Abstract
We report a case of a nine-year-old boy with facial orbital subperiosteal abscess (SPA) arising from antecedent lacrimal sac infection. The patient presented at our hospital with high fever, swelling from right eyelid to cheek, and proptosis. A previous hospital had performed antibiotic therapy as initial treatment for a few days, and it was unsuccessful. The patient was initially diagnosed with severe infection of the orbit and face as a complication of sinusitis, because of his physical status and SPA and sinusitis documented on CT scan. On the same day, he underwent emergency surgical drainage by external incision. Pus was evacuated, and the abscess was recognized as not directly related with sinusitis, but induced from lacrimal sac infection. Streptococcus constellatus and Prevotella intermedia were isolated from the drained pus. He healed without serious sequela such as visual disorder. We conclude that early surgical intervention is required in cases with orbital SPA or orbital abscess that were unresponsive to antibiotic therapy or that manifest signs of serious complications such as proptosis, decline of visual acuity, disturbance of consciousness, and so on.