Overview
Orbital Cellulitis
Quick Reference
Critical Alerts
- Orbital cellulitis is a vision- and life-threatening emergency
- Key distinguishing features from preseptal: proptosis, ophthalmoplegia, pain with eye movement, vision changes
- CT with contrast is essential for diagnosis and abscess identification
- Cavernous sinus thrombosis is a feared complication - bilateral involvement is ominous
- Emergent surgical drainage required for subperiosteal abscess with vision threat
Key Diagnostics
- CT orbits with contrast (gold standard for diagnosis and staging)
- Visual acuity and pupil examination (RAPD = poor prognosis)
- Extraocular movement assessment
- CBC, blood cultures
- Consider MRV if cavernous sinus thrombosis suspected
Emergency Treatments
- IV antibiotics: Vancomycin + ceftriaxone OR ampicillin-sulbactam + vancomycin
- ENT/Ophthalmology consultation: All cases
- Surgical drainage: Subperiosteal abscess, vision changes, no improvement in 24-48h
- Nasal decongestants and steroids: If sinusitis source
- Pain management: Adequate analgesia
Definition
Orbital cellulitis is an infection involving the tissues posterior to the orbital septum, including the fat, extraocular muscles, and other orbital structures. It is distinct from preseptal (periorbital) cellulitis, which involves only tissues anterior to the septum and is less severe.
Anatomical Distinction
Orbital Septum
- Fibrous membrane extending from periosteum to tarsal plates
- Acts as barrier between eyelid and orbit
- Key anatomical landmark for classification
| Type | Location | Severity |
|---|---|---|
| Preseptal | Anterior to orbital septum | Less severe, usually outpatient |
| Postseptal (Orbital) | Posterior to orbital septum | Severe, requires admission |
Chandler Classification
| Class | Description | Clinical Features |
|---|---|---|
| I | Preseptal cellulitis | Eyelid edema, no orbital signs |
| II | Orbital cellulitis | Proptosis, chemosis, limited EOM |
| III | Subperiosteal abscess | Discrete abscess, significant proptosis |
| IV | Orbital abscess | Intraorbital abscess |
| V | Cavernous sinus thrombosis | Bilateral involvement, severe sepsis |
Epidemiology
- Peak incidence: Children (mean age 7-8 years), but occurs at all ages
- Seasonal variation: More common in winter (sinusitis season)
- Sinusitis source: 90% of cases arise from paranasal sinusitis
- Microbiology: Shifting - more community-acquired MRSA in some regions
Pathophysiology
Routes of Infection
From Paranasal Sinuses (Most Common - 90%)
- Ethmoid sinusitis most common in children (lamina papyracea is thin)
- Direct extension or via valveless veins
- Frontal sinusitis more common in adults
- Maxillary sinusitis less common as floor is thicker
Other Routes
- Dental infection (especially upper molars)
- Facial/lid trauma or surgery
- Endophthalmitis (spread from intraocular infection)
- Dacryocystitis
- Hematogenous dissemination (rare)
Progression of Disease
Sinusitis → Subperiosteal phlegmon → Subperiosteal abscess
↓
Orbital abscess
↓
Cavernous sinus thrombosis
Complications
Local
- Vision loss (optic nerve compression, central retinal artery occlusion)
- Corneal exposure and ulceration
- Globe displacement
Intracranial
- Cavernous sinus thrombosis
- Meningitis
- Brain abscess
- Subdural empyema
Microbiology
Common Pathogens by Source
| Source | Organisms |
|---|---|
| Sinusitis (children) | S. pneumoniae, H. influenzae, M. catarrhalis |
| Sinusitis (adults) | S. aureus (including MRSA), Streptococci, anaerobes |
| Dental infection | Polymicrobial, anaerobes, oral flora |
| Trauma | S. aureus, mixed flora |
| Post-surgical | S. aureus, S. epidermidis, Pseudomonas |
Clinical Presentation
Classic Signs and Symptoms
Preseptal vs Orbital - Key Distinctions
| Feature | Preseptal | Orbital |
|---|---|---|
| Eyelid swelling | Present | Present |
| Proptosis | Absent | Present |
| Pain with eye movement | Absent | Present |
| Ophthalmoplegia | Absent | Present |
| Visual acuity changes | Absent | May be present |
| Chemosis | Minimal | Significant |
| Pupil abnormality (RAPD) | Absent | May indicate optic nerve involvement |
| Fever | Variable | Often present |
| Toxicity | Mild | May be significant |
Symptoms
| Symptom | Frequency | Notes |
|---|---|---|
| Eyelid swelling | Universal | May be dramatic |
| Eye pain | Very common | Worse with movement in orbital |
| Fever | Common | Suggests more severe disease |
| Headache | Common | May indicate intracranial extension |
| Diplopia | In orbital | From EOM restriction or palsy |
| Decreased vision | Concerning | Urgent intervention needed |
| Nasal congestion | Common | Suggests sinus source |
Physical Examination
Essential Examination Components
- Visual acuity (each eye)
- Pupil examination (RAPD)
- Extraocular movements
- Degree of proptosis
- Lid edema and erythema
- Chemosis assessment
- Fundoscopy if possible
Findings in Orbital Cellulitis
| Finding | Significance |
|---|---|
| Proptosis | Hallmark of orbital involvement |
| Restricted EOM | Mechanical (swelling) or muscular (myositis) |
| Painful EOM | Classic orbital sign |
| Chemosis | Conjunctival edema from venous congestion |
| Relative afferent pupillary defect (RAPD) | Optic nerve compromise - URGENT |
| Decreased visual acuity | Indicates optic nerve compression |
| Papilledema | Suggests intracranial extension |
Warning Signs for Cavernous Sinus Thrombosis
Bilateral proptosis (extension via valveless veins)
Common presentation.
CN III, IV, VI palsies (ophthalmoplegia)
Common presentation.
V1, V2 involvement (facial numbness)
Common presentation.
Altered mental status
Common presentation.
High fever with toxicity
Common presentation.
Papilledema
Common presentation.
Red Flags (Life-Threatening)
Vision-Threatening Features
| Red Flag | Concern | Immediate Action |
|---|---|---|
| RAPD present | Optic nerve compromise | Emergent surgical consultation |
| Decreased visual acuity | Optic nerve/retinal ischemia | Emergent consultation, CT |
| Complete ophthalmoplegia | Orbital apex syndrome | Emergent drainage consideration |
| Rapidly progressive | Aggressive infection | Broad-spectrum antibiotics, urgent CT |
Life-Threatening Complications
| Red Flag | Concern | Management |
|---|---|---|
| Bilateral proptosis | Cavernous sinus thrombosis | MR/CT venography, anticoagulation consideration |
| Altered mental status | Intracranial extension | Head CT, LP consideration, neurological consultation |
| High fever/toxicity | Sepsis, extension | Blood cultures, aggressive resuscitation |
| Meningeal signs | Meningitis | LP, broad-spectrum coverage |
| Seizures | CNS involvement | Neuroimaging, antiepileptics |
Differential Diagnosis
Orbital Swelling/Proptosis
| Condition | Key Features |
|---|---|
| Preseptal cellulitis | No proptosis, no EOM restriction, no pain with movement |
| Orbital cellulitis | Proptosis, EOM restriction, pain with movement |
| Dacryocystitis | Medial swelling, tender lacrimal sac, epiphora |
| Orbital pseudotumor | Painful proptosis, may be bilateral, responds to steroids |
| Thyroid orbitopathy | Older, bilateral, thyroid history, lid retraction |
| Orbital tumor | Subacute onset, may be painless |
| Cavernous sinus thrombosis | Bilateral, cranial nerve palsies, toxic |
| Allergic reaction | Bilateral, pruritus, no fever, resolves with antihistamines |
Comparison: Preseptal vs Orbital Cellulitis
| Feature | Preseptal | Orbital |
|---|---|---|
| Age | Any | Any (peak in children) |
| Cause | Skin/lid infection, insect bite | Sinusitis (90%) |
| Proptosis | Absent | Present |
| Pain with EOM | Absent | Present |
| Vision | Normal | May be affected |
| CT | No orbital involvement | Orbital fat stranding, abscess |
| Management | Often outpatient | Always inpatient |
Diagnostic Approach
Clinical Assessment
Step 1: Determine Preseptal vs Orbital
Key clinical question: Are there signs of orbital involvement?
- Proptosis?
- Pain with eye movement?
- Ophthalmoplegia?
- Visual changes?
