Merck Manuals: What Parents Need to Know About Kawasaki Disease

RAHWAY, N.J., March 26, 2026 /PRNewswire/ -- Kawasaki disease is an autoimmune condition that causes inflammation of blood vessels throughout the body. It is rare, but without prompt treatment it can lead to serious complications.

In a new editorial from MerckManuals.com, Jay Mehta, M.D., of the Perelman School of Medicine at The University of Pennsylvania, answers common questions parents have about Kawasaki disease, including symptoms to watch for and when to see a doctor.

Who is at risk for Kawasaki disease?

Most children with Kawasaki disease are younger than five years old, says Mehta. Rarely, infants under four months of age, adolescents, and adults can develop the disease. Boys are affected slightly more often than girls.

The cause of Kawasaki disease is unknown, says Mehta. There are likely a number of triggers, including viral infections. Like other autoimmune conditions, genetics are likely a component, but the exact role they play is unknown.

What are the signs of Kawasaki disease?

For a typical case in a child between the ages of two to six years old, most will have a fever greater than 100.4° F (38° C) for five or more days, says Mehta. They will also have at least four of the following five symptoms:

• Red eyes with no discharge
  
  
• Reddened, dry, cracked lips and a red "strawberry" tongue
  
  
• Swelling, redness or dark purple color, and, eventually peeling of the hands and feet
  
  
• Red, purplish, or reddish-brown, patchy rash over the trunk
  
  
• Swollen, tender lymph nodes in the neck

In children under six months of age, the only symptom may be prolonged fever, or infants may have just one or two of the most common signs, says Mehta. At the same time, it's important to note that there are many more common causes of fever in children than Kawasaki disease, so not all fevers mean that a child has Kawasaki disease.

Why is prompt treatment so important?

The inflammation that defines Kawasaki disease can be especially dangerous if it affects blood vessels around the heart, says Mehta. In fact, Kawasaki disease is the most common cause of acquired coronary artery disease in children. Prompt treatment substantially reduces the risk of coronary artery disease.

The standard treatment for Kawasaki disease is pooled immune globulin given intravenously, says Mehta. Often, patients feel better and the fever reduces after a single infusion. Doctors will also focus on treating the fever and other symptoms and preventing coronary artery aneurysms.

When should parents call a doctor?

Anytime a child has a fever, it's important to be vigilant, says Mehta. If the fever has lasted for five days, calling the child's pediatrician is a good next step. At this point, a viral infection is still the more likely cause (remember Kawasaki disease is rare and typically has other more distinguishing symptoms).

After five days of fever, in most cases, the doctor will recommend that the child be seen by a health care professional. In general, pediatricians are very familiar with Kawasaki disease. They'll know what symptoms to look for and be able to recommend the right next steps.

To read more of Mehta's insights on Kawasaki disease, visit this editorial on MerckManuals.com.

About The Merck Manuals and MSD Manuals

First published in 1899 as a pocket-sized reference for physicians and pharmacists, The Merck Manual has evolved into one of the world's most trusted and widely-used medical resources. Today, it serves professionals and consumers alike with expert-authored, regularly updated medical content. Available in 16 languages and reaching nearly 250 countries, The Manuals offer far more than text. The website and mobile apps feature an ever-growing collection of videos, podcasts, infographics, and interactive 3D models designed for medical professionals, students, veterinarians, and curious consumers. For over a century, The Merck Manual has been fully committed to making reliable medical knowledge accessible to everyone, everywhere. Access The Manuals online in the United States and Canada at MerckManuals.com, and worldwide at MSDManuals.com.

About Merck

At Merck, known as MSD outside of the United States and Canada, we are unified around our purpose: We use the power of leading-edge science to save and improve lives around the world. For more than 130 years, we have brought hope to humanity through the development of important medicines and vaccines. We aspire to be the premier research-intensive biopharmaceutical company in the world – and today, we are at the forefront of research to deliver innovative health solutions that advance the prevention and treatment of diseases in people and animals. We foster a diverse and inclusive global workforce and operate responsibly every day to enable a safe, sustainable and healthy future for all people and communities. For more information, visit www.merck.com and connect with us on X (formerly Twitter), Facebook, Instagram, YouTube and LinkedIn.

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SOURCE The Merck Manuals