What is the treatment for cellulitis in an immunocompetent patient?

From the Guidelines

For immunocompetent patients with cellulitis, empiric treatment with oral antibiotics active against streptococci is recommended, with a typical duration of 5 days, as stated in the 2014 update by the Infectious Diseases Society of America 1.

Key Considerations

• The choice of antibiotic should be based on the severity of the infection and the presence of systemic signs of infection.
• For typical cases of cellulitis without systemic signs of infection, an antimicrobial agent active against streptococci is recommended, such as penicillin, amoxicillin, or cephalexin 1.
• For patients with penicillin allergy, clindamycin is an alternative option 1.
• If MRSA is suspected based on risk factors or local prevalence, consider adding coverage with trimethoprim-sulfamethoxazole (TMP-SMX) or doxycycline 1.

Treatment Approach

• Mild to moderate cases can be treated with oral antibiotics, such as cephalexin 500 mg orally four times daily for 5-7 days, or dicloxacillin 500 mg orally four times daily for 5-7 days.
• Severe cases requiring hospitalization should receive intravenous antibiotics, such as cefazolin 1-2 g every 8 hours or vancomycin if MRSA is suspected.
• In addition to antibiotics, patients should elevate the affected limb to reduce swelling, mark the border of erythema to monitor progression, and maintain adequate hydration.

Monitoring and Reassessment

• Fever, increasing pain, expanding erythema beyond marked borders, or lack of improvement within 48-72 hours warrants reassessment and potential adjustment of the treatment plan 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 treatment for an immunocompetent patient with cellulitis is tedizolid (SIVEXTRO) 200 mg once daily for 6 days or linezolid 600 mg every 12 hours for 10 days, as both treatments were compared in clinical trials for acute bacterial skin and skin structure infections (ABSSSI), which included cellulitis/erysipelas 2.

From the Research

Treatment of Cellulitis in Immunocompetent Patients

• The treatment of cellulitis in immunocompetent patients typically involves the use of oral antibiotics, with dicloxacillin or cephalexin being the oral therapy of choice when methicillin-resistant Staphylococcus aureus is not a concern 3.
• 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.
• Empiric antibiotic choices are designed against the background of a low prevalence of multi-resistant Staphylococcus aureus 5.

Route and Duration of Antibiotic Therapy

• There is uncertainty about the benefit of intravenous (IV) over oral (PO) antibiotic therapy, and the appropriate duration of treatment for cellulitis 6.
• Patients given only PO therapy were more likely to have improved at day 5 compared with those given at least a single dose of IV therapy, and were as likely to be back to their normal activities at day 10 and day 30 6.
• There was no association between duration of antibiotic therapy and outcome as measured at day 10 and day 30 6.

Evidence-Based Care Pathway

• The implementation of an evidence-based care pathway for cellulitis can improve process, clinical, and cost outcomes, including a decrease in the use of broad-spectrum antibiotics and a reduction in pharmacy and total facility costs 7.
• The use of an evidence-based care pathway can also reduce the length of stay and 30-day readmissions for patients with cellulitis 7.