EENT · PANCE / PANRE

Orbital Cellulitis vs Preseptal (Periorbital) Cellulitis

Lid swelling alone (preseptal) vs proptosis, ophthalmoplegia, pain on EOM (orbital); CT and IV antibiotics if any orbital sign.

Also known as: orbital cellulitis, preseptal cellulitis, periorbital cellulitis, post-septal cellulitis

Overview

Preseptal (periorbital) cellulitis is infection of the eyelid and surrounding skin ANTERIOR to the orbital septum. Orbital cellulitis is infection of the soft tissues POSTERIOR to the septum, involving orbital fat and possibly extraocular muscles, with risk of visual and intracranial complications.

Epidemiology

Both are more common in children. Orbital cellulitis classically follows acute bacterial sinusitis (especially ethmoid) in 60-80% of pediatric cases. Preseptal cellulitis often follows local skin trauma, hordeolum, dacryocystitis, or insect bite. Streptococcus pneumoniae, Staphylococcus aureus (including MRSA), Streptococcus pyogenes, and Haemophilus influenzae (less common since vaccination) are typical; anaerobes and polymicrobial infection are more common in older children and adults, and in postoperative orbital infection.

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Risk factors

Acute or chronic sinusitis (especially ethmoid sinusitis in children)
Recent upper respiratory infection
Local trauma, insect bite, eyelid laceration
Hordeolum, blepharitis, dacryocystitis, conjunctivitis
Recent orbital or sinus surgery
Immunocompromise, diabetes (risk for invasive fungal disease in orbital cellulitis — mucormycosis)
Age younger than 5 (Haemophilus influenzae historically; now less common)

Pathophysiology

Preseptal infection arises from contiguous skin or adnexal sources and is contained anterior to the orbital septum, the fibrous extension of the periosteum into the lids. Orbital cellulitis usually arises by direct extension from the ethmoid sinus through the thin lamina papyracea, or from septic embolization via the valveless ophthalmic veins. Infection in the orbital fat can progress to subperiosteal abscess (most often along the medial wall), orbital abscess, and intracranial extension (cavernous sinus thrombosis, meningitis, brain abscess).

Clinical presentation

Symptoms

Preseptal: eyelid swelling, redness, warmth, tenderness; usually well-appearing; no vision loss, no double vision, no pain with eye movement
Orbital: same eyelid signs PLUS pain with eye movement, double vision, decreased vision, fever, malaise, headache
Recent sinusitis, URI, trauma, or facial infection

Signs / physical exam

Preseptal: lid edema and erythema, NO proptosis, full and painless extraocular motility, normal acuity, normal pupil
Orbital: proptosis, restricted and painful extraocular motility, decreased visual acuity, RAPD, chemosis, elevated IOP
Decreased color vision and RAPD suggest optic nerve compromise — emergency
Fever, leukocytosis more common in orbital disease
Always examine the nose and sinuses; tenderness over maxillary/ethmoid sinuses

Classic findings

Lid swelling with painless full EOM and intact vision (preseptal) versus lid swelling plus proptosis, painful EOM, and decreased vision (orbital).

Differential diagnosis

Allergic eyelid swelling — Bilateral, itchy, no fever, no tenderness, no warmth; responds to antihistamines
Insect bite or contact dermatitis — Pruritus, recent exposure, no systemic signs; mild or no warmth
Thyroid eye disease — Proptosis, lid retraction (not edema), restricted EOM, hyperthyroid features; subacute or chronic
Orbital pseudotumor (idiopathic orbital inflammation) — Painful proptosis, EOM restriction, often responsive to steroids; imaging shows enhancing inflammatory mass
Orbital tumor or metastasis — Subacute progressive proptosis without infection signs; imaging diagnostic
Cavernous sinus thrombosis — Bilateral chemosis, proptosis, ophthalmoplegia, cranial nerve V1/V2 involvement; severe headache, fever — late complication of orbital cellulitis
Invasive fungal sinusitis (mucormycosis, aspergillosis) — Diabetic ketoacidosis or immunocompromised patient with black nasal/palatal eschar; rapidly progressive; surgical emergency
Necrotizing fasciitis of the periorbital area — Rapid spread, bullae, dusky skin, systemic toxicity; surgical emergency

Diagnostic workup

Diagnostic criteria

Clinical diagnosis based on examination findings. Chandler classification stages orbital disease: I preseptal, II orbital cellulitis without abscess, III subperiosteal abscess, IV orbital abscess, V cavernous sinus thrombosis.

