The most severe symptoms of multisystem inflammatory syndrome in children — a rare but serious condition related to COVID-19 — resolved within six months for most patients, though less debilitating symptoms lingered for some, according to a small study published May 24 in The Lancet Child & Adolescent Health.
Researchers at Great Ormond Street Hospital in London observed 46 children who were admitted for the condition between April 4 and Sept. 1, 2020. Specialists followed up with the patients six weeks and six months after readmission. Patients were a mean age of 10.2 years old, and eight had pre-existing comorbidities.
While hospitalized, all patients had systemic inflammation, and most experienced severe symptoms including heart abnormalities. Within six months, systemic inflammation resolved in all patients except one, the findings showed. Two patients still had heart abnormalities and six were experiencing gastrointestinal symptoms.
For 18 of the children, less severe symptoms lingered, such as muscle weakness and fatigue, and 15 experienced severe emotional difficulties including anxiety. Researchers also conducted a six-minute walking test at six months and found 18 patients scored in the bottom 3 percent for their age and sex. They could not confirm whether this was related to MIS-C since the study did not include a control group.
"These findings can hopefully signal cautious optimism that many of the most severe effects of (MIS-C) appear to resolve within six months," Dr. Justin Penner, study co-author and pediatric infectious disease specialist at the hospital, told CNN. "However, the persisting fatigue, difficulty exercising, and mental health effects we saw in some children, which can interfere with daily lives, must be closely monitored and patients should continue to be supported by medical teams with a range of specialisms."
More than 3,700 people under the age of 20 have developed the condition and 35 have died as of May 3, according to the CDC. Physicians from several hospitals told CNN that while more research is needed, the study's findings are mostly in line with what they've seen among former MIS-C patients they've followed up with.