Pre-existing conditions, GI symptoms help distinguish MIS-C from COVID-19 pneumonia
While most children with multisystem inflammatory syndrome are previously healthy, those hospitalized with severe COVID-19 pneumonia typically have pre-existing conditions, such as diabetes or obesity, according to data.
Other factors that may help distinguish the two include respiratory distress, which is typically present in children with COVID-19, and abdominal pain, vomiting, or diarrhea, which are common in juveniles with MIS-C.
“In children infected with the coronavirus, distinguishing between active infection and those who develop a post-infectious hyper-inflammatory response, multisystem inflammatory syndrome in children (MIS-C), is important therapeutically,” Randy Q. Cron, MD, PhD, of the University of Alabama at Birmingham, told Healio Rheumatology.
Writing in Pediatric Rheumatology, Cron and colleagues noted that, unlike other areas in the United States, where a peak in COVID-19 cases is followed by a peak in MIS-C cases, Alabama has experienced “a consistent and prolonged spread of COVID-19 and MIS-C cases occurring simultaneously.”
“This simultaneous spread has caused diagnostic uncertainty in the pediatric population, as each disease process can have non-specific signs, symptoms, and laboratory findings at presentation,” they wrote.
To compare the disease processes of COVID-19 and MIS-C, and help frontline providers distinguish between the two quickly and efficiently, Cron and colleagues conducted a retrospective chart review. This review included all 111 patients between the ages of 0 and 22 years diagnosed and hospitalized with COVID-19 infection and MIS-C at the Children’s of Alabama Hospital, in Birmingham, from April 1, 2020, through Sept. 1, 2020. Cases were identified and verified using diagnostic codes and current CDC definitions.
The researchers reviewed all clinical notes for documentation of COVID-19 pneumonia or MIS-C. Demographics, presenting signs and symptoms, prior exposure to or testing for COVID-19, laboratory data, imaging, treatment modalities and response to treatment were assessed using clinical notes and electronic medical records.
According to the researchers, 74 of the 111 included patients were classified as mild COVID-19 cases, eight were moderate COVID-19 cases, and another eight were severe COVID-19 cases. Meanwhile, 10 were identified as mild MIS-C cases, and 11 had severe MIS-C. All groups were predominantly male, with Black and Hispanic individuals overrepresented relative to the demographics of Alabama.
Most patients with MIS-C were healthy at baseline, while most with COVID-19 demonstrated at least one underlying disease. In addition, fever, rash, conjunctivitis and gastrointestinal symptoms were predominant in those with MIS-C, whereas patients with COVID-19 typically presented with respiratory symptoms and were more likely to have a positive SAR-CoV-2 polymerase chain reaction and require respiratory support upon admission. Those in the COVID-19 group also demonstrated higher lactate dehydrogenase levels on admission.
Meanwhile, those with MIS-C had lower sodium levels and higher levels of C-reactive protein, erythrocyte sedimentation rate, d-dimer and procalcitonin. They also demonstrated coronary artery changes on echocardiography more often than those with COVID-19.
Despite these differences, the two groups were similar in symptomatic prodrome duration, as well as in exposure history to COVID-19. However, patients with MIS-C demonstrated a longer duration between presentation and exposure history.
“Children with COVID-19 pneumonia may benefit initially from antiviral approaches — remdesivir, for example — where later in the disease course glucocorticoids such as dexamethasone may help with the following cytokine storm,” Cron said. “Children with MIS-C often present in shock requiring fluid resuscitation and sometimes cardiovascular pressor support.”
“Younger children — typically younger than 6 years of age — often share features with Kawasaki Disease, such as conjunctivitis, rash and cervical adenopathy, and are at risk of coronary artery involvement,” they added. “Thus, intravenous immunoglobulin is important treatment to help prevent this. Many children will also benefit from moderate to high-dose glucocorticoids as well.”