What is the antibiotic of choice for periorbital cellulitis?

From the Guidelines

The antibiotic of choice for periorbital cellulitis is typically amoxicillin-clavulanate (Augmentin). For adults, the recommended dosage is 875 mg/125 mg orally twice daily for 7-10 days. For children, the dosage is 45 mg/kg/day divided twice daily.

Key Considerations

• In cases of severe infection or in patients with penicillin allergy, alternatives include clindamycin (300-450 mg orally four times daily for adults; 30-40 mg/kg/day divided three times daily for children) or trimethoprim-sulfamethoxazole plus cephalexin 1.
• For hospitalized patients with more severe infections, intravenous antibiotics such as ampicillin-sulbactam (3 g IV every 6 hours) or ceftriaxone plus metronidazole may be necessary.
• Periorbital cellulitis is commonly caused by Staphylococcus aureus, Streptococcus species, and anaerobes, which is why broad-spectrum coverage is needed 1.
• Treatment should be initiated promptly to prevent spread of infection to the orbital tissues, which could lead to serious complications including vision loss.
• Clinical improvement should be seen within 24-48 hours; if not, reassessment and possible imaging to rule out orbital involvement is warranted.

Treatment Duration

• The recommended duration of antimicrobial therapy is 5 days, but treatment should be extended if the infection has not improved within this time period 1.

Patient Management

• Elevation of the affected area and treatment of predisposing factors, such as edema or underlying cutaneous disorders, are recommended 1.
• Outpatient therapy is recommended for patients who do not have SIRS, altered mental status, or hemodynamic instability 1.
• Hospitalization is recommended if there is concern for a deeper or necrotizing infection, for patients with poor adherence to therapy, for infection in a severely immunocompromised patient.

From the FDA Drug Label

Amoxicillin/clavulanic acid has been shown to be active against most isolates of the following bacteria, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section Gram-positive bacteria Staphylococcus aureus Gram-negative bacteria Enterobacter species Escherichia coli Haemophilus influenzae Klebsiella species Moraxella catarrhalis

The antibiotic of choice for periorbital cellulitis is amoxicillin-clavulanate.

• Key points:
  • Amoxicillin/clavulanic acid is active against Staphylococcus aureus and Haemophilus influenzae, which are common causes of periorbital cellulitis.
  • The formulation of amoxicillin and clavulanic acid in amoxicillin and clavulanate potassium protects amoxicillin from degradation by some beta-lactamase enzymes and extends the antibiotic spectrum of amoxicillin to include many bacteria normally resistant to amoxicillin 2.

From the Research

Antibiotic Choices for Periorbital Cellulitis

• The choice of antibiotic for periorbital cellulitis depends on various factors, including the causative bacteria and the patient's age and medical history 3, 4.
• According to a study published in 1996, sulbactam-ampicillin (SAM) can be the first line of drug treatment for periorbital cellulitis, as it is easily used in every age group and etiology, and provides total recovery with less side effects and risk of recurrence 3.
• However, another study published in 2022 found that vancomycin is ideal for methicillin-resistant Staphylococcus aureus (MRSA) infections, which are becoming increasingly common in pediatric periorbital cellulitis 4.
• A case report published in 2015 also highlights the importance of early incision and drainage of periorbital abscesses, and the use of intravenous vancomycin for MRSA sepsis 5.
• A retrospective cohort study published in 2022 found that methicillin-susceptible S. aureus was the most common organism, and vancomycin use fluctuated annually, with surgery performed in 39.5% of patients 6.
• Guidelines for the management of periorbital cellulitis/abscess published in 2004 suggest that antimicrobial therapy should be based on the suspected causative organism, and that CT scanning should be used to distinguish between preseptal and orbital involvement 7.

Common Causative Bacteria

• Staphylococcus aureus is a common causative bacteria of periorbital cellulitis, with methicillin-resistant S. aureus (MRSA) infections becoming increasingly common 4, 6.
• Other causative bacteria include Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis 3, 7.

Treatment Duration

• The duration of antibiotic treatment for periorbital cellulitis can vary, but a study published in 2022 found that treatment failure was uncommon in patients who received ≤ 2 weeks of therapy, suggesting that shorter durations may be adequate in some patients 6.
• Another study published in 1996 found that the duration of treatment with sulbactam-ampicillin (SAM) was generally between 7 and 10 days 3.