Severe soft tissue infection including suspected necrotising fasciitis and Fournier's gangrene

Antimicrobial prescribing: NHS Lothian
NHS Lothian

Clinical Features of Necrotising Fasciitis:

  • Septic shock.
  • Pain disproportionate to physical findings.
  • Anaesthesia over affected area.
  • Skin crepitation.
  • Skin necrosis or bullae.
  • Putrid discharge with thin 'dishwater' pus.

If the patient has none of these features, then necrotising fasciitis is unlikely. Follow guidance for: 

  • Cellulitis here
  • Sepsis in a person who injects drugs here
  • Human and animal bites here

Required Investigations

Early senior surgical review is crucial

DO NOT DELAY SURGICAL REVIEW OR SURGERY TO PERFORM CT SCAN

  • Blood cultures (10mls per bottle, before antibiotics are started)
  • Tissue samples from surgery should be sent for Gram stain & culture; contact microbiology to arrange urgent processing.

Initial antimicrobial recommendation

Recommended total duration:Depends on clinical response, and after discussion with an infection specialist

FIRST DOSE

Recommended Antibiotic

Piperacillin-tazobactam 4.5g IV

(PLUS Clindamycin 1200mg every 6 hours IV if evidence of toxic shock)
Penicillin allergy

Vancomycin IV (use NHS Lothian Calculator located on AMT intranet page) choose 15-20mg/L trough target

PLUS

Gentamicin IV (use NHS Lothian Calculator located on AMT intranet page)

PLUS

Metronidazole 500mg IV

(PLUS Clindamycin 1200mg IV if evidence of toxic shock)

IVIG is usually considered only in the critical care setting. 

  1. Call for help from:
    1. Senior clinical review (ST3+) and
    2. Urgent senior surgical review (ST3+) and
    3. Microbiology and
    4. Critical care.
  2. Where there is clinical uncertainty a senior infectious diseases review early can help clarify the clinical scenario.

Recommended ongoing treatment if necrotising skin soft tissue infection thought highly likely.

For necrotising skin/soft tissue infection

 

Recommended Antibiotic

Flucloxacillin 2g every 6 hours IV

PLUS

Gentamicin IV (use NHS Lothian Calculator located on AMT intranet page)

PLUS

Metronidazole 500mg every 8 hours IV

(PLUS Clindamycin 1200mg every 6 hours IV if evidence of toxic shock)
Penicillin allergy

Vancomycin IV (use NHS Lothian Calculator located on AMT intranet page) choose 15-20mg/L trough target

PLUS

Gentamicin IV (use NHS Lothian Calculator located on AMT intranet page)

PLUS

Metronidazole 500mg every 8 hours IV

(PLUS Clindamycin 1200mg every 6 hours IV if evidence of toxic shock)

IVIG is usually considered only in the critical care setting. 

For Fourniere’s gangrene (necrotising skin/soft tissue infection of perinuem/perianal region)

 

Recommended Antibiotic

Piperacillin-tazobactam 4.5g every 6 hours IV

PLUS

Gentamicin IV (use NHS Lothian Calculator located on AMT intranet page)

(PLUS Clindamycin 1200mg every 6 hours IV if evidence of toxic shock)
Penicillin allergy

Vancomycin IV (use NHS Lothian Calculator located on AMT intranet page) choose 15-20mg/L trough target

PLUS

Ciprofloxacin 400mg every 8 hours IV

PLUS

Metronidazole 500mg every 8 hours IV

(PLUS Clindamycin 1200mg every 6 hours IV if evidence of toxic shock)

IVIG is usually considered only in the critical care setting. 

Anthrax

Anthrax rarely occurs in Scotland and is usually associated with IV drug use.

Local signs include:

  • Marked local oedema
  • Severe local tissue damage 
  • A necrotic eschar. 

If Anthrax is possible/suspected, add ciprofloxacin 400mg IV every 12 hours to the above regimens if not already included.

For more details see HPS guidance here. 

Notes

Risk factors: diabetes mellitus, recent surgery, obesity, steroids.

Likely organisms:

  • Necrotising fasciitis can be mono-microbial: typically Group A Streptococcus (though sometimes other single organisms, e.g. other Streptococci, E.coli) OR poly-microbial: anaerobes, Gram negatives (E.coli), and Gram positives (Staph/Strep)
  • Upper Limb:S.aureus, Group AStreptococci
  • Lower Limb / abdomen / perineum (including Fournier’s Gangrene): polymicrobial, Gram negatives (E.coli), anaerobes, and Gram positives (Staph/Strep).