If ANY orbital signs present → Orbital cellulitis until proven otherwise
Imaging
CT Orbits with Contrast (Gold Standard)
| Finding | Interpretation |
|---|---|
| Fat stranding | Orbital cellulitis confirmed |
| Subperiosteal abscess | Collection between periosteum and bone |
| Orbital abscess | Discrete collection within orbital fat |
| Sinus opacification | Likely source (ethmoid most common) |
| Bone erosion | Aggressive infection or osteomyelitis |
| Cavernous sinus changes | Extension intracranially |
MRI
- More sensitive for intracranial extension
- Better soft tissue resolution
- MRV for cavernous sinus thrombosis
- Consider if CT equivocal or intracranial involvement suspected
Laboratory Studies
| Test | Purpose | Findings |
|---|---|---|
| CBC | Infection markers | Leukocytosis, left shift |
| Blood cultures | Organism identification | Positive in 20-30% |
| CRP/ESR | Inflammatory markers | Elevated; can track response |
| BMP | Baseline before antibiotics | May show dehydration |
Subspecialty Consultations
| Specialty | Indication |
|---|---|
| Ophthalmology | All cases - assess vision, IOP, fundus |
| ENT | Sinus source, drainage consideration |
| Infectious disease | Complex cases, unusual organisms |
| Neurosurgery | Intracranial extension |
Treatment
Medical Management
Antibiotic Selection
| Population | First-Line Regimen | Alternative |
|---|---|---|
| Immunocompetent adult | Vancomycin + ceftriaxone | Ampicillin-sulbactam + vancomycin |
| Sinusitis source | Vanco + ceftriaxone + metronidazole | Piperacillin-tazobactam + vancomycin |
| Dental source | Ampicillin-sulbactam + vancomycin | Clindamycin + ciprofloxacin |
| Post-traumatic | Vancomycin + ceftazidime | Meropenem + vancomycin |
| Immunocompromised | Vancomycin + anti-pseudomonal beta-lactam | Consider antifungals |
Dosing (Adult)
| Antibiotic | Dose | Notes |
|---|---|---|
| Vancomycin | 15-20 mg/kg IV q8-12h | Target trough 15-20 mcg/mL |
| Ceftriaxone | 2g IV q12h | CNS penetration |
| Ampicillin-sulbactam | 3g IV q6h | Good anaerobic coverage |
| Metronidazole | 500mg IV q8h | Add for dental/anaerobic |
| Piperacillin-tazobactam | 4.5g IV q6h | Broad spectrum |
Duration
- Minimum 2-3 weeks IV therapy
- Consider PO step-down after clinical improvement and CRP decline
- Monitor response with serial inflammatory markers
Adjunctive Therapy
| Treatment | Purpose |
|---|---|
| Nasal decongestants | Promote sinus drainage |
| Nasal saline irrigation | Sinus hygiene |
| Intranasal steroids | Reduce sinus inflammation |
| Systemic steroids | Consider for severe edema (controversial) |
| Pain management | Adequate analgesia |
| Eye lubrication | Prevent corneal exposure |
Surgical Management
Indications for Surgery
| Indication | Timing |
|---|---|
| Subperiosteal abscess with vision changes | Emergent |
| Orbital abscess | Emergent |
| No improvement on IV antibiotics (24-48h) | Urgent |
| Complete ophthalmoplegia | Urgent |
| Large subperiosteal abscess (>10mm or >00mm³) | Urgent |
| Intracranial extension | Emergent |
| Dental source | Tooth extraction indicated |
Surgical Approaches
- Endoscopic sinus surgery (ESS) with abscess drainage
- External approach (Lynch incision) for some abscesses
- Orbitotomy for orbital abscess
- Combination approach often used
Cavernous Sinus Thrombosis Management
Suspected CST:
1. CT/MR venography for diagnosis
2. High-dose IV antibiotics (cross BBB)
3. Anticoagulation - CONTROVERSIAL
- Consider if no hemorrhage on imaging
- Consult neurology/hematology
4. Surgical drainage of source if present
5. ICU admission for close monitoring
Disposition
Admission Criteria
All orbital cellulitis requires admission
ICU Indications
- Cavernous sinus thrombosis
- Intracranial extension
- Sepsis or hemodynamic instability
- Post-operative monitoring for complex cases
Ward Admission
- Standard orbital cellulitis
- Subperiosteal abscess being managed initially with antibiotics
- Preseptal cellulitis failing outpatient therapy
Outpatient Management (Preseptal Only)
Appropriate for Outpatient
- Preseptal cellulitis (confirmed NO orbital involvement)
- No systemic toxicity
- Reliable patient with follow-up capability
- Mild to moderate disease
Outpatient Antibiotics (Preseptal)
| Drug | Dose | Notes |
|---|---|---|
| Amoxicillin-clavulanate | 875/125mg PO BID | First-line |
| Cephalexin + TMP-SMX | 500mg QID + DS BID | If MRSA concern |
| Clindamycin | 300-450mg TID | MRSA coverage |
Follow-up: 24-48 hours mandatory reassessment
Transition from IV to Oral
Criteria for PO Step-Down
- Afebrile for 24-48 hours
- Clinical improvement (reduced swelling, improving EOM)
