Orbital Cellulitis

Key Features

• Infection of the paranasal sinuses is the usual underlying cause

• Examples of infecting organisms include

  • Streptococcus pneumoniae

  • Other streptococci

  • Haemophilus influenzae

  • Staphylococcus aureus, including methicillin-resistant S aureus (MRSA) (less commonly)

Clinical Findings

• Characterized by

  • Fever

  • Proptosis

  • Restriction of extraocular movements

  • Swelling with redness of the lids

Diagnosis

• Diagnosis usually made on clinical grounds alone

• Leukocytosis and an increased sedimentation rate are almost invariably present but are not specific

• Blood cultures may be positive

• Noncontrast coronal CT scans provide a rapid and effective means to assess all the paranasal sinuses, to identify areas of greater concern (such as bony dehiscence, periosteal elevation or maxillary tooth root exposure within the sinus), and to direct therapy

Treatment

• Immediate treatment with intravenous antibiotics is necessary to prevent optic nerve damage and spread of infection to the cavernous sinuses, meninges, and brain

• Penicillinase-resistant penicillin, such as nafcillin, is recommended, possibly together with metronidazole or clindamycin to treat anaerobic infections

• If trauma is the underlying cause, cefazolin or ceftriaxone should be added to ensure coverage for S aureus and group A β-hemolytic streptococci

• Vancomycin or clindamycin may be required if MRSA is a concern

• For patients with penicillin hypersensitivity, vancomycin, levofloxacin, and metronidazole are recommended

• The response to antibiotics is usually excellent, but surgery may be required to drain the paranasal sinuses or orbital abscess