clinical features

Last edited 04/2020

Necrotising fasciitis can be seen in any part of the body, but it is more frequent in the exteremities, the perineum, and the truncal areas.

  • most commonly occurs at the perineum (36%), lower extremities (15.2%), postoperative wounds (14.7%), as well as in the abdomen, oral cavity, and neck (2)

There might be non-specific symptoms at the beginning of the disease which often results in a delayed diagnosis leading to septicaemia often accompanied by shcock or confusion (1).

  • often the initial focus of infection is a puncture wound, insect bite, scratch
  • usually begins like cellulitis with hot, red and tender skin, however, there may be an initial dissemination in the deeper tissue planes in the absence of surface changes
  • at the leading edge of infection, there is reddish or bronze discolouration of the skin and decreased sensation
  • the margin of infection advances rapidly along fascial planes
  • with thrombosis of perforating vessels, oedema, necrosis and sloughing of the skin occur
  • haemorrhagic bullae are relatively common
  • if this condition is untreated, toxaemia and death are the usual sequels

Clinical features:

Initial signs and symptoms include:

  • pain (1)           
  • fever (>38℃) -  often absent (in 44%)
  • tachycardia (>100 beats/min) - usually found  in 59%
  • erythem with ill defined margins
  • tenderness to palpitation
  • swelling
  • induration
  • lymphangitis is rare

As the disease progresses more advanced changes are observed:

  • severe pain
    • pain is usually out of proportion to visible skin changes
    • severe pain precedes skin changes by 24-48 h and is seen in in >97.8% of patients
  • tense oedema
  • skin anaesthesia
  • duskyblue/purple/black plaques that progress to haemorrhagic bullae and necrosis (4)
    • this classical text book picture may not occur untill day 5 or later (1)
  • crepitus
  • discharge of “dishwater” fluid
  • severe sepsis or systemic inflammatory response syndrome
  • multiorgan failure

Fournier's gangrene is one form of perineal or perianal necrotising soft tissue infection. It is described in the main menu. Commonly, it presents with scrotal swelling, pain, hyperemia, pruritus, crepitus, and fever. A foul smelling discharge may be seen in some patients  (5).

Images of necrotising fasciitis

Reference:

Related pages:

toxaemia

myositis (bacterial)

Fournier's scrotal gangrene

cellulitis

tachycardia

pyrexia

oedema

sepsis