Multisystem Inflammatory Syndrome in Children

Inflammatory Syndrome in Children (MIS-C) is a complication associated with COVID-19 infection in children. Most of the symptoms of COVID-19 in children are mild. However, occasionally, it can progress to a rare and serious complication called MIS-C. The estimated incidence is believed to be two per 100,000. As of March 1, CDC reported 2617 cases worldwide and 33 deaths. As of March 24, the number of MIS-C cases in Louisiana is 142, with six deaths.

Most cases occurred in older children and adolescents who were previously healthy. Black and Hispanic children appeared to be disproportionately affected more. Presentation of MIS-C differs from COVID-19 in children as it is a more severe illness. There is a three- to four-week lag for developing this disease after COVID infection, suggesting that MIS-C may represent a post-infectious complication of the virus rather than acute infection. Parents need to be vigilant if their child gets sick again after recovering from COVID within two to six weeks. It is suggested that the syndrome results from an abnormal immune response to the virus. Many affected children have negative PCR testing for COVID but have positive serology.

Clinical manifestations may include persistent fever (up to four to six days), abdominal pain, vomiting, diarrhea, rash, headache, lethargy, confusion, lymph gland swelling, muscle pain, and swollen head and feet. Some children will progress to develop breathing difficulty requiring intubation and mechanical ventilation. Patients with severe illness can also go into shock, requiring IV fluid and medications to support the blood pressure in ICU settings. Cardiovascular dysfunction is most commonly seen, presenting as high heart rate and low blood pressure. Very few patients present with other severe manifestations such as seizures, coma or encephalopathy/altered mental status, The majority of patients, who present with impairment in the functioning of organ systems, require admission to pediatric intensive care.

B l o o d work shows evidence of inflammation in patients with MIS-C; labs show decreased white cell, red cell and platelet counts. Inflammatory markers such as C– reactive protein, erythrocyte sedimentation rate, LDH, D dimer, liver enzymes and ferritin are elevated. Cardiac markers such as troponin are elevated in more than half of these patients.

Initial management includes stabilization of respiratory status, improving heart rate and blood pressure. Antibiotics are started if there is a concern for evidence of concurrent bacterial infection. Various immunosuppressive medications are used to decrease inflammation in MIS-C. These include IVIG followed by steroids. Other therapies such as anakinra or tocilizumab are used in severe, refractory cases.

The prognosis is uncertain as MIS-C is a relatively new entity. Children with MIS-C require intensive care admission. Early intervention and the use of therapies mentioned above are potentially lifesaving.

The best way of preventing MIS-C is by taking steps for the prevention of COVID-19 infection. Guidelines from CDC include frequently washing hands, cleaning and disinfecting surfaces, avoiding close contact with others, limiting in-person playtime, wearing masks (children age 2 or older), and hanging out with very few families in your social bubble.

In summary, MIS-C is a challenging and fatal disease in children. Early recognition is crucial, as a better prognosis is reached with a multidisciplinary team including a pediatric intensivist, infectious disease specialist, cardiologist and rheumatologist.

Anusha Vuppala, MD, is currently a first-year Rheumatology Fellow at LSUHSC, Shreveport. Dr. Vuppala has completed her medicine-pediatric residency training at LSUHSC, Shreveport and is board certified in medicine and pediatrics.

Sarwat Umer, MD, is an associate professor of medicine/pediatrics at the Center of Excellence for Arthritis and Rheumatology in Shreveport, La. Dr. Umer completed her adult rheumatology fellowship at Louisiana State University Health Science Center, Shreveport, and pediatric training at UT Southwestern Medical Center, Dallas.