Rapid progression of orbital abscess requiring lateral canthotomy in a pediatric patient.

Subperiosteal abscess (SPA) is a rare complication of acute sinusitis in children that may develop rapidly. In this case report, we describe an 11 year-old boy who presented with a large SPA 2 days after being diagnosed with conjunctivitis. The patient required emergent lateral canthotomy and cantholysis (LCC), IV antibiotics, and emergent surgery. It is crucial that emergency physicians be able to identify and treat this vision-threatening complication.