MRSA un-complicated soft tissue infection - Management of Infection Guidance for Primary Care

Publication: 30/09/2010  
Next review: 31/12/2021  
Clinical Guideline
ID: 2258 
Approved By:  
Copyright© Leeds Teaching Hospitals NHS Trust 2018  


This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

MRSA uncomplicated skin and soft tissue infection treatment in Primary Care in adults

Skin and soft tissue are the most common presentation of MRSA infection, although it can also cause invasive, severe disease. This guideline is for treatment of uncomplicated skin and soft tissue infection.(eg cellulitis, eryipalis, abscess) with MRSA.
It is not applicable to patients with evidence of systemic illness (such as sepsis), necrotising /deep tissue infections, superficial infections (such as pustules and papules), hidradenitis suppurativa, or immunocompromising conditions.

  • Minor skin and soft tissue infections (SSTIs) (furunculosis, folliculitis, small boils without cellulitis) do not need systemic antibiotic treatment.
  • Non-severe/uncomplicated cellulitis with no systemic illness may be treated with oral antibiotics
    • Consider the need for IV antibiotics/admission for assessment if risk factors for treatment failure/poor outcome (cellulitis affecting face or perineum, frail/aged >80 , previous splenectomy, chronic renal or liver disease, immunocompromised, alcohol abuse, treatment failure in the community, diabetes mellitus, chronic venous insufficiency, morbid obesity).
  • Abscesses - Incision and drainage is the optimal management for abscesses.     
  • larger abscesses (especially those > 5cm) should be treated with oral antibiotics in addition to drainage.
  • small abscesses - consider additional use of antibiotics - discuss potential benefits and side-effects with the patient (see notes below).

 If active infection, with MRSA confirmed by lab results, and admission not warranted:

  • Use sensitivities on report to guide treatment;
  • If no response, seek advice from microbiologist.

If active infection and patient has MRSA risk factors (see below), and admission not warranted:

  • MRSA should be considered when choosing empirical (best guess) antimicrobial treatment regimens for infection;
  • The treatment options below are suitable empirical treatment for uncomplicated SSTI where MRSA is suspected - confirm sensitivities with cultures and adjust antibiotic treatment accordingly.

Risk factors for MRSA infection include:

  • patients who are/have been colonised with MRSA (from screening swabs);
  • patients who have had previous MRSA infections;
  • being a resident of a long term care facility (nursing home, residential home or any other long term residential facility)
  • patients who have recently been in hospital;
prior antibiotic use, particularly cephalosporins and fluoroquinolones.

 Preferred Option

Alternative Option


Doxycycline 100mg twice daily PO 5 days (may be extended up to 14 days depending on clinical response).

Co-trimoxazole (trimethoprim/sulfamethoxazole) 960mg twice daily PO 5 days (may be extended up to 14 days depending on clinical response).


Clindamycin 300 - 450mg qds PO 5 days (may be extended up to 14 days depending on clinical response).

Check the MRSA is susceptible - see culture sensitivity report.

Doxycycline contraindicated in pregnancy.

Co-trimoxazole may slightly increase the risk of congenital malformations, including neural tube defects, when prescribed to pregnant women

Clindamycin is considered safe in pregnancy but has a higher risk of diarrhoea


Approximately 1/3 people carry Staphylococcus aureus on their skin/nasal passages. About 10% of these will be MRSA (methicillin-resistant Staph. aureus). MRSA is resistant to penicillin-related antibiotics such as flucloxacillin and most cephalosporins, and may be resistant to other antibiotic classes.
Antibiotics are not indicated for MRSA colonisation. A topical decolonisation regime may be indicated (decolonisation should be administered according to local screening and decolonisation protocols).
Identifying the infecting pathogen may not be necessary for treating uncomplicated skin abscesses, but cultures may be helpful in patients with recurrent abscesses or where there is lack of response to empiric antibiotics.The most common pathogens are Staphylococcus aureus, most often methicillin-resistant (MRSA), and several other bacteria, most originating from the skin flora.
Recurrent skin infections may be due to Panton-Valentine Leukocidin - Staphylococcus aureus (PVL-SA), which may be MRSA or MSSA: consider testing for PVL-SA. Decolonization may be indicated for recurrent/persistent PVL-SA skin infections and should be discussed with community Infection Prevention & Control team or microbiologist.
Community outbreaks of MRSA infections have been reported in multiple settings, including sports teams, childcare centres, and prisons.

