From the Guidelines
Cellulitis treatment should begin with oral antibiotics that cover common skin pathogens like Staphylococcus aureus and Streptococcus species, with first-line options including cephalexin, dicloxacillin, or clindamycin for 5 days, as recommended by the Infectious Diseases Society of America 1. 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 1.
- For cellulitis with systemic signs of infection, systemic antibiotics are indicated, and coverage against methicillin-susceptible S. aureus (MSSA) may be considered 1.
- For patients with suspected MRSA, vancomycin or another antimicrobial effective against both MRSA and streptococci is recommended 1. While taking antibiotics, it is essential to elevate the affected area, apply warm compresses, and mark the border of the infection with a pen to monitor progression 1.
- Adequate pain control with acetaminophen or NSAIDs is also important.
- Patients should see improvement within 48-72 hours of starting antibiotics, and if the infection worsens, spreads beyond the marked borders, or if the patient develops fever, increasing pain, or systemic symptoms, they should seek immediate medical attention as hospitalization for IV antibiotics may be necessary 1. The recommended duration of antimicrobial therapy is 5 days, but treatment should be extended if the infection has not improved within this time period 1.
From the Research
Treatment of Cellulitis
- The treatment of cellulitis typically involves the use of antibiotics, with the choice of antibiotic depending on the severity and suspected cause of the infection 2.
- For non-purulent, uncomplicated cases of cellulitis, oral antibiotics such as penicillin, amoxicillin, and cephalexin are often sufficient 2.
- However, in areas with a high prevalence of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections, antibiotics with activity against MRSA, such as trimethoprim-sulfamethoxazole and clindamycin, may be preferred 3.
- A study comparing broad-spectrum and narrow-spectrum antibiotics found that narrow-spectrum antibiotics were effective in treating uncomplicated cellulitis, and that broad-spectrum antibiotics were not justified in this population 4.
- A systematic review and meta-analysis found that there was no evidence to support the superiority of any one antibiotic over another, and that antibiotics with activity against MRSA did not add an advantage 5.
Antibiotic Choices
- Cephalexin is a commonly used antibiotic for the treatment of cellulitis, and is often considered a cost-effective option 6.
- Clindamycin and trimethoprim-sulfamethoxazole are also effective against MRSA, and may be preferred in areas with a high prevalence of MRSA infections 3, 6.
- The choice of antibiotic should be based on the severity and suspected cause of the infection, as well as the patient's medical history and allergies.
Treatment Duration and Route of Administration
- The optimal duration of treatment for cellulitis is not well established, but is typically around 5-10 days 5.
- Oral antibiotics are often preferred over intravenous antibiotics, unless the patient is severely ill or has a compromised immune system 5.
- A study found that treatment duration of longer than 5 days was not supported by evidence, and that intravenous antibiotics were not necessary for uncomplicated cellulitis 5.