What is the appropriate antibiotic to prescribe for cellulitis of the buttock?

From the Guidelines

For cellulitis of the buttock, the most appropriate antibiotic to prescribe is one that is active against streptococci, such as cephalexin 500mg orally four times daily for outpatient management. According to the 2014 update by the Infectious Diseases Society of America 1, typical cases of cellulitis without systemic signs of infection should receive an antimicrobial agent that is active against streptococci. 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.

Some key points to consider when prescribing antibiotics for cellulitis of the buttock include:

• Coverage against MSSA may be included, especially in patients with systemic signs of infection or severe disease 1
• Vancomycin or another antimicrobial effective against both MRSA and streptococci may be recommended for patients with penetrating trauma, evidence of MRSA infection elsewhere, nasal colonization with MRSA, injection drug use, purulent drainage, or SIRS 1
• Elevation of the affected area and treatment of predisposing factors, such as edema or underlying cutaneous disorders, are also recommended 1
• Outpatient therapy is recommended for patients who do not have SIRS, altered mental status, or hemodynamic instability, while hospitalization is recommended for more severe cases or those with poor adherence to therapy 1

In terms of specific antibiotic regimens, cefazolin 1-2g IV every 8 hours for hospitalized patients or cephalexin 500mg orally four times daily for outpatient management are commonly used options. For patients with penicillin allergy, clindamycin 300-450mg orally four times daily or 600-900mg IV every 8 hours is an appropriate alternative. If MRSA is suspected, consider adding trimethoprim-sulfamethoxazole (TMP-SMX) 1-2 double-strength tablets twice daily or doxycycline 100mg twice daily. Clinical improvement should be evident within 48-72 hours; if not, reassessment and possible antibiotic adjustment may be necessary.

From the FDA Drug Label

Clindamycin is indicated in the treatment of serious infections caused by susceptible anaerobic bacteria. Clindamycin is also indicated in the treatment of serious infections due to susceptible strains of streptococci, pneumococci, and staphylococci Serious skin and soft tissue infections; septicemia; intra- abdominal infections such as peritonitis and intra-abdominal abscess Streptococci: Serious respiratory tract infections; serious skin and soft tissue infections. Staphylococci: Serious respiratory tract infections; serious skin and soft tissue infections. infections of the female pelvis and genital tract such as endometritis, nongonococcal tubo-ovarian abscess, pelvic cellulitis, and postsurgical vaginal cuff infection.

Clindamycin can be an appropriate antibiotic to prescribe for cellulitis of the buttock 2, as it is indicated for the treatment of serious skin and soft tissue infections, including those caused by streptococci and staphylococci.

• The dosage for adults with serious infections is 150 to 300 mg every 6 hours 2.
• It is essential to consider the causative organisms and their susceptibility to clindamycin before prescribing 2.

From the Research

Antibiotic Treatment for Cellulitis of the Buttock

• The choice of antibiotic for cellulitis, including cases affecting the buttock, does not have a clear consensus in the medical community 3, 4.
• Studies suggest that the route of antibiotic administration (intravenous vs. oral) may not significantly impact the outcome for patients with similar severity of cellulitis 3.
• There is no strong evidence to support the use of one antibiotic over another for the treatment of cellulitis, including those with activity against methicillin-resistant Staphylococcus aureus 4.
• The duration of antibiotic therapy also lacks clear guidelines, with no association found between the length of treatment and clinical outcome 3, 4.
• A systematic review and meta-analysis found that treatment duration longer than 5 days and the use of intravenous antibiotics over oral antibiotics were not supported by evidence 4.
• The current evidence base is considered low-quality, highlighting the need for future trials to standardize outcomes, including severity scoring, dosing, and duration of therapy 4.