What Is Kawasaki Disease?
Kawasaki disease is an illness that causes blood vessels to become inflamed, almost always in young children. It's one of the leading causes of heart disease in kids. But doctors can treat it if they find it early. Most children get better without any problems.
Kawasaki Disease Causes and Risk Factors
The inflammation of Kawasaki disease can damage a child's coronary arteries, which carry blood to their heart.
It can also cause problems with lymph nodes, skin, and the lining of a child's mouth, nose, and throat.
Scientists haven't found an exact cause of Kawasaki disease. It might be linked to genes, viruses, bacteria, and other things in the world around a child, such as chemicals and irritants.
The disease probably isn't contagious, but it sometimes happens in clusters in a community. Kids are more likely to get it in the winter and spring.
Other things can raise a child's odds of getting Kawasaki disease, including:
- Age. It usually affects children who are 5 years or younger.
- Sex. Boys are 1.5 times more likely to get it than girls.
- Ethnicity. Children of Asian and Pacific Island descent are more likely to have Kawasaki disease.
Research shows Black children with Kawasaki disease may have different symptoms and respond differently to treatment than White children. One study found this group of kids had more serious inflammation, worse treatment outcomes and more secondary treatments and spent longer in the hospital than White kids.
Kawasaki Disease Symptoms
Kawasaki disease comes on fast, and symptoms show up in phases. Signs of the first phase of Kawasaki disease include:
- High fever (above 101 F) that lasts more than 5 days; it won't go down even if a child takes medication that usually works on fever
- Rash, often between the chest and legs and in the genital or groin area
- Peeling skin on the fingers and toes (usually in weeks two or three of the illness)
- Swelling and redness in hands and bottoms of feet
- Red eyes
- Swollen glands, especially in the neck
- Irritated throat, mouth, and lips
- Swollen, bright red "strawberry tongue"
In the second phase, symptoms include:
- Joint pain
- Belly pain
- Stomach trouble, such as diarrhea and vomiting
- Peeling skin on hands and feet
Kawasaki disease can cause heart trouble 10 days to 2 weeks after symptoms start.
Symptoms tend to go away slowly in the third phase. It might last as long as 8 weeks.
Call your doctor if your child has these symptoms, including a fever between 101 F and 103 F that lasts more than 4 days. Early treatment can help lower their risk of lasting effects.
Kawasaki disease rash
If your child has Kawasaki disease, you'll probably notice a rash in their genital area or in the area between their chest and legs. It's likely to disappear in a week. It's often flat and blotchy but can also have raised bumps. While the rash may look red on light skin, it can be harder to see on darker skin tones.
Kawasaki Disease Diagnosis
Your doctor will do a physical exam and ask about your child's symptoms. They'll look for a long-lasting fever and at least four of these five signs:
- Red eyes
- Dry, cracked, very red lips and a redder-than-normal swollen tongue
- Swollen lymph nodes
- Swollen, discolored skin on your palms and bottom of your feet
They may need to do tests to rule out other illnesses or to see whether the condition has affected your child's heart. These include:
- Heart tests such as electrocardiogram (EKG) and echocardiogram
- Blood tests
- Imaging tests like X-rays and coronary angiogram
Kawasaki disease and COVID-19
Kids who get COVID-19 can also end up with a condition called multisystem inflammatory syndrome (MIS-C). The symptoms of MIS-C such as fever and rash look a lot like the ones of Kawasaki disease. Talk to your child's doctor about any concerning symptoms.
Kawasaki Disease Treatment
Your child may have a lot of pain from the fever, swelling, and skin problems. Their doctor might prescribe medicine to make them feel better, such as aspirin and drugs that prevent blood clots. Don't give your child any drugs without talking to your doctor first.
The doctor will probably also give them immunoglobulin into a vein (intravenous or IV). This has proteins called antibodies to help fight infection. It will lower a child's chance of heart issues when they get it early on in treatment.
Most children start treatment for Kawasaki disease in a hospital because there's a high chance it will cause serious health problems.
After their first treatment, your child may continue to take low-dose aspirin for 6 weeks or more, especially if the artery supplying oxygen-infused blood to their heart widens (called coronary artery aneurysm). Aspirin stops their blood from clotting.
Your child's doctor will likely schedule several follow-up visits to check for signs of heart problems. If they do show signs, your child could need heart health tests and to visit a heart disease specialist.
Kawasaki Disease Complications
Because it involves a child's heart, this illness can be scary. But most kids recover completely and have no lasting problems.
In rare cases, children can have:
- Unusual heart rhythms (dysrhythmia)
- Inflamed heart muscles (myocarditis)
- Damaged heart valves (mitral regurgitation)
- Inflamed blood vessels (vasculitis)
These can lead to other troubles, including weak or bulging artery walls. These are called aneurysms. They could raise a child's risk of artery blockages, which can cause internal bleeding and heart attacks. An echocardiogram can show many of these complications.
In severe cases, a child might need surgery. Infants have a higher risk of other serious health problems. In the U.S., fewer than 1% of children die during the early illness.
Kawasaki Disease Outlook
With treatment, most kids with Kawasaki disease can avoid heart disease and death. Coronary artery aneurysms impact just 6% of kids who've been treated for the condition, and 50% of children with coronary artery problems heal in 1 or 2 years with treatment. Without treatment, heart problems from Kawasaki disease can cause death in 45 days or less after a fever starts.