From the Guidelines
For treating skin infections caused by Methicillin-Sensitive Staphylococcus Aureus (MSSA), dicloxacillin or cephalexin is recommended as a 7-day regimen, as these isolates are usually methicillin susceptible 1. When considering treatment options for skin MSSA infections, it's essential to note that the Infectious Diseases Society of America recommends oral therapy with an agent active against S. aureus unless cultures yield streptococci alone 1.
- Key considerations for treatment include:
- Severity of the infection: Mild to moderate infections can be treated with oral antibiotics, while more severe infections may require alternative approaches.
- Culture results: If cultures yield streptococci alone, oral penicillin is the recommended agent 1.
- Suspected or confirmed MRSA: In such cases, doxycycline, clindamycin, or sulfamethoxazole-trimethoprim (SMX-TMP) is recommended 1. In addition to antibiotics, proper wound care is crucial, including keeping the area clean and applying topical mupirocin 2% ointment if necessary 1.
- It's also important to note that:
- Patients should complete the full course of antibiotics to prevent recurrence and antibiotic resistance.
- MSSA responds well to beta-lactam antibiotics, making penicillin derivatives and cephalosporins highly effective against this pathogen. Given the evidence, dicloxacillin or cephalexin for 7 days is the recommended treatment for skin MSSA infections, as stated in the guidelines by the Infectious Diseases Society of America 1.
From the FDA Drug Label
The penicillinase-resistant penicillins are indicated in the treatment of infections caused by penicillinase-producing staphylococci which have demonstrated susceptibility to the drugs. Cultures and susceptibility tests should be performed initially to determine the causative organism and their sensitivity to the drug The penicillinase-resistant penicillins may be used to initiate therapy in suspected cases of resistant staphylococcal infections prior to the availability of laboratory test results.
Skin MSSA treatment can be done with dicloxacillin, a penicillinase-resistant penicillin, as it is indicated for the treatment of infections caused by penicillinase-producing staphylococci, including MSSA (Methicillin-Susceptible Staphylococcus aureus).
- The treatment should be based on the results of cultures and susceptibility tests.
- Dicloxacillin should only be used to treat bacterial infections that are proven or strongly suspected to be caused by susceptible bacteria 2.
- It is essential to take the entire course of therapy as prescribed, even if symptoms have stopped, to ensure the infection is fully treated and to reduce the development of drug-resistant bacteria 2.
From the Research
Treatment Options for Skin MSSA Infections
- Penicillinase-resistant penicillins (flucloxacillin, dicloxacillin) are the antibiotics of choice for the management of serious methicillin-susceptible S. aureus (MSSA) infections 3
- First generation cephalosporins (cefazolin, cephalothin and cephalexin), clindamycin, lincomycin and erythromycin have important therapeutic roles in less serious MSSA infections such as skin and soft tissue infections or in patients with penicillin hypersensitivity 3
- Cefazolin is not significantly different from cloxacillin in the treatment of MSSA bacteraemia, while treatment with other beta-lactams, including second and third generation cephalosporins, might be associated with higher mortality 4
Comparison of Treatment Outcomes
- Patients with mecA-MSSA bloodstream infections may be at higher risk for poor clinical outcomes, including clinical failure and persistent bacteremia, compared to MRSA BSI patients 5
- Treatment with cefazolin or cloxacillin is associated with lower 30-day mortality in patients with MSSA bacteraemia, compared to treatment with other beta-lactams 4
Alternative Treatment Options
- Minocycline is reliably effective in the treatment of uncomplicated community-acquired MRSA skin and soft-tissue infections, especially when doxycycline or trimethoprim-sulfamethoxazole fails 6
- New antibiotics such as linezolid and quinupristin/dalfopristin have good antistaphylococcal activity, but are very expensive and should be reserved for patients who fail on or are intolerant of conventional therapy or who have highly resistant strains 3