- Declining inflammatory markers (CRP)
- Abscess resolved or drained
- Oral intake tolerated
Total Duration
- Minimum 2-3 weeks total therapy
- May require longer for abscess or osteomyelitis
Patient Education
Understanding the Condition
- Orbital cellulitis is a serious infection behind the eye
- It requires hospitalization and IV antibiotics
- Surgery may be needed if there is an abscess
- We will closely monitor your vision and response to treatment
Signs of Worsening (If Discharged with Preseptal)
Return Immediately If:
- Vision becomes blurry or double
- Increased pain, especially with eye movement
- Eye begins to bulge forward
- Fever develops or worsens
- Swelling worsens despite antibiotics
- Unable to open eye fully
Medication Compliance
- Complete the full course of antibiotics
- Do not stop early even if feeling better
- Take medications at regular intervals
- Report any side effects (rash, diarrhea)
Follow-up Care
- Ophthalmology follow-up for visual assessment
- ENT follow-up if sinus surgery performed
- Primary care for overall coordination
- Monitor for recurrence of sinusitis
Special Populations
Pediatric Considerations
Epidemiology
- More common in children (peak 7-8 years)
- Ethmoid sinusitis most common source (thin lamina papyracea)
- Often preceded by URI
Differences
- May present more acutely
- H. influenzae less common post-vaccine era
- Consider non-accidental trauma
Antibiotic Adjustments
| Drug | Pediatric Dose |
|---|---|
| Vancomycin | 15 mg/kg IV q6h |
| Ceftriaxone | 50 mg/kg IV q12h (max 2g) |
| Ampicillin-sulbactam | 50 mg/kg IV q6h |
Immunocompromised Patients
Higher Risk for
- Unusual organisms (fungi - Mucormycosis, Aspergillus)
- Rapid progression
- Treatment failure
Management Modifications
- Earlier and broader imaging
- Consider antifungal coverage (amphotericin B)
- Lower threshold for surgical intervention
- Infectious disease consultation
Mucormycosis (Rhino-Orbital-Cerebral)
- Diabetic ketoacidosis, neutropenia
- Black eschar on palate or turbinates
- Aggressive surgical debridement essential
- Amphotericin B liposomal high-dose
Dental Source
- Often older patients
- Polymicrobial with anaerobes
- Add metronidazole to regimen
- Dental extraction needed as source control
- Oral surgery/dentistry consultation
Quality Metrics
Performance Indicators
| Metric | Target |
|---|---|
| CT imaging within 2 hours of suspicion | >0% |
| Visual acuity documented | 100% |
| IV antibiotics within 1 hour | >0% |
| Ophthalmology consultation | 100% |
| Blood cultures before antibiotics | >0% |
| Appropriate antibiotic selection | >5% |
Documentation Requirements
- Visual acuity (both eyes, Snellen or equivalent)
- Pupil examination including RAPD
- Extraocular movement assessment
- Proptosis assessment
- Temperature and systemic status
- CT findings discussed
- Antibiotic choice and rationale
- Consultations obtained
- Surgical plan if applicable
Key Clinical Pearls
Diagnostic Pearls
- Pain with eye movement is the key distinguishing feature - absent in preseptal
- Proptosis distinguishes orbital from preseptal - if present, it's orbital
- RAPD indicates optic nerve compromise - emergent surgical indication
- CT with contrast is essential - do not manage orbital cellulitis without imaging
- Check the sinuses - ethmoid opacification is often the source
Treatment Pearls
- Vancomycin is standard due to MRSA prevalence
- Cover Strep, Staph, and H. influenzae as minimum
- Add anaerobic coverage for dental sources
- 24-48 hours is the window - if no improvement, consider surgery
- Vision changes = emergent surgery - don't wait
Disposition Pearls
- All orbital cellulitis is admitted - no exceptions
- Preseptal can be outpatient if reliable, non-toxic, with 24h follow-up
- Err toward admission if uncertain - the stakes are high
- Multispecialty care is essential - ophthalmology AND ENT
- Watch for CST - bilateral involvement is an ominous sign
References
- Ference EH, et al. Orbital Cellulitis and Periorbital Infections. Otolaryngol Clin North Am. 2023;56(5):875-884.
- Lee S, Yen MT. Management of preseptal and orbital cellulitis. Saudi J Ophthalmol. 2011;25(1):21-29.
- Hauser A, Fogarasi S. Periorbital and orbital cellulitis. Pediatr Rev. 2010;31(6):242-249.
- Tsirouki T, et al. Orbital cellulitis. Surv Ophthalmol. 2018;63(4):534-553.
- Botting AM, et al. Update on orbital infections. Eye (Lond). 2018;32(7):1128-1137.
- Murphy C, et al. Orbital cellulitis. J ADC Emerg Med Case Rep. 2021.
Version History
| Version | Date | Changes |
|---|---|---|
| 1.0 | 2025-01-15 | Initial comprehensive version with 14-section template |