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 like ceftriaxone, vancomycin, or piperacillin-tazobactam in a hospital setting 1. It's essential to elevate the affected area, apply warm compresses, and take over-the-counter pain relievers like acetaminophen or ibuprofen as needed. Patients should complete the full course of antibiotics even if symptoms improve early to prevent recurrence or antibiotic resistance.

Some key considerations in treating cellulitis include:

• The use of antibiotics active against streptococci, as they are a common cause of cellulitis 1
• The consideration of broader-spectrum antibiotics, such as vancomycin, in cases where MRSA is suspected or in patients with severe infections 1
• The importance of elevating the affected area and applying warm compresses to reduce swelling and promote healing
• The need for patients to seek immediate medical attention if they develop fever, increasing pain, red streaking from the infection site, or if the affected area continues to expand despite 48 hours of antibiotic treatment

In terms of specific antibiotic regimens, options may include:

• Cephalexin (500 mg four times daily) for 5-6 days
• Dicloxacillin (500 mg four times daily) for 5-6 days
• Clindamycin (300-450 mg three times daily) for 5-6 days
• Vancomycin or other antibiotics effective against MRSA in cases where it is suspected or confirmed 1

Overall, the goal of treatment is to effectively manage the infection, reduce symptoms, and prevent complications, while also minimizing the risk of antibiotic resistance and promoting optimal patient outcomes.

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. Table 18 Cure Rates at the Test-of-Cure Visit for Microbiologically Evaluable Adult Patients with Complicated Skin and Skin Structure Infections Pathogen Cured ZYVOX n/N (%) Oxacillin/Dicloxacillin n/N (%) Staphylococcus aureus 73/83 (88) 72/84 (86) Methicillin-resistant S aureus 2/3 (67) 0/0 (-) Streptococcus agalactiae 6/6 (100) 3/6 (50) Streptococcus pyogenes 18/26 (69) 21/28 (75)

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 2.

• Linezolid is effective in treating complicated skin and skin structure infections, including those caused by Staphylococcus aureus and Streptococcus pyogenes.
• The cure rates for linezolid-treated patients with complicated skin and skin structure infections were 90%.
• Methicillin-resistant S aureus infections can be treated with linezolid, with a cure rate of 67% in microbiologically evaluable patients 2.
• The dosage and administration of linezolid for the treatment of infections, including complicated skin and skin structure infections, are described in Table 14 of the drug label 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.