Consideration of additional antibiotics to incision and drainage for minor skin abscesses:

A recent BMJ Rapid Recommendation team produced a clinical practice guideline based on a systematic review of randomised controlled trials (RCTs) on the effects of adjuvant antibiotic therapy compared with no antibiotic therapy in addition to incision and drainage in patients with uncomplicated skin abscesses. (Wang W et al. Antibiotics for uncomplicated skin abscesses: systematic review and network meta-analysis. BMJ Open2018;8:e020991).

This systemic review was carried out following the publication of a placebo controlled study that suggested that, for small uncomplicated skin abscesses, the addition of clindamycin or trimethoprim-sulfamethoxazole (co-trimoxazole) after incision and drainage improved the chance of short term cure compared with placebo, but the benefit was restricted to those with S. aureus infection.

A large RCT published in March 2016 suggested that co-trimoxazole treatment resulted in a higher cure rate than placebo among patients with a drained cutaneous abscess in settings in which MRSA was prevalent.

A previous systematic review of the treatment of uncomplicated skin and soft tissue abscesses (SSTAs) after incision and drainage found no clear evidence of a benefit for the addition of antibiotics for treating uncomplicated SSTAs.

Wang et al concluded that, in patients with uncomplicated skin abscesses, moderate-to-high quality evidence suggests co-trimoxazole or clindamycin confer a modest benefit for several important outcomes, but this is offset by a similar risk of adverse effects. Clindamycin has a substantially higher risk of diarrhoea than co-trimoxazole. Cephalosporins are probably not effective.

The BMJ clinical practice guideline makes a weak recommendation in favour of using co-trimoxazole or clindamycin in addition to incision and drainage over incision and drainage alone. For patients who have chosen to initiate antibiotics, the panel issued a strong recommendation for co-trimoxazole or clindamycin rather than a cephalosporin and a weak recommendation for co-trimoxazole rather than clindamycin.The panel emphasised shared decision making in the choice of whether to initiate antibiotics and in which antibiotic to use, because the desirable and undesirable consequences are closely balanced.

Compared with no antibiotics, co-trimoxazole or clindamycin reduced the absolute risk of treatment failure by approximately 5% at one month (high quality evidence). In patients who were cured, these antibiotics reduced the absolute risk of recurrence at three months by approximately 8% (high quality evidence). When considering both treatment failure and abscess recurrence, antibiotic therapy thus provided an approximate 13% reduction (high quality evidence). Co-trimoxazole or clindamycin probably provides a modest reduction in pain (tenderness) during treatment (7% fewer), and a small reduction in hospitalisation (2% fewer) and in similar infections among household contacts (2% fewer) (all moderate quality evidence). The panel commented that antibiotics may confer an even smaller benefit in patients who present to their GP rather than ED. Antibiotics probably do not reduce the risk of serious or invasive infections or death (moderate quality evidence). Overall, there is no important difference in treatment failure between co-trimoxazole and clindamycin (high quality evidence). In patients who were initially cured, one study suggested that clindamycin may reduce the risk of early recurrence at one month by approximately 7% (low quality evidence), but the confidence interval was wide and this result is inconsistent with indirect evidence from other RCTs, which suggests that the reduction in risk of abscess recurrence compared with placebo is similar for both co-trimoxazole and clindamycin. Whether clindamycin reduces abscess recurrence more than co-trimoxazole is therefore uncertain (low quality evidence).

The occurrence of adverse effects depends on the antibiotic. With clindamycin, the risk of gastrointestinal side effects (predominately diarrhoea) is approximately 10% higher than with no antibiotics (high quality evidence). Clindamycin has a 10% higher risk of antibiotic-associated diarrhoea than co-trimoxazole (high quality evidence).

Co-trimoxazole probably increases the risk of gastrointestinal side effects by a smaller amount (approximately 2%; moderate quality evidence), and it is predominately nausea rather than diarrhoea. The severity of antibiotic-associated diarrhoea was not described, but is likely to range from mild to severe. Two large trials monitored for Clostridium difficile infection with routine clinical monitoring and no such infection occurred in any treatment arm.

The panel is confident that the evidence applies to almost all patients with uncomplicated skin abscesses treated with incision and drainage: adults and children, patients presenting to emergency departments and to primary care practices, smaller and larger abscesses, first abscess occurrences and recurrences, and abscesses with unknown infection pathogens.

