What is the appropriate antibiotic treatment for possible cellulitis?

From the Guidelines

For possible cellulitis, empiric antibiotic treatment should begin with cephalexin 500mg orally four times daily for 5-7 days, or dicloxacillin 500mg orally four times daily for the same duration, as recommended by the most recent guidelines 1. These antibiotics effectively target Staphylococcus aureus and Streptococcus species, the most common causative organisms.

• The 2019 National Institute for Health and Care Excellence (NICE) guideline recommends a course of 5 to 7 days 1.
• The American College of Physicians also suggests that a short-course of antibiotics is sufficient for common infections, including cellulitis 1. If MRSA is suspected based on risk factors (prior MRSA infection, endemic area, purulent drainage), consider trimethoprim-sulfamethoxazole (TMP-SMX) 1-2 double-strength tablets twice daily or clindamycin 300-450mg orally four times daily, as recommended by the Infectious Diseases Society of America 2. Patients should elevate the affected limb when possible, mark the border of erythema to monitor progression, and seek immediate medical attention if fever develops, the infection spreads beyond the marked border, or symptoms worsen despite 48 hours of antibiotics. Adequate hydration and over-the-counter pain relievers like acetaminophen or ibuprofen can help manage symptoms. Cellulitis requires prompt treatment because the infection can spread rapidly through soft tissues, potentially leading to serious complications including bacteremia if left untreated. The most recent and highest quality study, the DANCE (Duration of Antibiotic Therapy for Cellulitis) RCT, compared a 6-day course of a penicillin (flucloxacillin) with the standard 12-day course and found overall similar rates of cure 1.

From the FDA Drug Label

14 CLINICAL STUDIES 14. 1 Acute Bacterial Skin and Skin Structure Infections Adults A total of 1333 adults with acute bacterial skin and skin structure infections (ABSSSI) were randomized in two multicenter, multinational, double-blind, non-inferiority trials. Both trials compared SIVEXTRO 200 mg once daily for 6 days versus linezolid 600 mg every 12 hours for 10 days In Trial 1, patients were treated with oral therapy, while in Trial 2, patients could receive oral therapy after a minimum of one day of intravenous therapy. Patients with cellulitis/erysipelas, major cutaneous abscess, or wound infection were enrolled in the trials

The types of ABSSSI included were cellulitis/erysipelas (41%), wound infection (29%), and major cutaneous abscess (30%) The types of ABSSSI included were cellulitis/erysipelas (50%), wound infection (30%), and major cutaneous abscess (20%)

Tedizolid (PO) can be used for the treatment of cellulitis/erysipelas, which is a type of Acute Bacterial Skin and Skin Structure Infections (ABSSSI).

• The medication was compared to linezolid in two multicenter, multinational, double-blind, non-inferiority trials.
• Patients with cellulitis/erysipelas were enrolled in the trials and received tedizolid 200 mg once daily for 6 days.
• The trials demonstrated the efficacy of tedizolid in treating ABSSSI, including cellulitis/erysipelas 3.

From the Research

Antibiotic Treatment for Possible Cellulitis

• The majority of non-purulent, uncomplicated cases of cellulitis are caused by β-hemolytic streptococci or methicillin-sensitive Staphylococcus aureus, and appropriate targeted coverage of this pathogen with oral antibiotics such as penicillin, amoxicillin, and cephalexin is sufficient 4.
• Home treatment with intravenous ceftriaxone is not inferior to treatment in hospital with intravenous flucloxacillin for children with cellulitis, and the standard of care for the intravenous treatment of uncomplicated cellulitis in children should be home or outpatient care when feasible 5.
• An evidence-based care pathway for cellulitis can improve process metrics, clinical outcomes, and cost for cellulitis by reducing broad-spectrum antibiotic use, pharmacy costs, and total facility costs without an adverse change in length of stay or 30-day readmissions 6.

Cost-Effectiveness of Antibiotic Treatment

• Treatment at home was less costly and more effective than standard hospital care for children with moderate or severe cellulitis, with a lower institutional cost per patient per episode and a lower mean cost incurred per family 7.
• There is no evidence of difference in clinical response rates for antibiotic route or duration, and the evidence base for antibiotic treatment decisions in cellulitis is flawed by biased comparisons, short follow-up, and lack of data around harms of antibiotic overuse 8.

Key Findings

• Oral antibiotics such as penicillin, amoxicillin, and cephalexin are sufficient for non-purulent, uncomplicated cases of cellulitis 4.
• Home treatment with intravenous ceftriaxone is a viable option for children with cellulitis 5.
• Evidence-based care pathways can improve outcomes and reduce costs for cellulitis 6.
• Treatment at home can be less costly and more effective than standard hospital care for children with moderate or severe cellulitis 7.
• Further research is needed to develop patient-tailored antibiotic prescribing for cellulitis to reduce unnecessary antibiotic use 8.