A Strategy for Managing Multisystem Inflammatory Syndrome in Children

The clinical profile of multisystem-inflammatory syndrome in Children (MIS-C), a complication of COVID-19, the illness caused by the SARS-CoV-2 virus, continues to evolve. Patients often have elevated C-reactive protein (CRP), D-dimer, and troponin levels, experience symptoms across major organ systems, and in some cases become severely ill. Moreover, MIS-C manifests differently in younger patients than older ones. As studies emerge on the demographics, clinical presentations, and lab values specific to this condition, experts have been crafting algorithms to optimize testing in children suspected of having this novel inflammatory disorder.

The American College of Rheumatology (ACR) in recent draft clinical guidance devised a testing algorithm that outlines a two-tiered approach. ACR recommends that children with fever >38℃, an epidemiologic link to SARS-CoV-2, and two suggestive clinical features undergo further lab testing (tier 1 lab tests). Tier 1 tests include routine, easily accessible clinical labs such as complete blood count, comprehensive metabolic panel, erythrocyte sedimentation rate (ESR), CRP, and serology/polymerase chain reaction tests for SARS-CoV-2. If tier 1 lab tests results include CRP ≥5 or ESR≥40 and one suggestive lab feature such as neutrophilia or platelet count <150,000μL, the child should undergo tier 2 testing, which includes a more complex lab work up along with an EKG and echocardiogram.

“The purpose of this two-tiered approach is to limit the number of patients who need to undergo a large and expensive diagnostic work up,” said Lauren Henderson, MD, MMSc, an attending rheumatologist at Boston Children's Hospital who heads the ACR’s MIS-C task force. “In children who are very sick (with shock), tier 1 and tier 2 testing should be done in all cases.”