What are the treatment options for outpatient management of cellulitis?

From the Guidelines

Outpatient treatment for cellulitis should typically involve oral antibiotics targeting common skin pathogens, with first-line therapy being cephalexin 500 mg four times daily for 5 days, as this duration has been shown to be as effective as 10 days if clinical improvement occurs by 5 days 1. The choice of antibiotic should be based on the severity of the infection and the presence of any underlying conditions, such as penicillin allergies. For patients with penicillin allergies, clindamycin 300-450 mg three times daily or trimethoprim-sulfamethoxazole (TMP-SMX) one double-strength tablet twice daily are appropriate alternatives. If MRSA is suspected, doxycycline 100 mg twice daily or TMP-SMX should be considered, especially in cases associated with penetrating trauma, purulent drainage, or evidence of MRSA infection elsewhere 1. Patients should elevate the affected limb when possible, mark the border of erythema to monitor progression, take the full course of antibiotics even if symptoms improve, and maintain good wound care if there's an entry point. Adequate hydration and over-the-counter pain relievers like acetaminophen or ibuprofen can help manage symptoms. Some key considerations in the management of cellulitis include:

• The role of cultures in guiding antibiotic therapy, which is generally not recommended for routine cases but may be considered in specific situations such as severe infection or immunocompromised patients 1.
• The importance of treating predisposing factors, such as tinea pedis or venous eczema, to prevent recurrence 1.
• The need for hospitalization in cases of severe infection, poor adherence to therapy, or significant comorbidities 1. Patients should seek immediate medical attention if they develop fever over 101°F, rapidly spreading redness, increasing pain, or red streaking from the infection site, as these may indicate worsening infection requiring intravenous antibiotics. These antibiotic choices target the most common causative organisms in cellulitis—Streptococcus and Staphylococcus species—while providing appropriate tissue penetration to reach the infection site in the dermis and subcutaneous tissues. It's also important to note that outpatient therapy is recommended for patients who do not have systemic inflammatory response syndrome (SIRS), altered mental status, or hemodynamic instability, and that hospitalization is recommended if there is concern for a deeper or necrotizing infection, for patients with poor adherence to therapy, or for infection in a severely immunocompromised patient 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%)

Outpatient treatment for cellulitis can be done with tedizolid (PO) 200 mg once daily for 6 days, as it has been compared to linezolid in clinical trials for the treatment of acute bacterial skin and skin structure infections (ABSSSI), which includes cellulitis/erysipelas 2.

• Key points:
  • Tedizolid can be used for outpatient treatment of cellulitis.
  • The recommended dosage is 200 mg once daily for 6 days.
  • Tedizolid has been compared to linezolid in clinical trials for ABSSSI, including cellulitis/erysipelas.

From the Research

Outpatient Treatment for Cellulitis

• Most patients with cellulitis can be treated as outpatients with oral antibiotics, such as dicloxacillin or cephalexin, when methicillin-resistant Staphylococcus aureus is not a concern 3.
• A study found that oral beta-lactam therapy (OBLT) using oral flucloxacillin plus probenecid was both tolerable and had similar outcomes to outpatient parenteral antimicrobial therapy (OPAT) for cellulitis treatment 4.
• The implementation of an evidence-based care pathway for cellulitis can improve process metrics, clinical outcomes, and cost, with a significant decrease in broad-spectrum antibiotic use and pharmacy costs 5.
• A systematic review and meta-analysis found that there is no evidence to support the superiority of any one antibiotic over another for cellulitis treatment, and that antibiotics with activity against methicillin-resistant Staphylococcus aureus did not add an advantage 6.
• Antibiotic selection for cellulitis treatment should be determined by patient history and risk factors, severity of clinical presentation, and the most likely microbial culprit 7.

Key Considerations

• Cellulitis diagnosis can be challenging due to the lack of a gold standard diagnostic test, and thorough history and clinical examination are necessary to narrow the differential diagnosis 7.
• The use of intravenous antibiotics over oral antibiotics and treatment duration of longer than 5 days are not supported by evidence 6.
• Outpatient treatment pathways for cellulitis can be effective and reduce healthcare costs, with a significant decrease in hospital admissions and readmissions 4, 5.