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- A rare, but potentially deadly, inflammatory illness can affect children who have had COVID-19.
- A small UK study suggests that the most severe symptoms of the disease can resolve within 6 months.
- But some still experienced weakness and fatigue, suggesting follow-up is still needed.
- See more stories on Insider's business page.
The most severe symptoms of an inflammatory syndrome linked with COVID-19 can subside within six months, according to a small study published in the peer-reviewed Lancet Child & Adolescent Health journal on Monday.
The rare disease, known as multisystem inflammatory syndrome in children (MIS-C), can cause inflammation in several organs, including the heart, lung, kidneys, gut, and brain.
It's unclear what triggers the disease, but 99% of the children diagnosed with MIS-C in the US had tested positive for COVID-19, according to the Centers of Disease Control and Prevention.
There have been 3,742 cases of MIS-C in the US since reporting began in 2020, 35 of which were fatal, according to CDC data. The disease is still poorly understood, the agency said.
But new research offers hope that the most severe symptoms of the disease might not be long lived.
Researchers at the specialist pediatric Great Ormond Street Children's hospital in London followed 46 children with severe MIS-C for six months after they were first admitted. The researchers noted that the study did not have a control group, and that the study only looked at severely ill children.
According to the study, the children were first presented with a combination of the symptoms below:
- All had systemic inflammation.
- Most had severe effects on organ systems like the kidneys or the circulatory system.
- Fifteen had heart symptoms.
- Forty-five had gut issues like stomach pains, diarrhea and vomiting.
- Twenty-four had neurological issues like hallucinations, seizures, or problems with balance and muscle control.
But after six months, most of the children appeared to have recovered from the most severe symptoms of the disease, the study said. Here's what the researchers found:
- Only one still had systemic inflammation.
- Two had heart problems, and six had gut issues.
- Eighteen had small neurological abnormalities, but were able to walk normally and carry out day-to-day tasks.
- All but one child were able to return to schooling, in person or online.
However, 18 of the children still reported severe muscle weakness and fatigue, scoring in the bottom 3% of children in that age group on a six-minute walking test, the study said.
And 15 of the children still had emotional issues like anxiety or severe mood changes, according to questionnaires filed out by the children or their parents, as cited in the study.
It is not clear whether these lingering symptoms are due to the disease itself or to the disruption caused by the disease in the children's life, the authors said in a press release, saying they should continue to be followed.
The authors added that it is possible that the symptoms could come back after six months, and the children should continue to be monitored.