Natural history
The natural history of each case of orbital cellulitis varies based on the etiology, microbiology and immune status, e.g., course of MRSA orbital cellulitis from a skin source differs from sinusitis-related MRSA orbital cellulitis.
General considerations
Orbital cellulitis is an end organ–threatening condition and a potentially fatal illness.
With initial diagnosis, hospital admission with treatment and close observation is preferred over clinic-based management.
Consider infectious disease (ID) and ear, nose, and throat (ENT) consultation and comanagement.
Medical therapy
Normal defenses
- Hypervirulent organism, e.g., MRSA
- Clinical practice guidelines have been developed for skin and soft-tissue infections, bacteremia and endocarditis, pneumonia, bone and joint infections, and CNS infections (Stevens, Clin Infect Dis 2014).
- Recommendations do not directly involve orbital cellulitis.
- Most common initial IV antibiotics choice: Clindamycin/Vancomycin; consider dual therapy with third-generation cephalosporin.
- Consider ID consult.
Compromised defenses
- Sinusitis-related orbital cellulitis — primary cause of orbital cellulitis
- Children < 9 years old: typically single pathogen aerobic infections (Streptococcus and Staphylococcus strains)
- Children 9–15 years old: increasing prevalence of polymicrobial disease
- Adults: polymicrobial infections (+/- anaerobes)
- Dual therapy IV antibiotics: either amoxicillin-sulbactam or a third-generation cephalosporin (cover most aerobes and anaerobes) plus either clindamycin/vancomycin (MRSA coverage)
- Twice daily oxymetazoline nasal spray
- Expectant management:
- Careful monitoring for an afferent pupillary defect, at least as often as every 2 hours (nursing) and every 8 hours (house staff)
- Default to surgery if
- An APD develops at any time
- Failure to defervesce after 36 hours of appropriate ABX
- Clinical deterioration despite 48 hours treatment
- No improvement after 72 hours
- Systemic corticosteroids do not seem to alter the outcome in pediatric orbital cellulitis with subperiosteal abscess adequately treated with antibiotics, although their use correlated with decreased requirement for post-discharge antibiotics (Yen OPRS 2005).
- The mean and median duration of IV antibiotics in a cohort of 42 patients with nonsurgical subperiosteal abscess management was 4 days (range 2–8 days) with post-discharge oral antibiotic treatment for 2 to 3 weeks (Emmett Hurley OPRS 2012).
- Breach/bypass of normal orbital barriers: either amoxicillin-sulbactam or a third-generation cephalosporin cover most aerobes and anaerobes +/- MRSA coverage
- Primary or secondary systemic immunodeficiency/immunocompromised state
- Either amoxicillin-sulbactam or a third-generation cephalosporin cover most aerobes and anaerobes +/- MRSA coverage
- Correct underlying immunodeficiency if possible, e.g., diabetic ketoacidosis
- Strongly consider ID consult
Surgery
Normal defenses
- Hypervirulent organism, e.g., MRSA
- Surgical debridement necrotic tissue should be considered (Figure 2)


Figure 2. A. Immediate postoperative photo following debridement of necrotic tissue from MRSA skin wound. No closure was performed. B. 6-month result.
Compromised defenses
- Sinusitis-related orbital cellulitis (#1 cause of orbital cellulitis)
- Subperiosteal abscess (SPA) can develop adjacent to infected sinus and is typically an extension of sinus infection through orbital wall causing subperiosteal orbital purulence without generalized orbital involvement
- SPA management (Liao, Ophthalmology 2015)
- Emergent drainage: patients of any age whose optic nerve or retinal function is compromised by the mass effect of an abscess
- Urgent drainage within 24 hours
- Large SPA
- SPAs that extend superiorly or inferiorly beyond the medial subperiosteal space
- Frontal sinus involvement
- Intracranial extension
- Presumed anaerobic infection
- Patients ≥ 9 years of age (risk for anaerobic infection)
- The emergence of aggressive aerobic pathogens, e.g. MRSA, in the context of sinusitis-related disease does not lead to modification of the above treatment algorithm
- In the setting of SPA > 2 cm with concurrent sinusitis, combined sinus drainage surgery and subperiosteal drainage has been associated with improved treatment outcome versus SPA drainage alone (Dewan, OPRS 2011)
Breach/bypass of normal orbital barriers
The sinusitis-related SPA protocol is not directly applicable to other forms of SPA, although general principals might be useful, e.g., careful monitoring for APD, failed improvement prompting surgical drainage.
Primary or secondary systemic immunodeficiency/immunocompromised state
The sinusitis-related SPA protocol is not directly applicable to other forms of SPA, although general principals might be useful, e.g., careful monitoring for APD, failed improvement prompting surgical drainage.
Common antibiotics
- Ampicillin/sulbactam (Unasyn)
- Sulbactam = beta-lactamase inhibitor
- Covers Staph, Strep, anaerobes and Enterobacteriaceae
- Does not cover pseudomonas or MRSA
- Piperacillin/tazobactam (Zosyn)
- Tazobactam = beta-lactamase inhibitor
- Spectrum similar to Unasyn, covers pseudomonas
- Does not cover MRSA
- Third-generation cephalosporin (Cefotaxime, ceftriaxone, ceftazidime)
- Covers Staph, Strep, and Enterobacteriaceae
- Does not cover anaerobes, pseudomonas, or MRSA
- MRSA coverage if suspected