered by a superantigen or a conventional antigen.