Population-based study of multisystem inflammatory syndrome associated with COVID-19 found that 36% of children had persistent symptoms

Abstract

Aim: Our aim was to describe the outcomes of multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19.

Methods: This national, population-based, longitudinal, multicentre study used Swedish data that were prospectively collected between 1 December 2020 and 31 May 2021. All patients met the World Health Organization criteria for MIS-C. The outcomes 2 and 8 weeks after diagnosis are presented, and follow-up protocols are suggested.

Results: We identified 152 cases, and 133 (87%) participated. When followed up 2 weeks after MIS-C was diagnosed, 43% of the 119 patients had abnormal results, including complete blood cell counts, platelet counts, albumin levels, electrocardiograms and echocardiograms. After 8 weeks, 36% of 89 had an abnormal patient history, but clinical findings were uncommon. Echocardiogram results were abnormal in 5% of 67, and the most common complaint was fatigue. Older children and those who received intensive care were more likely to report symptoms and have abnormal cardiac results.

Conclusion: More than a third (36%) of the patients had persistent symptoms 8 weeks after MIS-C, and 5% had abnormal echocardiograms. Older age and higher levels of initial care appeared to be risk factors. Structured follow-up visits are important after MIS-C.

Keywords: abnormal echocardiograms; fatigue; intensive care; outcomes; persistent symptoms.

FIGURE 1

Complaints at the 2‐ and 8‐week follow‐up visits. (A) A total of 119 children had a registered 2‐week follow‐up visit and 51 reported any complaint. The most common were fatigue (n = 26), skin manifestations (n = 9), psychiatric or neuropsychiatric problems (n = 8), reduced exercise capacity (n = 8), muscle or joint weakness or pain (n = 7), gastrointestinal symptoms (n = 4), headaches (n = 3) and others (n = 11). (B) A total of 89 children had a registered 8‐week follow‐up visit and 32 reported any complaint. The most common were fatigue (n = 13), muscle or joint weakness or pain (n = 6), headaches (n = 7), gastrointestinal symptoms (n = 7), reduced exercise capacity (n = 6), psychiatric or neuropsychiatric problems (n = 4), skin manifestations (n = 1) and others (n = 9)