title: Atypical presentations of orbital cellulitis caused by methicillin-resistant Staphylococcus aureus.
abstract: OBJECTIVE
  To evaluate the epidemiologic and clinical features of orbital cellulitis caused by methicillin-resistant Staphylococcus aureus (MRSA).
  
  
  METHODS
  Multicenter, retrospective case series.
  
  
  METHODS
  Fifteen patients with culture-positive MRSA orbital cellulitis.
  
  
  METHODS
  All recent cases of orbital cellulitis at several hospitals and surgical centers were reviewed, and cases with culture-positive MRSA from aspirates were identified. The data collected and analyzed retrospectively included patient demographics, medical history, presenting sign, imaging results, surgical procedure performed, surgical culture results, visual acuity at presentation and last follow-up, and duration of antibiotics.
  
  
  METHODS
  Presenting sign, radiographic evidence of paranasal sinus disease, radiographic evidence of multiple orbital abscesses, presence or absence of antecedent upper respiratory infection, and final visual acuity.
  
  
  RESULTS
  Fifteen cases were identified. The mean patient age was 31.9 years (standard deviation, 24.2 years). Lid swelling was the presenting sign in 14 of 15 patients. No patients had a preceding upper respiratory infection, and only 1 patient had antecedent eyelid trauma. Only 3 of 15 patients had documented adjacent paranasal sinus disease on imaging. Lacrimal gland abscess or dacryoadenitis was the presenting finding in 5 of 15 patients. Multiple orbital abscesses were identified in 4 of 15 patients by computed tomography or magnetic resonance imaging. Fourteen of 15 cases required surgical intervention. Four of 15 cases had loss of visual acuity to light perception or worse. All 4 of these cases had a delay in referral for surgical intervention.
  
  
  CONCLUSIONS
  In these 15 patients with MRSA orbital cellulitis, the typical clinical setting of orbital cellulitis was absent; chiefly, there was no identified antecedent upper respiratory illness, nor was there a preceding traumatic injury. Lid swelling in the absence of recent upper respiratory illness, lacrimal gland focus, multiple orbital abscesses, and lack of adjacent paranasal sinus disease may be predictive factors that suggest MRSA as the causative organism of orbital cellulitis.
  
  
  BACKGROUND
  The author(s) have no proprietary or commercial interest in any materials discussed in this article.
authors.affiliation: Rocky Mountain Lions Eye Institute, University of Colorado, Denver, Colorado, USA.
authors.forename: Marc T
authors.initials: MT
authors.lastname: Mathias
authors.forename: Michael B
authors.initials: MB
authors.lastname: Horsley
authors.forename: Louise A
authors.initials: LA
authors.lastname: Mawn
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Laquis
authors.forename: Kenneth V
authors.initials: KV
authors.lastname: Cahill
authors.forename: Jill
authors.initials: J
authors.lastname: Foster
authors.forename: Malena M
authors.initials: MM
authors.lastname: Amato
authors.forename: Vikram D
authors.initials: VD
authors.lastname: Durairaj
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004487:Edema / Q000175:diagnosis; D015818:Eye Infections, Bacterial / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D005141:Eyelid Diseases / Q000175:diagnosis; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D008875:Middle Aged; D015835:Ocular Motility Disorders / Q000175:diagnosis; D054517:Orbital Cellulitis / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D014057:Tomography, X-Ray Computed; D014792:Visual Acuity; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents