Q. What causes Kawasaki disease?
A. To date, no cause of Kawasaki disease has been identified. Most experts agree that an environmental trigger, possibly an infectious agent (such as a virus or bacteria), is likely, although genetic predisposition plays an important role and could explain why the disease occurs more frequently among persons of Asian ancestry. There is no evidence that the disease is contagious.
Q. How did the disease get its name?
A. The disease is named after a Japanese pediatrician who described this particular pattern of signs and symptoms in 1967. Since then, Kawasaki disease has been found to occur most frequently among Japanese children. In the United States, the disease has been reported in all racial and ethnic groups but occurs most often among children of Asian-American background.
Kawasaki disease is not a rare illness, and the exact number of cases which occur in the United States has not been determined. However, in San Diego County, the disease attacks 20-30 out of every 100,000 children less than 5 years of age. The disease can occur in clusters or localized outbreaks, usually in the winter and spring.
Q. What are the signs and symptoms?
A. Fever and irritability often occur first. The fever has a rapid onset and fluctuates from moderate (101 to 104 F) to high (above 104). Lymph nodes in the neck may become swollen.
A rash usually appears early in the illness; some patients may develop an accentuated rash in the groin. Often vivid red in appearance, the rash is composed of either poorly defined spots of various sizes or larger masses of merging spots. Fever continues to rise and fall, possibly for up to three weeks. Bloodshot eyes without discharge develop during the first week of illness.
A child’s tongue may be red and show small, raised bumps (papillae); a condition called “strawberry tongue” because the enlarged papillae resemble the seeds on a strawberry’s surface. The lips become dry and cracked and often take on a bright red color. Mucous membranes of the mouth turn a darker red than usual.
The palms of the hands and soles of the feet often turn bright red. Hands and feet can swell. Occasionally, a child may develop a stiff neck. The child usually has great difficulty getting comfortable and remains irritable as a result of the multiple signs and symptoms.
When the fever subsides, the rash, red eyes and the swollen lymph nodes usually disappear. Skin starts to peel around the toenails and fingernails, often beginning during the third week of illness. The skin on a hand or foot may peel off in large pieces or even a single piece (much as a snake sheds its skin). Knees, hips, and ankles can become painful and the child may have difficulty walking.
Occasionally, joint pain and inflammation persist after other symptoms have disappeared. Transverse (horizontal) depressed lines on fingernails and toenails, which occur during the illness, may be visible for months afterward until the nails grow out.
Q. How does a doctor determine if a child has Kawasaki disease?
A. A physician makes a diagnosis of Kawasaki disease after carefully examining a child, observing signs and symptoms, and after ruling out the possibility of other diseases that can cause similar signs. Blood tests are used to detect mild anemia, a white-blood-cell count above normal, and an elevated erythrocyte sedimentation rate which indicates blood vessel inflammation. A sharp rise in the number of platelets, the major clotting element in the blood, may also be detected.
Urine tests may reveal unusual white blood cells in the urine. Irregular heart rhythms (arrhythmias) and evidence of heart muscle strain, indicating involvement of the heart, can be detected by an electrocardiogram (EKG). Echocardiography (a sound wave diagnostic test of heart and blood vessel structure and function) is necessary to evaluate possible damage to the heart or large blood vessels (coronary arteries).
Q. Are there any complications from treatment?
A. Complications from treatment are rare. Although gamma globulin is derived from human blood, viruses such as HIV (the AIDS virus) cannot be transmitted by gamma globulin infusion. Hepatitis C virus has been transmitted by intravenous gamma globulin, but those products have been taken off the market. Occasionally, chills and fever may occur during the infusion. This is treated by interrupting the infusion and giving an antihistamine before restarting.
High doses of aspirin may sometimes cause abdominal pain, gastrointestinal bleeding, and ringing in the ears. Aspirin should be discontinued if any of these signs or symptoms appears. Reye Syndrome is a rare complication of aspirin therapy that can occur in children exposed to chicken pox or influenza virus while they are taking high doses of aspirin. Low-dose aspirin carries no risk of Reye Syndrome.
If diagnostic tests reveal the presence of an aneurysm (dilated segment of the coronary artery) or any other heart or blood vessel abnormality, medical or surgical treatment may be needed. Your doctor may recommend that a cardiologist (a physician who specializes in heart problems) monitor a heart or blood vessel problem for several years following recovery from Kawasaki disease.
Q. What can I expect once my child comes home from the hospital?
A. After coming home from the hospital, you may notice that your child continues to be tired and has a poor appetite for about 1 to 2 weeks. However, unless you have been specifically told otherwise by your doctor, you should not attempt to limit your child’s activity or diet.
Q. You should call your doctor immediately, however, if fever and other signs of Kawasaki disease (e.g. rash, red eyes) return. ‘
A. For all signs and symptoms, see question 3 above.
Note: Routine immunization for measles, mumps, and rubella (MMR) should be delayed for 12 months, following gamma globulin treatment. Tenderness or swelling of the large joints (elbows, knees) and peeling of the fingertips and toes are a normal part of the recovery, but should resolve after approximately three weeks.
Q. Can my child contract this disease in the future?
A. Rarely, Kawasaki disease can reoccur months to years after the initial disease (in Japan, recurrences have been reported in only 4.3 percent of all cases). Should the signs and symptoms described earlier in this pamphlet reoccur, call your doctor immediately.
Q. Can Kawasaki disease be prevented?
A. Unfortunately, at this time, Kawasaki disease cannot be prevented. However, programs such as our Kawasaki Disease Research Center in are working in conjunction with researchers throughout the United States and Japan to further understand this mysterious disease.
For more information, contact Dr. Jane Burns at 858-246-0155 or email firstname.lastname@example.org.