Labs

CBC with differential, CRP, blood cultures (especially in moderate/severe disease)
Cultures from any drained pus, conjunctival swab, sinus aspirate at the time of surgical intervention
Glucose, electrolytes if mucormycosis is being considered (diabetic ketoacidosis)

Imaging

Contrast-enhanced CT of the orbits AND sinuses with thin (2 mm) axial and coronal cuts — primary imaging for any suspicion of orbital involvement (proptosis, pain on EOM, restricted EOM, decreased vision, no improvement on oral antibiotics in 24-48 h, age <1, or unreliable exam)
MRI orbits with contrast if intracranial extension or cavernous sinus thrombosis is suspected, or for better soft tissue detail
Avoid LP unless meningitis is suspected and after imaging excludes mass effect

Diagnostic algorithm

Feature	Preseptal cellulitis	Orbital cellulitis
Anatomy	Anterior to orbital septum	Posterior to orbital septum
Source	Skin, lid, lacrimal	Sinusitis (ethmoid), trauma, postop
Visual acuity	Normal	May be decreased; RAPD if optic nerve compromise
Eye movement	Full, painless	Restricted, painful
Proptosis	Absent	Present
Chemosis	Minimal	Marked
Fever / toxicity	Mild or absent	Often present
Imaging	Usually clinical; CT if uncertain	CT orbits + sinuses with contrast
Antibiotics	Oral if mild + reliable follow-up; IV if young/sick	IV vancomycin + ceftriaxone (± metronidazole)
Surgery	Rarely needed	Subperiosteal/orbital abscess drainage; sinus drainage

Bedside differentiation of preseptal vs orbital cellulitis.

Treatment

First-line

Mild preseptal cellulitis (well-appearing, low-risk patient): OUTPATIENT oral antibiotics covering S. aureus (including MRSA in many areas) and streptococci — amoxicillin-clavulanate plus trimethoprim-sulfamethoxazole or clindamycin; close follow-up in 24-48 h
Moderate to severe preseptal, all children younger than 1 year, unreliable follow-up, or any inability to exclude orbital extension: ADMIT for IV antibiotics — ampicillin-sulbactam OR ceftriaxone PLUS vancomycin (or clindamycin) for MRSA coverage
Orbital cellulitis: HOSPITALIZE with IV antibiotics — vancomycin PLUS ceftriaxone or ampicillin-sulbactam; add metronidazole for anaerobic coverage in older children/adults or chronic sinusitis; duration usually 2-4 weeks total (IV transitioning to oral as appropriate)
Saline nasal irrigation and topical/oral decongestants for sinusitis component
Consult ophthalmology AND otolaryngology for any orbital cellulitis

Complications

Subperiosteal abscess
Orbital abscess
Optic neuropathy and permanent vision loss (compressive, ischemic, or inflammatory)
Central retinal artery or vein occlusion
Cavernous sinus thrombosis (bilateral involvement, cranial neuropathies, septic embolism)
Meningitis, epidural or subdural empyema, brain abscess
Septicemia
Mucormycosis or invasive aspergillosis in immunocompromised — life-threatening

PANCE pearls

Pain with eye movement, restricted EOM, proptosis, or decreased vision means orbital cellulitis until proven otherwise — image and admit.
Preseptal cellulitis has NORMAL EOM, NORMAL vision, and NO proptosis — clinical distinction from orbital is essential.
Always obtain CT orbits and sinuses with contrast when orbital involvement is suspected.
Empiric coverage for MRSA is now standard given high community prevalence.
Diabetic or immunocompromised patient with rapidly progressive orbital signs and black nasal eschar — think mucormycosis and call ENT/IDS emergently.
Medial subperiosteal abscess from ethmoid sinusitis is the most common operative finding in pediatric orbital cellulitis.

References

AAO PPP — American Academy of Ophthalmology Preferred Practice Pattern: Orbital infections (see Oculofacial Plastics PPP)
IDSA — Infectious Diseases Society of America guidelines for the diagnosis and management of acute bacterial rhinosinusitis (relevant for orbital extension)
AAO-HNS — American Academy of Otolaryngology-Head and Neck Surgery clinical practice guidelines on sinusitis and complications

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