Dear Doctors: What can you tell me about Kawasaki disease? I read that children who had COVID-19 are getting it. But I thought children were supposedly safe from the virus. Why has that changed?
Dear Reader: You’ve broached two important topics, and we’ll take them in reverse order. As we’ve mentioned here before, every bit of information about the novel coronavirus, which we all first heard about in the final days of 2019, has been learned in real time. No one had ever seen this specific virus before, so everything about it was a mystery. This included its genetic and physical makeup, how it’s transmitted, who it affects, how it enters the body and how the body responds once an infection is launched. Our understanding of the virus and COVID-19, which is the disease that it causes, continues to evolve on a daily, and sometimes hourly, basis.
You’re correct that at the start of the pandemic, COVID-19 was known primarily as a viral pneumonia. It’s also true that doctors saw significantly fewer cases in children than among adults. People 18 and younger have accounted for only 2% of confirmed cases of COVID-19, and they often experience mild symptoms.
However, as doctors continue to treat patients, the knowledge base about the disease and its many symptoms expands. Now, emerging data points to the novel coronavirus as the cause of a potentially dangerous inflammatory condition in children. Referred to in the U.S. as multisystem inflammatory syndrome in children, or MIS-C, it involves inflammation in the heart, blood vessels, eyes and skin. Although it’s similar to Kawasaki disease, a rare inflammatory illness often seen in infants and young children, it’s not the same thing. Kawasaki disease is a condition in which high levels of inflammation affect the blood vessels that serve the heart. Untreated, it can result in damage that is life-threatening.
Symptoms of MIS-C include fever, swollen lymph nodes in the neck, a skin rash, pink eye, redness of the lips and tongue, intestinal distress, inflammation leading to poor organ function that can include the kidneys or heart, inflammation of the blood vessels and joint pain. The two most common symptoms of COVID-19 in adults, which are shortness of breath and a dry, hacking cough, often don’t show up in children. Doctors in 19 states have reported cases of the new syndrome, including hard-hit New York, New Jersey and California. The condition is also being seen in Europe and the United Kingdom.
Researchers don’t yet know what triggers the inflammatory syndrome, which is not caused directly by the novel coronavirus. However, many of the affected children are testing positive for COVID-19 antibodies. This suggests a link between MIS-C and the novel coronavirus. Some researchers suspect the syndrome is a delayed response by the immune system.
So far, the syndrome is rare, and most children are not seriously affected. However, new cases continue to emerge. This has prompted the Centers for Disease Control and Prevention to prepare a national alert with detailed information on symptoms, so that the syndrome can be quickly identified and treated.
Eve Glazier, M.D., MBA, is an internist and associate professor of medicine at UCLA Health. Elizabeth Ko, M.D., is an internist and assistant professor of medicine at UCLA Health.
