What is the treatment for peri-orbital cellulitis?

Treatment of Periorbital Cellulitis

For mild periorbital (preseptal) cellulitis, initiate outpatient treatment with high-dose oral amoxicillin-clavulanate for 5-7 days with mandatory reassessment within 24-48 hours; however, hospitalize immediately for IV antibiotics if proptosis, visual changes, impaired extraocular movements, or systemic signs are present, as these indicate orbital (postseptal) involvement requiring aggressive management to prevent vision loss and life-threatening complications. 1, 2

Critical Distinction: Preseptal vs Postseptal

The fundamental management decision hinges on determining whether infection is confined anterior to the orbital septum (preseptal/periorbital) or has extended posterior to it (postseptal/orbital). 1

Clinical features distinguishing orbital cellulitis include: 1

• Proptosis
• Impaired or painful extraocular movements
• Decreased visual acuity
• Ophthalmoplegia

Risk factors suggesting postseptal involvement: 3

• Age >3 years
• High neutrophil count
• Gross periorbital edema
• Absence of infectious conjunctivitis
• Previous antibiotic therapy

Outpatient Management (Preseptal Cellulitis Only)

Eligibility criteria for outpatient treatment: 1, 2

• Eyelid less than 50% closed
• No proptosis or visual changes
• No systemic signs of infection
• Reliable follow-up available

First-line antibiotic: High-dose amoxicillin-clavulanate for 5-7 days, providing comprehensive coverage of Streptococcus pneumoniae, Haemophilus influenzae, Streptococcus pyogenes, and Staphylococcus aureus. 1, 2

MRSA coverage: If risk factors present (recent hospitalization, known colonization, failure of initial therapy), add vancomycin, clindamycin, trimethoprim-sulfamethoxazole, or doxycycline. 2

Mandatory reassessment within 24-48 hours is non-negotiable to detect progression to orbital involvement. 1, 2

Inpatient Management (Orbital Cellulitis)

All patients with orbital cellulitis require immediate hospitalization. 1

Initial IV Antibiotic Regimens

Preferred empiric therapy: 4, 1, 2

• High-dose amoxicillin-clavulanate IV, OR
• Ceftriaxone + clindamycin (particularly effective in pediatric series) 5
• Add vancomycin if MRSA suspected or severe infection

Alternative regimens for penicillin allergy: 2

• Clindamycin or vancomycin

The combination of ceftriaxone plus clindamycin provides excellent coverage for Streptococcus species (the predominant pathogens), Staphylococcus aureus, and anaerobes, which is critical since orbital cellulitis typically arises from ethmoid sinusitis. 5, 6

Imaging Protocol

CT orbits with IV contrast is the gold standard initial imaging to differentiate preseptal from postseptal cellulitis, identify abscesses, and detect complications like superior ophthalmic vein thrombosis or subdural empyema. 3, 1

Do not obtain precontrast imaging as it adds no diagnostic value in this scenario. 3

MRI head and orbits with and without contrast should be obtained if intracranial complications are suspected (cavernous sinus thrombosis, subdural empyema, meningitis). 3

Mandatory Consultations and Monitoring

Daily assessment of: 1

• Visual acuity
• Extraocular movements
• Pupillary response
• Degree of proptosis

Consult ophthalmology, otolaryngology, and infectious disease for all orbital cellulitis cases. 1, 2

Surgical Intervention

Surgery is required in approximately 38-49% of orbital cellulitis cases when medical management fails or large abscesses are present. 7, 6, 8

Indications for surgical drainage: 8

• Large subperiosteal abscesses (>1250 ml volume)
• Progression despite 24-48 hours of IV antibiotics
• Visual deterioration
• Intraconal or lateral abscesses

Surgical approach: Medial subperiosteal abscesses are typically drained endoscopically, while lateral or intraconal abscesses require open procedures. 8

Duration of Therapy

Continue IV antibiotics until significant clinical improvement (typically 8-10 days), then transition to oral antibiotics to complete 10-14 days total treatment. 4, 5

Common Pitfalls to Avoid

Delaying CT imaging when concerning features are present (proptosis, visual changes, ophthalmoplegia) can allow progression to vision-threatening complications. 1

Inadequate follow-up after initiating outpatient therapy - failure to reassess within 24-48 hours can miss progression to orbital involvement. 1

Not considering MRSA coverage when risk factors are present leads to treatment failure. 1, 2

Underestimating age-related differences: Children <5 years with preseptal cellulitis often have bacteremia (42% positive blood cultures) and risk of meningitis, while orbital cellulitis is more common in children >5 years and typically arises from sinusitis. 6, 9

Potential Complications

Untreated or inadequately treated orbital cellulitis can result in: 3, 4

• Permanent vision loss from optic nerve injury or retinal artery occlusion
• Cavernous sinus thrombosis
• Subdural empyema
• Brain abscess
• Meningitis

These catastrophic complications underscore why aggressive management with hospitalization, IV antibiotics, and close monitoring is mandatory for any suspected postseptal involvement. 3, 4