New Cluster of Acute Flaccid Myelitis in Western Pennsylvania.

Acute flaccid myelitis is a debilitating illness characterized by acute onset of limb weakness, with one or more spinal segments displaying magnetic resonance imaging-confirmed gray matter lesions. Since the first outbreak in 2014, tracking by the Centers for Disease Control and Prevention has demonstrated biennial epidemics in the United States, with a current outbreak occurring in 2018. The cases of 3 children with acute flaccid myelitis who were initially thought to have common nonneurologic diagnoses are presented. Emergency physicians need to be vigilant to recognize the subtleties of acute flaccid myelitis because the illness progression is rapid and therapy is nuanced.