What antibiotic is used to treat skin infections (bacterial infections of the skin)?

From the Guidelines

For skin infections, the most effective antibiotic regimen is cephalexin (Keflex) 500mg four times daily for 7-10 days or clindamycin 300mg four times daily for 7-10 days, as recommended by the Infectious Diseases Society of America guidelines 1.

Key Considerations

• These antibiotics effectively target Staphylococcus aureus and Streptococcus species, which are the most common bacteria causing skin infections.
• For suspected MRSA (methicillin-resistant Staphylococcus aureus), trimethoprim-sulfamethoxazole (Bactrim) 1-2 double-strength tablets twice daily for 7-10 days or doxycycline 100mg twice daily for 7-10 days may be more appropriate, as suggested by the 2018 WSES/SIS-E consensus conference 1.
• It's essential to complete the full course of antibiotics even if symptoms improve before finishing, to ensure the infection is fully cleared and reduce the risk of antibiotic resistance.
• Keeping the infected area clean by washing with mild soap and water, and covering with a clean bandage if there's drainage, can help promote healing and prevent the spread of infection.
• If the infection worsens despite antibiotics (increasing redness, swelling, pain, fever), seek immediate medical attention as this could indicate a need for intravenous antibiotics or surgical drainage, as recommended by the Infectious Diseases Society of America guidelines 1.

Additional Recommendations

• For patients with severe or extensive disease, vancomycin or another antimicrobial effective against both MRSA and streptococci may be recommended, as suggested by the Infectious Diseases Society of America guidelines 1.
• The recommended duration of antimicrobial therapy is 5-14 days, but should be individualized based on the patient's clinical response, as recommended by the 2018 WSES/SIS-E consensus conference 1.
• IV to oral switch should occur when criteria of clinical stability have been reached, as recommended by the 2018 WSES/SIS-E consensus conference 1.

From the FDA Drug Label

For the following infections, a dosage of 500 mg may be administered every 12 hours: streptococcal pharyngitis, skin and skin structure infections, and uncomplicated cystitis in patients over 15 years of age. In severe infections, the dosage may be doubled. Serious skin and soft tissue infections; septicemia; intra- abdominal infections such as peritonitis and intra-abdominal abscess

Cephalexin and clindamycin can be used to treat skin infections.

• The recommended dosage of cephalexin for skin and skin structure infections is 500 mg every 12 hours 2.
• Clindamycin is indicated for serious skin and soft tissue infections 3. It is essential to consider the severity of the infection, the causative organisms, and their susceptibility to the antibiotic when selecting a treatment option.

From the Research

Antibiotic Options for Skin Infections

• Cephalexin is an effective antibiotic for the treatment of streptococcal and staphylococcal skin infections, with cure rates of 90% or higher 4.
• It is comparable to other antibiotics such as erythromycin, clindamycin, dicloxacillin, and cloxacillin in the treatment of these infections 4.
• Penicillin remains the drug of choice for streptococcal skin infections, but cephalexin and other alternative antibiotics may become more important in the primary treatment of mixed streptococcal-staphylococcal lesions if cure rates with penicillin continue to decrease 4.

Comparison of Cefdinir and Cephalexin

• A study comparing cefdinir and cephalexin for mild to moderate uncomplicated skin and skin structure infections found that both antibiotics had similar clinical cure rates, with 89% of patients achieving clinical cure in both treatment groups 5.
• Cefdinir was more highly rated than cephalexin in a composite usefulness assessment, primarily due to the convenience of taking the medication 5.
• Both antibiotics were well tolerated, with the most common treatment-related adverse events being diarrhea, nausea, and vaginal mycosis 5.

Treatment of Specific Infections

• Cephalexin is effective against methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) infections, with clinical cure rates of 93% and 92% respectively 5.
• Cefdinir also demonstrated high clinical cure rates against MSSA and MRSA infections, with rates of 93% and 92% respectively 5.
• However, the clinical response rates against MRSA infections must be interpreted with caution, as cephalosporins do not have accepted, clinically relevant in vitro activity against MRSA 5.