ACR issues guidances for MIS-C and pediatric rheumatic disease during pandemic


Management of MIS-C associated with COVID-19

The task force that developed guidance for the new inflammatory condition recently linked to SARS-CoV-2 infections in children included nine pediatric rheumatologists, two adult rheumatologists, two pediatric cardiologists, two pediatric infectious disease specialists, and one pediatric critical care physician.

The guidance includes a figure for the diagnostic pathway in evaluating children suspected of having MIS-C and extensive detail on diagnostic work-up, but the task force intentionally avoided providing a case definition for the condition. Existing case definitions from the Centers for Disease Control and Prevention, World Health Organization, and the United Kingdom’s Royal College of Paediatrics and Child Health differ from one another and are based on unclear evidence, Dr. Henderson noted. “We really don’t have enough data to know the sensitivity and specificity of each parameter, and until that’s available, we didn’t want to add to the confusion,” she said.

The guidance also stresses that MIS-C is a rare complication, so patients suspected of having the condition who do not have “life-threatening manifestations should undergo diagnostic evaluation for MIS-C as well as other possible infectious and noninfectious etiologies before immunomodulatory treatment is initiated,” the guidance states.

Unless a child is in shock or otherwise requires urgent care, physicians should take the time to complete the diagnostic work-up while monitoring the child, Dr. Henderson said. If the child does have MIS-C, the guidance currently recommends intravenous immunoglobulin (IVIG) and/or glucocorticoids to prevent coronary artery aneurysms, the same treatment other institutions have been recommending.

“We don’t have rigorous comparative studies looking at different types of treatments,” Dr. Henderson said, noting that the vast majority of children in the literature received IVIG and/or glucocorticoid treatment. “Often children really responded quite forcefully to those treatments, but we don’t have high-quality data yet to know that this treatment is better than supportive care or another medication.”

Dr. Henderson also stressed the importance of children receiving care at a facility with the necessary expertise to manage MIS-C and receiving long-term follow-up care from a multidisciplinary clinical team that includes a rheumatologist, an infectious disease doctor, a cardiologist, and possibly a hematologist.

“Making sure children are admitted to a hospital that has the resources and are followed by physicians with expertise or understanding of the intricacies of MIS-C is really important,” she said, particularly for children with cardiac involvement. “We don’t know if all the kids presenting with left ventricular dysfunction and shock are at risk for having myocardial fibrosis down the line,” she noted. “There is so much we do not understand and very little data to guide us on what to do, so these children really need to be under the care of a cardiologist and rheumatologist to make sure that their care is tailored to them.”

Although MIS-C shares overlapping symptoms with Kawasaki disease, it’s still unclear how similar or different the two conditions are, Dr. Henderson said.

“We can definitely say that when we look at MIS-C and compare it to historical groups of Kawasaki disease before the pandemic, there are definitely different features in the MIS-C group,” she said. Kawasaki disease generally only affects children under age 5, whereas MIS-C patients run the gamut from age 1-17. Racial demographics are also different, with a higher proportion of black children affected by MIS-C.

It’s possible that the pathophysiology of both conditions will turn out to be similar, particularly given the hypothesis that Kawasaki disease is triggered by infections in genetically predisposed people. However, the severity of symptoms and risk of aneurysms appear greater with MIS-C so far.

“The degree to which these patients are presenting with left ventricular dysfunction and shock is much higher than what we’ve seen previously,” Dr. Henderson said. “Children can have aneurysms even if they don’t meet all the Kawasaki disease features, which makes it feel that this is somehow clinically different from what we’ve seen before. It’s not just the kids who have the rash and the conjunctivitis and the extremity changes and oral changes who have the aneurysms.”

The reason for including both IVIG and glucocorticoids as possible first-line drugs to prevent aneurysms is that some evidence suggests children with MIS-C may have higher levels of IVIG resistance, she said.

Like Dr. Wahezi, Dr. Henderson emphasized the necessarily transient nature of these recommendations.

“These recommendations will almost certainly change based on evolving understanding of MIS-C and the data,” Dr. Henderson said, adding that this new, unique condition highlights the importance of including children in allocating funding for research and in clinical trials.

“Children are not always identical to adults, and it’s really important that we have high-quality data to inform our decisions about how to care for them,” she said.

Dr. Wahezi had no disclosures. Dr. Henderson has consulted for Sobi and Adaptive Technologies. The guidelines did not note other disclosures for members of the ACR groups.

SOURCES: COVID-19 Clinical Guidance for Pediatric Patients with Rheumatic Disease and Clinical Guidance for Pediatric Patients with Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with SARS-CoV-2 and Hyperinflammation in COVID-19


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