What is the treatment for cellulitis?

From the Guidelines

Cellulitis treatment should typically involve a 5- to 6-day course of antibiotics active against streptococci, such as cephalexin, dicloxacillin, or clindamycin, particularly for patients able to self-monitor and who have close follow-up with primary care. For mild cases, oral antibiotics are usually effective, while more severe cases may require intravenous antibiotics such as ceftriaxone, vancomycin, or piperacillin-tazobactam in a hospital setting 1.

Key Considerations

• The choice of antibiotic should be based on the severity of the infection and the presence of any underlying conditions, such as immunocompromisation or history of MRSA infection 1.
• Patients with cellulitis associated with penetrating trauma, evidence of MRSA infection elsewhere, nasal colonization with MRSA, injection drug use, or systemic inflammatory response syndrome (SIRS) may require broader antibiotic coverage, including vancomycin or another antimicrobial effective against both MRSA and streptococci 1.
• Elevation of the affected area, application of warm compresses, and use of over-the-counter pain relievers like acetaminophen or ibuprofen can help manage symptoms and promote healing 1.
• Proper wound care is essential if there's an entry point for the infection, and patients should complete the full course of antibiotics even if symptoms improve 1.

Special Cases

• In severely compromised patients, broad-spectrum antimicrobial coverage may be considered, and vancomycin plus either piperacillin-tazobactam or imipenem-meropenem is recommended as a reasonable empiric regimen for severe infections 1.
• For patients with nonpurulent cellulitis, a 5- to 6-day course of antibiotics active against streptococci is recommended, particularly for patients able to self-monitor and who have close follow-up with primary care 1.

From the FDA Drug Label

The cure rates in clinically evaluable patients with complicated skin and skin structure infections were 90% in linezolid-treated patients and 85% in oxacillin-treated patients The cure rates by pathogen for microbiologically evaluable patients are presented in Table 18. The cure rates for complicated skin and skin structure infections were:

• Staphylococcus aureus: 88%
• Methicillin-resistant S aureus: 67%
• Streptococcus agalactiae: 100%
• Streptococcus pyogenes: 69% The recommended dosage for linezolid formulations for the treatment of complicated skin and skin structure infections is 600 mg IV or oral every 12 hours for 10 to 14 days 2. For adult patients with infection due to MRSA, the treatment should be with linezolid 600 mg q12h 2.

From the Research

Cellulitis Treatment Overview

• Cellulitis is a common skin infection that can be challenging to diagnose and treat, with various infectious and non-infectious clinical mimickers 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 is sufficient 3.

Antibiotic Treatment

• A study comparing cephalexin plus trimethoprim-sulfamethoxazole versus cephalexin alone for the treatment of uncomplicated cellulitis found no significant difference in treatment success between the two groups 4.
• Another study comparing flucloxacillin with or without clindamycin for the treatment of limb cellulitis found no significant difference in improvement at day 5 between the two groups, but an increased risk of diarrhea in the clindamycin group 5.
• A study examining the route and duration of antibiotic therapy for cellulitis found no association between the route of administration and outcome, and no association between duration of antibiotic therapy and outcome 6.

Empiric Outpatient Therapy

• A retrospective cohort study of outpatients with cellulitis empirically treated with trimethoprim-sulfamethoxazole, cephalexin, or clindamycin found that trimethoprim-sulfamethoxazole had a higher treatment success rate than cephalexin, and clindamycin had higher success rates in patients with MRSA infections, moderately severe cellulitis, and obesity 7.
• Factors associated with treatment failure included therapy with an antibiotic that was not active against community-associated MRSA and severity of cellulitis 7.

Recommendations

• Antibiotics with activity against community-associated MRSA, such as trimethoprim-sulfamethoxazole and clindamycin, are preferred empiric therapy for outpatients with cellulitis in the community-associated MRSA-prevalent setting 7.
• Oral antibiotics such as penicillin, amoxicillin, and cephalexin are sufficient for non-purulent, uncomplicated cases of cellulitis 3.