Don't Forget the Flu - Determining the Etiology of Infective Myositis in a Child: A Case Report

Infective myositis is an acute, self-limited condition, rarely occurring in children with recent viral infections. The condition is often overlooked by emergency physicians when endeavoring to exclude other diagnoses included in the differential. Diagnosis of the condition can be difficult when based purely on clinical presentation because it shares symptoms with much more concerning neurological illnesses. A few simple laboratory tests are indicated to reach the correct diagnosis. The following case report describes a three-year-old female diagnosed with a recent upper respiratory tract infection presenting to the emergency department with complaints of fatigue and inability to walk. She was diagnosed with an influenza-like illness three days prior by her pediatrician, the symptoms of which had mostly resolved by the time of presentation. Muscle weakness and abnormal, uncoordinated gait with an acute upper respiratory tract infection in a child may be cause for concern, prompting unnecessary work-up. Emergency physicians should be aware of the signs and symptoms of influenza-associated infective myositis in children, especially during influenza season.