title: Subperiosteal orbital hemorrhage as initial manifestation of Christmas disease (factor IX deficiency).
abstract: OBJECTIVE
  To report a case of subperiosteal orbital and subgaleal hemorrhage with optic nerve compromise in a patient with a factor IX deficiency.
  
  
  METHODS
  Interventional case report.
  
  
  METHODS
  A 5-year-old male presented 10 days after mild trauma with progressive left-sided scalp swelling, proptosis, and visual loss.
  
  
  RESULTS
  The patient had marked proptosis of the left eye, 20/200 visual acuity, and an afferent pupillary defect. Magnetic resonance imaging demonstrated a large subgaleal and left subperiosteal orbital hematoma. Quantitative assays of coagulation proteins identified a factor IX deficiency (Christmas disease).
  
  
  CONCLUSIONS
  Delayed-onset subgaleal and subperiosteal orbital hematoma can rarely be an initial manifestation of Christmas disease.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Medhat F
authors.initials: MF
authors.lastname: Guirgis
authors.forename: William A
authors.initials: WA
authors.lastname: Segal
authors.forename: Gregg T
authors.initials: GT
authors.lastname: Lueder
mesh_terms: D002675:Child, Preschool; D019299:Decompression, Surgical; D005164:Factor IX / Q000627:therapeutic use; D006406:Hematoma / Q000175:diagnosis* / Q000601:surgery; D002836:Hemophilia B / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D019315:Retrobulbar Hemorrhage / Q000175:diagnosis* / Q000601:surgery
chemical_list: D005164:Factor IX