Article: Kawasaki disease

Kawasaki disease, also known as mucocutaneous lymph node syndrome, mucocutaneous lymph node disease, infantile polyarteritis and Kawasaki syndrome, is a poorly-understood non-contagious illness that affects the mucous membranes, lymph nodes, blood vessel walls, and the heart. It was first described in 1967 by Dr. Tomisaku Kawasaki.

Incidence, causes, and risk factors

Kawasaki disease occurs mainly in Japan, though its incidence in the United States is increasing. Kawasaki disease is predominantly a disease of young children, with 80% of patients younger than 5 years of age, but no other contributing factors are known.

The causative agent of Kawasaki disease is still unknown. But current etiological theories center on immunological causes for the disease. Much research is being performed to discover a definitive toxin or antigenic substance, possibly a superantigen, that is the specific cause of the disease.

The cardiac involvement and complications are, by far, the most important aspect of the disease. Kawasaki disease can cause vasculitis (inflammation of blood vessels) in the coronary arteries and subsequent coronary artery aneurysms. These aneurysms can lead to myocardial infarction (heart attack) even in young children. About 20–40% of children with Kawasaki disease will have evidence of vasculitis with cardiac involvement.

Kawasaki disease often begins with a high and persistent fever that is not very responsive to normal doses of acetaminophen or ibuprofen. The fever may persist steadily for up to two weeks. The children develop red eyes, red mucous membranes in the mouth, red cracked lips, a "strawberry tongue" and swollen lymph nodes. Skin rashes may occur early in the disease and peeling of the skin in the genital area, hands, and feet (especially around the nails and on the palms and soles) may occur.

Symptoms

• High-grade fever (greater than 39 °C or 102 °F; often as high as 40 °C or 104 °F) that is unresponsive to medication and lasts more than three days (persistent fever lasting at least five days is considered a hallmark sign)
• Extremely bloodshot or red eyes (conjunctivitis without pus or drainage, also known as "conjunctival injection")
• Bright red, chapped, or cracked lips
• Red mucous membranes in the mouth
• Strawberry tongue, white coating on the tongue or prominent red bumps (papillae) on the back of the tongue
• Red palms of the hands and the soles of the feet
• Swollen hands and feet
• Peeling palms and soles (later in the illness); peeling may begin around the nails
• Rashes similar to erythema multiforme (rash, NOT blister-like, on the trunk)
• Swollen lymph nodes (frequently only one lymph node is swollen), particularly in the neck area
• Joint pain (arthralgia) and swelling, frequently symmetrical
• Petechiae (small pin-point sized red dots on the skin, suggesting subcutaneous capillary bleeding)

Signs and tests

A physical examination will demonstrate many of the symptoms listed above. Procedures such as ECG and echocardiography may reveal signs of myocarditis, pericarditis, arthritis, aseptic meningitis, and coronary vasculitis.

Tests include:

• Angiography
• Complete blood count (CBC)
• Erythrocyte sedimentation rate (ESR)
• Electrocardiogram
• Echocardiogram
• Chest x-ray
• Urinalysis
  • May show pus in the urine (pyuria)
  • May show protein in the urine (proteinuria)

Treatment

Children with Kawasaki disease are hospitalized and care is normally shared between pediatric cardiology and infectious disease specialists, although no infectious agent has been demonstrated. It is imperative that treatment be started as soon as the diagnosis is made to prevent damage to the coronary arteries, heart, and eyes.

Intravenous gamma globulin is the standard treatment for Kawasaki disease and is administered in high doses with marked improvement usually noted within 24 hours.

Salicylate therapy, particularly aspirin, remains an important part of the treatment but salicylates alone are not as effective as IV gamma globulin.

Prognosis

With early diagnosis and treatment, full recovery can be expected. However, about 2% of patients die from complications of coronary vasculitis. Some doctors recommend that patients who have had Kawasaki disease should have an echocardiogram every 1–2 years to screen for progression of cardiac involvement. Treatment is by giving intravenous immunoglobulin.

Complications

Complications involving the heart, including coronary vasculitis and aneurysm, can cause acute myocardial infarction later in life or at a young age.

Reference

• Kawasaki T. Acute febrile mucocutaneous syndrome with lymphoid involvement with specific desquamation of the fingers and toes in children (in Japanese). Arerugi 1967;16:178-222. PMID 6062087.