Overview
Definition:
Periorbital cellulitis, also known as preseptal cellulitis, is an infection of the eyelids and tissues anterior to the orbital septum
Orbital cellulitis is a more severe infection involving the orbital tissues posterior to the orbital septum, including the muscles, fat, and optic nerve.
Epidemiology:
Periorbital cellulitis is significantly more common in children than orbital cellulitis, with a male predominance
Common causes include trauma, insect bites, and secondary spread from local infections like sinusitis, dacryocystitis, or conjunctivitis
Orbital cellulitis is less common but carries a higher risk of vision-threatening complications.
Clinical Significance:
Distinguishing between periorbital and orbital cellulitis is crucial due to the vastly different management strategies and potential for severe morbidity, including vision loss, meningitis, and brain abscess, associated with orbital cellulitis
Prompt and accurate diagnosis through clinical assessment and imaging is vital for optimal patient outcomes.
Clinical Presentation
Symptoms:
Periorbital cellulitis: Eyelid swelling, erythema, warmth, tenderness
Absence of proptosis, ophthalmoplegia, or visual changes
Orbital cellulitis: Symptoms of periorbital cellulitis plus: Pain with eye movements
Proptosis (bulging of the eyeball)
Ophthalmoplegia (restricted eye movements)
Decreased visual acuity
Diplopia
Fever and malaise may be more pronounced.
Signs:
Periorbital cellulitis: Erythema and edema confined to the eyelids
conjunctiva may be injected but chemosis is absent
Normal extraocular movements and globe position
Normal vision
Orbital cellulitis: Marked eyelid swelling and erythema
Proptosis
Limitation of eye movements in multiple directions
Ptosis
Afferent pupillary defect in severe cases
Decreased visual acuity
Chemosis (conjunctival edema)
Signs of systemic illness may be present.
Diagnostic Criteria:
Diagnosis is primarily clinical
The key differentiating feature is the presence of symptoms and signs posterior to the orbital septum
Clinical guidelines emphasize the importance of assessing for proptosis, ophthalmoplegia, pain with eye movements, and visual acuity changes to differentiate orbital from periorbital cellulitis.
Diagnostic Approach
History Taking:
Inquire about recent trauma, insect bites, upper respiratory infections, sinusitis, or otitis media
Ask about the onset and progression of symptoms, fever, visual disturbances (blurring, double vision), pain with eye movements, and any prior episodes
Document vaccination status (e.g., for H
influenzae type b).
Physical Examination:
Perform a thorough examination, including vital signs
Assess eyelid edema and erythema
Carefully evaluate for proptosis using a ruler or exophthalmometer
Test extraocular movements in all gazes, noting pain or restriction
Assess visual acuity using age-appropriate charts
Check for afferent pupillary defects
Examine the conjunctiva for chemosis
Palpate for sinus tenderness.
Investigations:
Periorbital cellulitis: Typically does not require imaging unless there is suspicion of underlying sinusitis or complication
Orbital cellulitis: Imaging is mandatory
CT scan of the orbits with intravenous contrast is the modality of choice for initial assessment, demonstrating soft tissue swelling, orbital fat stranding, abscess formation, and sinus involvement
MRI can provide better soft tissue detail and is useful for assessing intracranial extension
Blood cultures and CBC are indicated for orbital cellulitis.
Differential Diagnosis:
Periorbital cellulitis: Allergic reactions, insect bites, chalazion, stye (hordeolum), dacryocystitis, pre-orbital edema from other causes
Orbital cellulitis: Periorbital cellulitis, orbital pseudotumor, rhabdomyosarcoma, thyroid eye disease, orbital foreign body, orbital abscess, cavernous sinus thrombosis.
Management
Initial Management:
Periorbital cellulitis: Outpatient management is often appropriate for mild cases
Close follow-up is essential
Orbital cellulitis: Requires hospitalization and aggressive management
Intravenous antibiotics are initiated promptly after cultures are obtained
Consult ophthalmology and ENT services.
