What is the recommended treatment for preseptal cellulitis?

Treatment of Preseptal Cellulitis

For mild to moderate preseptal cellulitis, treat with oral antibiotics targeting beta-hemolytic streptococci—specifically penicillin, amoxicillin, dicloxacillin, or cephalexin for 5 days, extending treatment only if no improvement is seen. 1

First-Line Antimicrobial Selection

Outpatient Treatment (Mild to Moderate Cases)

• Oral antibiotics active against streptococci are the cornerstone of therapy, including penicillin, amoxicillin, dicloxacillin, or cephalexin. 1
• High-dose amoxicillin-clavulanate provides comprehensive coverage, particularly when preseptal cellulitis is associated with acute bacterial sinusitis (eyelid <50% closed). 1, 2
• Treatment duration is 5 days, extending only if clinical improvement is not evident after this period. 1, 2
• For penicillin-allergic patients, use clindamycin or erythromycin as alternatives. 1

Pediatric Considerations

• Children should receive the same antibiotic approach as adults, with oral options including penicillin, amoxicillin, amoxicillin-clavulanate, dicloxacillin, cefalexin, or clindamycin. 1
• High-dose amoxicillin-clavulanate with daily follow-up until definite improvement is noted for mild cases in children. 1

When to Add MRSA Coverage

• MRSA coverage is NOT routinely needed for typical preseptal cellulitis. 1
• Consider MRSA-active antibiotics (vancomycin or alternatives) when specific risk factors are present: 1
  • Penetrating trauma
  • Evidence of MRSA infection elsewhere
  • Nasal colonization with MRSA
  • Injection drug use
  • Purulent drainage

Hospitalization Criteria and Severe Cases

Indications for Admission

• Hospitalize patients with any of the following: 1
  • Systemic inflammatory response syndrome (SIRS)
  • Altered mental status or hemodynamic instability
  • Concern for deeper infection (orbital involvement)
  • Immunocompromised status
  • Failed outpatient treatment
  • No improvement within 24-48 hours of oral antibiotics 1

Intravenous Antibiotic Regimens

• For severe infections requiring hospitalization, use vancomycin or another antimicrobial effective against both MRSA and streptococci. 1
• For severe infections with orbital complications, vancomycin provides coverage for possible methicillin-resistant S. pneumoniae. 1
• For moderate to severe cases, consider vancomycin plus either piperacillin-tazobactam or imipenem/meropenem. 2

Adjunctive Measures

• Elevate the affected area to promote gravity drainage of edema—failure to do this delays improvement. 1, 2
• Consider systemic corticosteroids (prednisone 40 mg daily for 7 days) in non-diabetic adult patients to hasten resolution. 1
• Corticosteroids are preferred in patients with orbital involvement (73.3% vs 8.6% in preseptal cases). 3

Monitoring and Follow-Up

• Patients should show improvement within 24-48 hours of appropriate antibiotic therapy. 1
• Daily assessment until definite improvement is noted is recommended. 2
• If no improvement within 72 hours, consider: 1
  • Changing antibiotics
  • Imaging (contrast-enhanced CT) to rule out orbital involvement or abscess formation
  • Hospital admission for IV antibiotics

Red Flags Requiring Immediate Imaging and Specialist Consultation

• If proptosis, impaired visual acuity, or impaired/painful extraocular mobility is present, hospitalize and perform contrast-enhanced CT. 1
• Consult otolaryngology, ophthalmology, and infectious disease for guidance regarding surgical intervention and antimicrobial selection. 1

Prevention of Recurrence

• Identify and treat predisposing conditions such as sinusitis, edema, and toe web abnormalities. 1
• For patients with 3-4 episodes per year despite addressing predisposing factors, consider prophylactic antibiotics such as oral penicillin or erythromycin twice daily for 4-52 weeks. 1

Critical Pitfalls to Avoid

• Never use fluoroquinolones as first-line therapy—they have inadequate streptococcal coverage despite approval for uncomplicated cellulitis. 1
• Not elevating the affected area delays improvement. 1
• Inadequate treatment duration when clinical improvement is not evident after 5 days. 1
• Failure to recognize progression from preseptal to orbital cellulitis can lead to permanent blindness if not treated promptly. 2
• Inadequate antibiotic coverage for both streptococci and staphylococci can lead to treatment failure. 2

Differential Diagnosis Considerations

• C-reactive protein >120 mg/L is a useful cut-off point suggesting orbital rather than preseptal cellulitis. 3
• Diplopia, ophthalmoplegia, and proptosis are only present in orbital cellulitis, not preseptal. 3
• Fever is more common in orbital cellulitis (82.2%) compared to preseptal (51.5%). 3