The recommendations explicitly take a person-centred perspective rather than a public health or societal perspective. The use of antibiotics is associated with the emergence of antibiotic resistance within the community and may increase the risk of antibiotic resistant infections in community members. The increasing rates of antimicrobial resistance are a public health priority. From a societal perspective, it is possible that the modest benefits from adjuvant antibiotics in this scenario would not outweigh the risk of increased antimicrobial resistance in the community. However, the impact of an individual course of antibiotics on community resistance rates is unknown. Therefore, whether antibiotics in this situation provide a net benefit or harm to society is highly speculative. Clinicians engaging in shared decision making can also address the issue of antibiotic resistance or the local prevalence of other pathogens (such as Panton-Valentine leukocidin (PVL) positive Staphylococcus aureus) with patients facing this decision.

General Principles for Treating Infections  

This summary table is based on the best available evidence, but use professional judgement and involve patients in management decisions.

  1. This summary table should not be used in isolation; it should be supported with patient information about safety netting, back-up antibiotics, self-care, infection severity and usual duration, clinical staff education, and audits. Materials are available on the RCGP TARGET website.

  2. Prescribe an antibiotic only when there is likely to be clear clinical benefit, giving alternative, non-antibiotic self-care advice, where appropriate.

  3. If person is systemically unwell with symptoms or signs of serious illness, or is at high risk of complications: give immediate antibiotic. Always consider possibility of sepsis, and refer to hospital if severe systemic infection

  4. Use a lower threshold for antibiotics in immunocompromised, or in those with multiple morbidities; consider culture/specimens, and seek advice.

  5. In severe infection, or immunocompromised, it is important to initiate antibiotics as soon as possible, particularly if sepsis is suspected. If patient is not at moderate to high risk for sepsis, give information about symptom monitoring, and how to access medical care if they are concerned.

  6. Where an empirical therapy has failed or special circumstances exist, microbiological advice can be obtained from LTHT Microbiology (Mon-Fri 9am-5pm and Sat and Sun 9am-1pm: 0113 39 23962/28580; Otherwise via LTHT switchboard - ask for the On call Microbiology Registrar)

  7. Limit prescribing over the telephone to exceptional cases.

  8. Use simple, generic antibiotics if possible. Avoid broad spectrum antibiotics (for example coamoxiclav, quinolones and cephalosporins) when narrow spectrum antibiotics remain effective, as they increase the risk of Clostridium difficile, MRSA and resistant UTIs.

  9. Avoid widespread use of topical antibiotics, especially in those agents also available systemically (for example fusidic acid); in most cases, topical use should be limited.

  10. Always check for antibiotic allergies. A dose and duration of treatment for adults is usually suggested, but may need modification for age, weight, renal function, or if immunocompromised. In severe or recurrent cases, consider a larger dose or longer course.

  11. Avoid use of quinolones unless benefits outweigh the risk as new 2018 evidence indicates that they may be rarely associated with long lasting disabling neuro-muscular and skeletal side effects.
  12. Refer to the BNF for further dosing and interaction information (for example the interaction between macrolides and statins), and check for hypersensitivity.


Note: Doses are oral and for adults unless otherwise stated. Please refer to BNF for further information.
Letters indicate strength of evidence:
A+ = systematic review: D = expert opinion


Record: 2258
Clinical condition:

MRSA un-complicated soft tissue infection

Target patient group:
Target professional group(s): Primary Care Doctors
Adapted from:

Evidence base

Grading of guidance recommendations
The strength of each recommendation is qualified by a letter in parenthesis.

Study design


Good recent systematic review and meta-analysis of studies


One or more rigorous studies; randomised controlled trials


One or more prospective studies


One or more retrospective studies


Non-analytic studies, eg case reports or case series


Formal combination of expert opinion


Daum RS, Miller LG, Immergluck L, et al. A Placebo-Controlled Trial of Antibiotics for Smaller Skin Abscesses. The New England journal of medicine 2017; 376(26): 2545-55.

Fahimi J, Singh A, Frazee BW. The role of adjunctive antibiotics in the treatment of skin and soft tissue abscesses: a systematic review and meta-analysis. CJEM 2015; 17(4): 420-32.

Talan et al., Trimethoprim-sulfamethoxazole versus placebo for uncomplicated skin abscess. N Engl J Med2016;374:823-32.doi:doi:10.1056/NEJMoa1507476.pmid:26962903

Wang W et al. Antibiotics for uncomplicated skin abscesses: systematic review and network meta-analysis. BMJ Open 2018;8:e020991


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