Gangrene
Gangrene is the death of tissue due to ischaemia. It can be divided into:
- dry gangrene = ischaemia only
- wet gangrene = ischaemia plus infection.
Treatment is debridement and antibiotics.
Necrotizing fasciitis
Necrotizing fasciitis is severe infection of the deep soft tissue, including fascia. 50% of patients have a skin injury prior to developing necrotizing fasciitis. Early presentation is erythema, swelling, and pain out of proportion to the presentation.
2 types
- Type 1: polymicrobial
- Type 2: group A streptococcus (strep pyogenes) and staphylococcus aureus
Treatment is surgical debridement and antibiotics
Mortality is around 25%
Fournier’s gangrene = Form of infective necrotising fasciitis of the perineal, genital or perianal regions
Increased risk in those with diabetes, alcoholism or other immunosupression
Meleney’s gangrene
= Form of gangrene that occurs postoperatively
Gas Gangrene
Gas gangrene is a necrotizing infection characterised by muscle necrosis, gas production and often septic shock. It is most commonly caused by clostridium perfringens, which is a gram negative rod. Most cases follow a contaminated traumatic injury (e.g. a farmer on a pitchfork) but occasionally cases can be spontaneous. Treatment is urgent surgical debridement and antibiotics.
Small print gem: Around 10% of patients with clostridial infections have an underlying malignancy.
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