Aetiology of necrotising skin and soft tissue infections

Necrotising skin and soft tissue infections can be monomicrobial or polymicrobial.

Pathogens to consider for monomicrobial necrotising skin and soft tissue infections include:

• streptococci (especially Streptococcus pyogenes [group A streptococcus])
• Clostridium perfringens and other Clostridium species
• Staphylococcus aureus
• Vibrio vulnificus and other Vibrio species
• Aeromonas hydrophila.

Clostridial myonecrosis, also known as gas gangrene, is a monomicrobial infection.

Types of polymicrobial necrotising skin and soft tissue infections include:

• synergistic gangrene – infection involves mixed aerobe–anaerobe bacteria (eg Escherichia coli, Bacteroides fragilis, streptococci and staphylococci)
• Fournier gangrene – synergistic gangrene of the genitalia, usually following genital trauma (eg postpartum) or spread from a perianal, retroperitoneal or urinary tract infection
• necrotising infection of the head and neck – generally polymicrobial and can occur in the setting of odontogenic infection or following oropharyngeal surgery or traumaGunaratne, 2018.