Read the parent’s guide to Kawasaki disease

Endless coughs and sneezes, runny noses, and unexplained itchy bumps—kids seem to be a magnet for germs. In our parent’s guide to childhood illnesses, we talk about the symptoms and treatments for the most common conditions. Read the full series here.

What is Kawasaki disease? | Risk factors | Symptoms | Diagnosis | Treatments | Prevention | COVID-19

When a friend shared that her son had been experiencing an unexplained high fever with some unusual symptoms for over five days, I told her that it sounded as though her son had Kawasaki disease. Like most people, my friend had never heard of this illness.

It’s a dangerous gap in knowledge. Because Kawasaki disease requires timely treatment, every parent should know the symptoms—and how to get a diagnosis. Fortunately, my friend’s son received treatment within the right time window and made a full recovery.

What is Kawasaki disease?

Kawasaki disease (KD), also known as Kawasaki syndrome, is a condition that causes vasculitis, or inflammation of the blood vessels. More than 4,200 American children are diagnosed with KD each year. It is the leading cause of acquired heart disease in infants and young children in the United States. Swift diagnosis and treatment are necessary to prevent it from becoming serious.

“Kawasaki disease can be quite dangerous if it goes untreated,” says Ashanti Woods, MD, a pediatrician at Mercy Medical Center in Baltimore. “If untreated, or if it is treated late in the process, KD can lead to serious changes of the heart, including aneurysm of the coronary artery. The coronary artery is responsible for providing oxygen to the heart. Therefore, if this artery is negatively affected, it can impact the entire heart.”

Kawasaki disease is not believed to be contagious. Though there isn’t a clear consensus on common causes of KD, there are some theories as to how KD develops.

“The exact cause of Kawasaki disease is not known,” says Soma Mandal, MD, a board-certified internist at Summit Medical Group. “Toxic substances called bacterial superantigens that are produced by Streptococcus or Staphylococcus may trigger an exaggerated response by the immune system.”

Risk factors

KD is primarily a children’s disease. “Kawasaki‘s disease is usually limited to children 5 years of age and under,” Dr. Woods says. “There are some forms of atypical Kawasaki disease that affect slightly older children, but typically adults are spared.”

While KD can affect all genders and ethnicities, boys are 1.5 times more likely than girls to experience KD. Kawasaki disease is more prevalent in Japan and among certain ethnic groups—primarily those of Asian descent. Most children with KD are less than 5 years old. In the continental United States, KD is more common during the winter and early spring.

Kawasaki disease symptoms

The hallmark of KD is a high fever lasting at least five days, that can’t be attributed to anything else. Other symptoms of Kawasaki disease include:

• Red eyes (bloodshot—without discharge)
• Strawberry tongue (white coating and red bumps on the tongue)
• Red, dry, cracked lips
• A pinkish rash on the body, particularly in the groin area
• Purple, red color on the palms of the hands and/or the soles of the feet
• Swollen palms and/or soles of the feet
• Sore throat
• Swollen lymph nodes in the neck

These symptoms may not appear at the same time. Make note of symptoms even if they aren’t present all at once. Other symptoms that can occur include:

• Peeling skin on hands and feet (usually two to three weeks after the fever starts)
• Abdominal pain
• Vomiting
• Diarrhea
• Joint pain

How is Kawasaki disease diagnosed?

“KD is diagnosed based on a child’s clinical presentation and lab work,” Dr. Woods says. “Once a child has a fever for more than five days, the physician or nurse practitioner is aware to look for some other features of Kawasaki disease.”

In addition to an exam, the healthcare professional may choose to run medical tests.

“There are also some laboratory features, such as markers of inflammation, that also fit the picture of Kawasaki disease,” says Dr. Woods. “If a clinician is suspicious for Kawasaki disease, often an echocardiogram (or ultrasound of the heart) will be done to see if there are any changes such as an aneurysm (or ballooning) of the coronary artery.” There is no specific blood test to confirm KD, but lab studies may be helpful to guide the diagnosis.

Kawasaki disease requires urgent medical attention. “Parents should be suspicious for KD if their child has a high fever for five days or longer and several of the symptoms mentioned above,” says Dr. Woods. “If Kawasaki disease is suspected, parents should contact their pediatrician to schedule an appointment. If it is in the middle of the night, a parent should head to the ER.”

Kawasaki disease can be difficult to diagnose, and may require several examinations before a diagnosis is made. If the healthcare provider doesn’t give a KD diagnosis initially, but you suspect it’s KD, do not hesitate to schedule another visit.

The son of the friend did not get a KD diagnosis the first time my friend raised the concern to her doctor. He was diagnosed with KD at a children’s hospital shortly after.

Kawasaki disease treatments

Treatment within 10 days of the beginning of the fever is essential to ensure full recovery. Without treatment, up to 1 in 4 children with KD will sustain damage to their heart, according to the American Heart Association. Untreated or misdiagnosed Kawasaki disease in childhood can lead to heart-related complications in adulthood. There is no specific curative treatment for KS—but the goal of early therapy is to reduce inflammation, arterial damage, and to prevent clotting in those with coronary artery abnormalities. Thankfully, treatment within 10 days significantly decreases the chances of serious complications like heart attack, heart disease, myocarditis, or coronary artery aneurysms.

1. Head to the hospital as soon as possible

Treatment for KD requires a hospital stay of at least 24 hours, and often several days.

2. In-hospital treatment options

“Intravenous immune globulin (IVIG) and aspirin are primarily used in treatment,” says Dr. Mandal. “Risk of IVIG resistance should be determined prior to initiating therapy. Patients who are at high risk for resistance are additionally treated with systemic steroids. Cyclosporine has shown some efficacy for treatment resistant Kawasaki disease or in those patients at higher risk for IVIG resistance.”

Intravenous immunoglobulin acts as an anti-inflammatory, its except mechanism is not known. It is administered via an IV over the course of eight to 12 hours. High-dose aspirin may be started in the hospital and then continued on a low dose at home for six to eight weeks to prevent blood clots. Note: Aspirin should only be given to children under the supervision of a healthcare provider due to the risk of Reye’s syndrome (a condition that can arise when children with a viral illness take Aspirin.)

3. Follow-up exams for the prevention and management of Kawasaki disease complications

Children who have had KD should be given at least two follow-up electrocardiograms by a pediatric cardiologist, usually at two weeks after the beginning of the fever, and again at six to eight weeks after the beginning of the fever. If any abnormal findings show on these tests, more monitoring will be required to check for lingering heart problems.

Thankfully, most kids who receive prompt treatment for KD recover completely. 

How to prevent Kawasaki disease

There is no known way to prevent Kawasaki disease, and it is very rare to get KD more than once.

Can COVID-19 cause Kawasaki disease?

While COVID-19 seems to be less dangerous to children than adults, some kids who contract the novel coronavirus become very ill, very quickly with a condition known as multisystem inflammatory syndrome in children (MIS-C). This new syndrome has symptoms similar to KD.

As this syndrome is new, it is not yet well-understood. More research is being conducted on this rare but serious condition. Children with MIS-C may not test positive for COVID-19. If MIS-C is suspected, seek medical attention immediately.

Kawasaki disease is frightening, but knowledge is power. By knowing what to look for, parents can ensure their children get prompt treatment they need to make a full recovery.