What type of antibiotics is effective for treating skin infections, specifically bacterial infections such as cellulitis or abscesses?

From the Guidelines

For skin infections, the most effective antibiotic treatment is often a 5- to 7-day course of antibiotics active against streptococci and Staphylococcus aureus, including MRSA. The choice of antibiotic depends on the severity of infection, patient allergies, and local resistance patterns 1.

Key Considerations

• For mild infections, topical antibiotics like mupirocin (Bactroban) applied three times daily for 7-10 days may be sufficient.
• For patients with penicillin allergies, clindamycin 300-450 mg three times daily for 7-10 days is a good alternative.
• If MRSA (methicillin-resistant Staphylococcus aureus) is suspected, trimethoprim-sulfamethoxazole (Bactrim) 1-2 double-strength tablets twice daily for 7-10 days, or doxycycline 100 mg twice daily for 7-10 days may be more appropriate.
• First-line treatment often includes cephalexin (Keflex) 500 mg four times daily for 7-10 days, or dicloxacillin 500 mg four times daily for 7-10 days.

Important Factors

• The 2014 IDSA guideline recommends that patients should receive antibiotics for uncomplicated cellulitis but that clinicians should consider extending treatment if the infection has not improved after 5 days 1.
• The more recent 2019 National Institute for Health and Care Excellence (NICE) guideline recommends a course of 5 to 7 days 1.
• Further study is needed to evaluate the optimal duration of antibiotic therapy for SSTIs 1.

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 Vancomycin Hydrochloride for Injection, USP is indicated for the treatment of serious or severe infections caused by susceptible strains of methicillin-resistant (β-lactam-resistant) staphylococci Adult patients with clinically documented complicated skin and skin structure infections were enrolled in a randomized, multi-center, double-blind, double-dummy trial comparing study medications administered IV followed by medications given orally for a total of 10 to 21 days of treatment. One group of patients received ZYVOX I. V. Injection 600 mg q12h followed by ZYVOX Tablets 600 mg q12h; the other group received oxacillin 2 g every 6 hours (q6h) IV followed by dicloxacillin 500 mg q6h orally.

Antibiotics for skin infections include:

• Linezolid (2) for complicated skin and skin structure infections
• Clindamycin (3) for serious skin and soft tissue infections
• Vancomycin (4) for serious or severe infections caused by susceptible strains of methicillin-resistant staphylococci, including skin and skin structure infections. The choice of antibiotic depends on the causative organism and its susceptibility to the antibiotic.

From the Research

Types of Antibiotics for Skin Infections

• Cephalexin is an effective antibiotic for the treatment of streptococcal and staphylococcal skin infections, with cure rates of 90% or higher 5.
• Penicillinase-resistant penicillins, such as flucloxacillin and dicloxacillin, are the antibiotics of choice for the management of serious methicillin-susceptible S. aureus (MSSA) infections 6.
• First-generation cephalosporins, such as cefazolin, cephalothin, and cephalexin, have important therapeutic roles in less serious MSSA infections, such as skin and soft tissue infections 6.
• Clindamycin, lincomycin, and erythromycin are also effective against MSSA infections, but cephalosporins are contra-indicated in patients with immediate penicillin hypersensitivity 6.
• For methicillin-resistant S. aureus (MRSA) infections, vancomycin or teicoplanin are recommended for serious infections, while lincosamides, such as clindamycin, or cotrimoxazole are recommended for less serious infections 6.

Specific Antibiotics for Skin Infections

• Cephalexin is a preferred first-line antibiotic for the treatment of bacterial superinfections with S. aureus in children and adults with atopic dermatitis due to its restricted antimicrobial spectrum 7.
• Clindamycin is effective against community-associated MRSA (CA-MRSA) and is a suitable alternative to cephalexin for the treatment of uncomplicated pediatric skin infections 8.
• Vancomycin is effective against MRSA and is recommended for serious infections, but its use is limited due to concerns about resistance and nephrotoxicity 9.
• New antibiotics, such as linezolid, quinupristin/dalfopristin, and tedizolid, have good antistaphylococcal activity and may be reserved for patients who fail on or are intolerant of conventional therapy 9.

Considerations for Antibiotic Choice

• The choice of antibiotic should be based on the severity of the infection, the susceptibility of the causative organism, and the patient's medical history and allergies 6, 9.
• Close follow-up and fastidious wound care are likely more important than initial antibiotic choice for uncomplicated skin infections 8.
• The emergence of resistant and multidrug-resistant S. aureus strains highlights the need for careful antibiotic stewardship and the development of new antibiotics 9.