What are the options for antibiotic therapy for preseptal cellulitis?

Antibiotic Therapy for Preseptal Cellulitis

For preseptal cellulitis, first-line treatment should be an antibiotic active against streptococci, with coverage for MRSA only in specific risk situations. 1

First-Line Treatment Options

• For mild cases (outpatient treatment):

  • Penicillin or amoxicillin (if streptococcal infection is suspected) 1
  • Dicloxacillin or cephalexin (if S. aureus coverage is desired) 1
  • Clindamycin (good option for both streptococcal and staphylococcal coverage) 2
  • Amoxicillin-clavulanate (broader coverage for mixed infections) 1

• For moderate to severe cases (requiring hospitalization):

  • Cefazolin IV (33 mg/kg/dose in children, 1g every 8h in adults) 1
  • Nafcillin IV (50 mg/kg/dose in children, 1-2g every 4-6h in adults) 1

When to Consider MRSA Coverage

MRSA is an unusual cause of typical preseptal cellulitis, but coverage should be considered in cases with:

• Penetrating trauma 1
• Evidence of purulent drainage 1
• Evidence of MRSA infection elsewhere 1
• History of injection drug use 1
• Systemic inflammatory response syndrome (SIRS) 1
• Lack of response to beta-lactam antibiotics 3

MRSA Treatment Options

• For outpatient treatment:

  • Trimethoprim-sulfamethoxazole (consider adding a beta-lactam for streptococcal coverage) 3
  • Clindamycin (if local resistance rates are low) 3
  • Linezolid 600mg twice daily (for resistant cases) 3

• For inpatient treatment:

  • Vancomycin IV (15 mg/kg every 12 hours) 3
  • Linezolid IV/oral (shown to have higher success rates than vancomycin in some studies) 3
  • Daptomycin IV (4 mg/kg daily) 3
  • Telavancin IV 3

Duration of Therapy

• A 5-day course of antimicrobial therapy is as effective as a 10-day course if clinical improvement has occurred by day 5 1, 3
• Treatment should be extended if the infection has not improved within this time period 1

Special Considerations for Pediatric Patients

• Preseptal cellulitis is more common in children than adults 2
• Common symptoms include eyelid swelling and edema (100%), fever (41.2%), eye discharge (30.1%), and tenderness (19.9%) 2
• Most commonly used antibiotics in pediatric cases are clindamycin (72.8%), ceftriaxone (54.4%), and vancomycin (27.2%) 2
• Young infants with difficult eye examination or those presenting with headache or vomiting should raise suspicion for orbital cellulitis rather than preseptal cellulitis 4

Distinguishing Preseptal from Orbital Cellulitis

• Preseptal cellulitis involves only the eyelid, whereas orbital cellulitis involves structures of the orbit 1
• Mild cases of preseptal cellulitis (eyelid <50% closed) may be treated on an outpatient basis 1
• If proptosis, impaired visual acuity, or impaired/painful extraocular mobility is present, hospitalization and imaging are indicated 1
• CT scan is essential to confirm or rule out orbital involvement in uncertain cases 1, 5

Treatment of Complications

• If the patient does not improve within 24-48 hours or if infection is progressive, hospitalization is recommended 1
• For severe cases with orbital involvement, consultation with ophthalmology, otolaryngology, and infectious disease specialists may be appropriate 1

Common Pitfalls to Avoid

• Failing to distinguish between preseptal and orbital cellulitis 4
• Not considering MRSA in cases with specific risk factors 1
• Inadequate treatment of predisposing factors (such as sinusitis or odontogenic infections) 2
• Overlooking orbital involvement in young infants with difficult examination 4