Medical Management:
Periorbital cellulitis: Oral antibiotics targeting common pathogens (Staphylococcus aureus and Streptococcus pyogenes)
Options include amoxicillin-clavulanate, cephalexin, or clindamycin
Duration of therapy is typically 7-10 days
Orbital cellulitis: Intravenous antibiotics covering Gram-positive, Gram-negative, and anaerobic organisms
Empiric regimens often include a beta-lactam/beta-lactamase inhibitor (e.g., ampicillin-sulbactam, piperacillin-tazobactam) or a third-generation cephalosporin (e.g., ceftriaxone, cefotaxime) plus clindamycin or metronidazole
Doses are weight-based for pediatric patients
Antibiotic choice should consider local resistance patterns and penetration into orbital tissues.
Surgical Management:
Indications for surgery in orbital cellulitis include the presence of a drainable orbital abscess (visualized on CT/MRI), failure to improve with IV antibiotics, or suspicion of sinusitis requiring sinusotomy
Surgical drainage may be performed via anterior orbitotomy or endoscopic sinus surgery.
Supportive Care:
Provide symptomatic relief with analgesics and antipyretics
Monitor vital signs closely
Ensure adequate hydration and nutrition
Eye care may include warm compresses for periorbital cellulitis
For orbital cellulitis, close monitoring of visual acuity, pupillary response, and extraocular movements is critical.
Complications
Early Complications:
Orbital cellulitis: Vision loss (secondary to optic nerve compromise, retinal artery occlusion), intracranial extension (meningitis, brain abscess), cavernous sinus thrombosis, orbital abscess rupture into globe, sepsis.
Late Complications:
Strabismus, orbital scarring, eyelid deformities, vision impairment, recurrent infections.
Prevention Strategies:
Prompt treatment of underlying sinonasal infections, careful management of periorbital trauma to prevent skin breakdown, and early recognition and aggressive management of orbital cellulitis can prevent serious complications.
Prognosis
Factors Affecting Prognosis:
Timeliness of diagnosis and initiation of appropriate therapy are paramount
The presence of proptosis, ophthalmoplegia, visual changes, and associated intracranial extension are poor prognostic indicators
Age and underlying immunocompromise can also affect outcomes.
Outcomes:
With prompt and appropriate treatment, periorbital cellulitis typically resolves completely without sequelae
Orbital cellulitis, when managed aggressively and without significant delay, often has a good prognosis for visual recovery
However, some patients may experience permanent vision deficits or residual strabismus.
Follow Up:
Patients with periorbital cellulitis require close follow-up within 24-48 hours to ensure resolution
Patients hospitalized with orbital cellulitis will have prolonged monitoring and follow-up for several weeks to months to assess for complications and ensure complete recovery
ophthalmology and ENT follow-up are typically required.
Key Points
Exam Focus:
The key differentiating factor between periorbital and orbital cellulitis is the presence of signs posterior to the orbital septum (proptosis, ophthalmoplegia, pain with EOM, vision changes)
CT scan is the investigation of choice for suspected orbital cellulitis
Orbital cellulitis is a medical emergency requiring prompt IV antibiotics and potential surgical intervention.
Clinical Pearls:
Always assess visual acuity and extraocular movements in any child with eyelid swelling and erythema
A thorough examination for sinonasal symptoms is crucial as sinusitis is a common predisposing factor for orbital cellulitis
Remember that even a seemingly minor eyelid abrasion can serve as an entry point for infection.
Common Mistakes:
Mistaking orbital cellulitis for periorbital cellulitis, leading to delayed aggressive management
Inadequate antibiotic coverage for orbital cellulitis, failing to include agents effective against Gram-negative bacteria or anaerobes
Delaying imaging in suspected orbital cellulitis
Discharging patients with orbital cellulitis without close follow-up or ophthalmology consultation.