Approach to managing orbital (postseptal) cellulitis

Orbital (postseptal) cellulitis is an emergency; it can lead to orbital abscesses, extension of infection through the superior ophthalmic vein causing cavernous sinus thrombosis, intracranial infection and vision loss.

Admit patients with suspected orbital cellulitis to hospital and:

• perform computed tomography (CT) of the orbits and sinuses
• collect blood samples for culture
• perform 4-hourly eye observations (visual acuity and pupil reaction).

Urgent surgical drainage of the sinuses or of an orbital, subperiosteal or intracranial abscess may be required to prevent loss of vision. If there is intracranial extension, consider brain abscess, which requires empirical antibiotic therapy with activity against anaerobes.

For patients with orbital cellulitis who have sepsis or septic shock, start antibiotic therapy within 1 hour of presentation to medical care or, for ward-based patients, development of sepsis or septic shock. Antibiotics should be administered immediately after blood samples are taken for culture. For nonantibiotic management of sepsis or septic shock, see Resuscitation of patients with sepsis or septic shock.

Pathogens causing orbital cellulitis include Staphylococcus aureus, Streptococcus species, Haemophilus influenzae type b (Hib) (in patients who are not fully vaccinated) and anaerobic bacteria. Orbital cellulitis can be caused by fungi in patients with immune compromise or diabetes.

In confirmed cases of Hib infection, clearance antibiotics with or without immunisation may be required for the patient and close contacts; see Clearance antibiotics for invasive meningococcal or Hib disease.

Patients with orbital cellulitis are rarely suitable for ambulatory antimicrobial therapy. Use intravenous therapy initially, then switch to oral therapy when the infection is improving (see Guidance for intravenous to oral switch and Modification and duration of therapy for orbital (postseptal) cellulitis).