Sunday, May 11, 2008

Kawasaki Syndrome

Kawasaki disease, also known as lymph node syndrome, mucocutaneous node disease, infantile polyarteritis and Kawasaki syndrome, is a poorly understood self-limited vasculitis that affects many organs, including the skin and mucous membranes, lymph nodes, blood vessel walls, and the heart. It does not seem to be contagious. It was first described in 1967 by Dr. Tomisaku Kawasaki in Japan.[1]

Incidence, causes, and risk factors

By far, the highest incidence of Kawasaki disease occurs in Japan (175 per 100,000), 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. Additional risk factors in the United States include Asian race and male sex. The causative agent of Kawasaki disease is still unknown.

However, current etiological theories center primarily 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. An unknown virus may play a role as an inciting factor as well. The cardiac complications are, by far, the most important aspect of the disease. Kawasaki disease can cause vasculitic changes (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. Overall, about 10–18% of children with Kawasaki disease develop coronary artery aneurysms Kawasaki syndrome and risk factors for coronary artery abnormalities: United States, 1994-2003. with much higher prevalence among patients who are not treated early in the course of illness. Kawasaki disease and rheumatic fever are most common causes of acquired heart disease among children in the United States.

Symptoms

Kawasaki disease often begins with a high and persistent fever that is not very responsive to normal doses of paracetamol (acetaminophen) or ibuprofen. The fever may persist steadily for up to two weeks and is normally accompanied by irritability. Affected children develop red eyes, red mucous membranes in the mouth, red cracked lips, a "strawberry tongue", iritis, keratic precipitates (detectable by an ophthalmologist but usually too small to be seen by the unaided eye), and swollen lymph nodes.

Skin rashes 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 in later phases. Some of these symptoms may come and go during the course of the illness. If left untreated, the symptoms will eventually relent, but coronary artery aneurysms will not improve, resulting in a significant risk of death or disability due to myocardial infarction (heart attack). If treated in a timely fashion, this risk can be mostly avoided and the course of illness cut short.
  • High-grade fever (greater than 39 °C or 102 °F; often as high as 40 °C or 104 °F) that normally lasts for more than a week if left untreated.
  • 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
  • Rash which may take many forms, but not vesicular (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
  • Irritability
  • Tachycardia (rapid heart beat)
  • Peeling (desquamation) palms and soles (later in the illness); peeling may begin around the nails

Signs and tests
A physical examination will demonstrate many of the features listed above.beaus lines(transverse grooves on nails)