What is the treatment for cellulitis?

From the Guidelines

Cellulitis should be treated with antibiotics that are active against streptococci, with a recommended duration of 5 days, but treatment should be extended if the infection has not improved within this time period 1.

Treatment Options

• For mild cases, oral antibiotics like cephalexin (500 mg four times daily), dicloxacillin (500 mg four times daily), or amoxicillin-clavulanate (875/125 mg twice daily) for 5-10 days are usually effective.
• More severe cases may require intravenous antibiotics such as ceftriaxone (1-2 g daily) or vancomycin (15-20 mg/kg every 8-12 hours) in a hospital setting.

Management

• While taking antibiotics, elevate the affected area, rest, and apply warm compresses to reduce swelling and pain.
• Over-the-counter pain relievers like acetaminophen or ibuprofen can help manage discomfort.
• It's crucial to complete the full course of antibiotics even if symptoms improve quickly.

Important Considerations

• Cellulitis treatment works by targeting the bacteria causing the infection, typically Streptococcus and Staphylococcus species, preventing them from multiplying and allowing your immune system to clear the infection.
• Seek immediate medical attention if you develop fever, increasing pain, or if the redness spreads rapidly, as these may indicate worsening infection requiring more aggressive treatment.
• The choice of antibiotic should be based on the severity of the infection and the presence of any underlying medical conditions, with consideration of the potential for methicillin-resistant Staphylococcus aureus (MRSA) infection 1.

From the FDA Drug Label

The two trials were similar in design but differed in patient characteristics, including history of diabetes and peripheral vascular disease. There were a total of 534 adult patients treated with daptomycin for injection and 558 treated with comparator in the two trials. Table 15: Investigator’s Primary Diagnosis in the cSSSI Trials in Adult Patients (Population: ITT) Primary Diagnosis Adult Patients (Daptomycin for Injection/ Comparator* ) Wound Infection 99 (38%) / 116 (44%) 102 (38%) / 108 (37%) 201 (38%) / 224 (40%) Major Abscess 55 (21%) / 43 (16%) 59 (22%) / 65 (22%) 114 (21%) / 108 (19%) Ulcer Infection 71 (27%) / 75 (28%) 53 (20%) / 68 (23%) 124 (23%) / 143 (26%) Other Infection † 39 (15%) / 32 (12%) 56 (21%) / 51 (18%) 95 (18%) / 83 (15%) †The majority of cases were subsequently categorized as complicated cellulitis, major abscesses, or traumatic wound infections.

Cellulitis treatment can be achieved with daptomycin for injection. The clinical success rates for complicated skin and skin structure infections, including cellulitis, were similar between daptomycin and the comparator drugs (vancomycin or an anti-staphylococcal semi-synthetic penicillin) 2.

• Daptomycin for injection was administered at a dose of 4 mg/kg IV q24h.
• The majority of cases of "other infection" were subsequently categorized as complicated cellulitis.
• Clinical success rates in the ITT population were 62.5% to 80.4% in patients treated with daptomycin for injection.

Alternatively, linezolid can also be used for the treatment of complicated skin and skin structure infections, including cellulitis 3.

• The recommended dosage for linezolid is 600 mg IV or oral q12h for adults.
• For pediatric patients, the dosage is 10 mg/kg IV or oral q8h.

From the Research

Cellulitis Treatment Overview

• Cellulitis is a common skin infection that can be challenging to diagnose and treat, with various clinical presentations and mimickers 4.
• The majority of non-purulent, uncomplicated cases of cellulitis are caused by β-hemolytic streptococci or methicillin-sensitive Staphylococcus aureus, and targeted coverage with oral antibiotics such as penicillin, amoxicillin, and cephalexin is sufficient 4.

Antibiotic Treatment

• A study comparing flucloxacillin with or without clindamycin for the treatment of limb cellulitis found no significant difference in improvement at day 5, but an increased risk of diarrhea with the addition of clindamycin 5.
• Another study suggested that the addition of an oral anti-inflammatory agent to antibiotic treatment may hasten the resolution of cellulitis-related inflammation 6.
• Data extracted from a clinical trial found that oral antibiotic therapy was as effective as intravenous therapy, and that the duration of treatment did not affect outcome 7.
• A randomized, double-blind, placebo-controlled trial found that a 6-day course of antibiotic treatment resulted in more frequent relapses by day 90 compared to a 12-day course, but the confidence intervals were wide and the hypothesis that 6 days is non-inferior to 12 days could not be confirmed or refuted 8.

Treatment Duration and Route

• There is uncertainty about the benefit of intravenous over oral antibiotic therapy, and the appropriate duration of treatment for cellulitis 7.
• A study found that patients who received only oral therapy were more likely to improve at day 5, and were as likely to return to normal activities at day 10 and day 30, compared to those who received intravenous therapy 7.
• The optimal duration of antibiotic treatment for cellulitis is still unclear, with some studies suggesting that a shorter course may be sufficient, while others find that a longer course may be necessary to prevent relapse 7, 8.