Orbital Cellulitis

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)

Characterized by

• Fever

• Proptosis

• Restriction of extraocular movements

• Swelling with redness of the lids

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 of 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

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 beta-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