What is the treatment for periocular cellulitis?

Treatment of Periorbital Cellulitis

For periorbital cellulitis, hospitalize patients under 5 years old, those with systemic signs, or concern for orbital involvement, and initiate IV ceftriaxone plus metronidazole as first-line therapy. 1

Initial Assessment and Risk Stratification

When evaluating periorbital cellulitis, immediately distinguish between preseptal (periorbital) and orbital cellulitis, as these are distinct entities requiring different management approaches. 2

Key clinical features to assess:

• Preseptal cellulitis presents with eyelid erythema, warmth, and swelling WITHOUT proptosis, ophthalmoplegia, or vision changes 3, 4
• Orbital cellulitis presents with proptosis (64% of cases), chemosis (35.8%), and potentially ophthalmoplegia, indicating infection posterior to the orbital septum 3, 4
• Obtain orbital CT scan if any concern for orbital involvement exists 4

Predisposing factors to identify:

• Upper respiratory infection (68% of preseptal cases) 3
• Sinusitis (79% of orbital cases, 22% overall) 3, 4
• Eyelid trauma (20% of cases) 3

Hospitalization Criteria

Admit patients with ANY of the following: 1

• Age under 5 years
• Systemic inflammatory response syndrome (fever, tachycardia, leukocytosis)
• Any concern for orbital involvement (proptosis, ophthalmoplegia, vision changes)
• Inability to tolerate oral intake
• Anticipated poor adherence to outpatient therapy

Children under 5 years represent 85% of preseptal cellulitis cases and warrant hospitalization due to higher risk of progression. 3

Antibiotic Selection

First-Line Intravenous Therapy (Hospitalized Patients)

Ceftriaxone PLUS metronidazole is the optimal initial regimen: 1

• Adults: Ceftriaxone 1 g IV every 24 hours + metronidazole 500 mg IV every 8 hours
• Children: Ceftriaxone 50-75 mg/kg/day IV + metronidazole 7.5 mg/kg IV every 8 hours

This combination provides coverage against the predominant pathogens (Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus species) and is associated with shorter hospital stays and reduced need for surgical intervention. 1, 3

Alternative regimen: Ceftriaxone plus clindamycin has been used successfully, with mean treatment duration of 8.6 days. 3

Outpatient Oral Therapy (Selected Cases)

For mild preseptal cellulitis in older children (>5 years) without systemic signs who can be monitored closely:

• Amoxicillin-clavulanate is the most commonly used oral agent 4
• Dosing follows standard cellulitis protocols: 875/125 mg twice daily (adults) 5

Critical caveat: Community-acquired MRSA is emerging as a significant pathogen in periocular infections. 6 If MRSA risk factors are present (prior MRSA exposure, purulent drainage, treatment failure), add MRSA coverage with clindamycin or vancomycin. 5, 6

Treatment Duration

• Standard duration: 5 days if clinical improvement occurs 5, 1
• Extension indicated only if symptoms have not improved within this timeframe 5, 1
• Mean hospital stay: 3 days for preseptal cases, 8 days for orbital cases 4

Adjunctive Measures

Elevation of the affected area promotes drainage of edema and is associated with reduced progression to surgery, particularly when sinusitis is present. 1

Surgical Intervention Criteria

Surgery is required in 6-7% of pediatric cases and up to 19.2% of adults who fail medical management. 1, 4

Indications for surgical consultation: 1

• Abscess formation (subperiosteal or orbital)
• Progressive proptosis despite 24-48 hours of IV antibiotics
• Vision deterioration
• No improvement after 24-48 hours of appropriate IV antibiotics

Subperiosteal abscess occurs in 12% of cases and orbital abscess in 3%, both typically requiring surgical drainage. 4

Common Pitfalls to Avoid

• Do not delay CT imaging if any orbital signs are present—distinguishing preseptal from orbital cellulitis is critical for management decisions 2, 4
• Do not use beta-lactam monotherapy alone for periocular cellulitis—the combination of ceftriaxone plus metronidazole provides superior coverage for polymicrobial infections associated with sinusitis 1
• Do not discharge young children (<5 years) with periorbital cellulitis for outpatient management—they require hospitalization 1, 3
• Watch for necrotizing fasciitis, which can be easily missed early in its course and represents a devastating complication 6

Monitoring and Follow-Up

Reassess all patients within 24-48 hours to verify clinical response. 5 Progression despite appropriate antibiotics indicates either resistant organisms (consider MRSA), orbital involvement requiring surgery, or an alternative diagnosis. 7, 6