necrotising fasciitis

Question 1

definition of necrotising fascitis

Answer 1

life threatening infection that spreads rapidly along fascial planes

rapidly progressibe infection of the deep fascia causing necrosis of subcut tissue

Question 2

aetiology of necrotising fasciitis

Answer 2

typically polymicrobial with streptococci, staphylococci, bacteroides and coliforms or clostridial forms

Question 3

risk factors for necrotising fasciitis

Answer 3

dm

PVD

leg ulcers

malignancy

immunosuppression

steroid

occaisionally occurs w/o obvious predisposing factor or in relation to puncture wounds, ulcers or surgical wounds

Question 4

epidemiology of necrotising fasciitis

Answer 4

rare

Question 5

sx of necrotising fasciitis

Answer 5

pain, often severe - out of proportion to the apparent physical signs

history of RF or predisposing event - eg trauma, ulcer, surgery

Question 6

signs of necrotising fascitis

Answer 6

area of erythema or oedema

areas of haemorrhagic blisters may be present, with crepitus on palpation

associated signs of systemic inflammatory response and sepsis - temp >38 or <36, tachycardia, tachypnoea, hypotension

Question 7

pathology of necrotising fasciitis

Answer 7

synergistic polymicrobial infection spreading along the SC and deep fascial planes

often caused by group A B-haemolytic Streptococcus pyogenes, or gram -ve and anaerobic synergistic infection eg enterococci, bacteroides

Question 8

what is fournier’s gangrene

Answer 8

necrotising fasciitis of the peritoneum

Question 9

ix for necrotising fasciitis

Answer 9

• bloods
  
  • FBC, UE< glucose, CRP, blood culture
• wound swab, pus/fluid aspirate
  
  • microscopy, gram stain, culture and sensitivity
• XR of affected area
  
  • may show gas in tissues formed by the organisms