Oral antimicrobial therapy for cellulitis versus outpatient parenteral antimicrobial therapy: a single-centre audit of cellulitis outcomes

Background: Cellulitis is a common acute skin and soft tissue infection that causes substantial morbidity and healthcare costs.

Aims: To audit the impact on cellulitis management, regimen tolerability and outcomes of switching from outpatient parenteral antimicrobial therapy (OPAT) using intravenous (i.v.) cefazolin once daily plus probenecid to oral beta-lactam therapy (OBLT) using oral flucloxacillin plus probenecid.

Methods: We undertook a retrospective audit on cellulitis management, regimen tolerability and outcomes at the Dunedin Public Hospital Emergency Department (ED) before and after a change of the local outpatient cellulitis treatment pathway from OPAT using i.v. cefazolin once daily plus probenecid to OBLT using oral flucloxacillin plus probenecid.

Results: OPAT was used in 97/123 (78.9%) patients with cellulitis before compared to 1/70 (1.4%) after the pathway change (odds ratio (OR), 0.04, P < 0.01). OBLT was used in 26/123 (21.1%) patients with cellulitis before and 69/70 (98.6%) after (OR, 218.8, P < 0.01). Antimicrobial change due to intolerance occurred in 4/123 (3.2%) patients with cellulitis before and 4/70 (5.7%) after (OR, 1.8, P, not significant (NS)) the pathway change. Inpatient admission within 28 days occurred in 15/123 (12.2%) cellulitis patients before and 9/70 (12.9%) after (OR, 1.1, P, NS) the pathway change.

Conclusions: Implementation of a change in outpatient cellulitis treatment pathway resulted in a significant change in prescribing practice. Our findings suggest that OBLT was both tolerable and had similar outcomes to OPAT.