Necrotising Fasciitis

Question 1

Necrotising fasciitis is rare but very serious, can be life threatening, infection of the skin and underlying tissues, specifically the fascia. How common is this condition in the UK?

1 - 5/year
2 - 50/year
3 - 500/year
4 - 5000/year

Answer 1

4 - 5000/year

Question 2

What age does the incidence of necrotising fasciitis occur in?

1 - 15-30
2 - 25-40
3 - 30-50
4 - 50-60

Answer 2

4 - 50-60

Question 3

Is necrotising fasciitis dangerous?

Answer 3

• yes
• surgical emergency and can be life threatening

Question 4

What is the mortality rate of necrotising fasciitis?

1 - 1-2%
2 - 4-10%
3 - 20-25%
4 - >50%

Answer 4

3 - 20-25%

• sepsis is also common

Question 5

Which group of patients are most at risk?

1 - young children
2 - HIV patients
3 - diabetics
4 - cancer patients
5 - all of the above

Answer 5

5 - all of the above
- diabetes is the most common

• essentially any patient who is immunocompromised

Question 6

Necrotising fasciitis can affect anywhere on the body. All of the following are common places it can occur, but which is the most common location?

1 - feet
2 - lower legs
3 - hands
4 - genital areas

Answer 6

2 - lower legs

Question 7

Which layers of the skin are affected by necrotising fasciitis?

1 - epidermis
2 - dermis
3 - subcutaneous tissue
4 - muscle
5 - all of the above

Answer 7

5 - all of the above

Question 8

What is the name of Necrotising fasciitis if it occurs in the tongue?

1 - tonguitis
2 - fournier’s gangrene
3 - ludwig’s angina
4 - impetigo

Answer 8

3 - ludwig’s angina

Question 9

What is the name of Necrotising fasciitis if it occurs in the genitals?

1 - tonguitis
2 - fournier’s gangrene
3 - ludwig’s angina
4 - impetigo

Answer 9

2 - fournier’s gangrene

Question 10

Necrotising fasciitis is a very aggressive condition and spreads quickly. How is it able to spread so quickly?

1 - through blood
2 - uses lymphatics
3 - along soft tissue plains
4 - in hair follicles

Answer 10

3 - along soft tissue plains

• generally infects the deep fascia and then the subcutaneous layers

Question 11

Necrotising fasciitis is typically caused by a bacterial infection. What is the most common bacteria that cause necrotising fasciitis?

1 - E. coli
2 - Group A streptococcus
3 - Staphylococcus aureus
4 - Klebsiella

Answer 11

2 - Group A streptococcus

Question 12

In necrotising fasciitis the can be tissue death. What is the main action by which the bacteria are able to cause tissue death?

1 - eat tissue
2 - damage mitochondria
3 - release toxic substances into tissues
4 - body reduces blood flow to infected area

Answer 12

3 - release toxic substances into tissues

• toxins induce coagulation and clot formation
• clots blood blood vessels leading to tissue death

Question 13

In the first 24 hours of a patient having necrotising fasciitis, which of the following presentation may a patient present with?

1 - intense and severe pain out of proportion to external infection of skin
2 - break in the skin
3 - fever and flu like symptoms
4 - increased lactate and WCC
5 - all of the above

Answer 13

4 - all of the above

• can also occur in the absence of a break in the tissue
• air can become trapped under the skin and can present as crackling

Question 14

In the 3-4 days of a patient having necrotising fasciitis, which of the following presentation may a patient present with?

1 - swelling of the painful area
2 - rash in affected area
3 - diarrhoea and vomiting
4 - large dark blotches, that will turn into blisters and fill up with fluid (subcutaneous bullae)
5 - all of the above

Answer 14

5 - all of the above

Question 15

Which of the following are critical symptoms of necrotising fasciitis, which typically occurs in days 4-5 from infection?

1 - severe fall in blood pressure
2 - toxic shock from the poisons released by the bacteria
3 - unconsciousness as the body weakens
4 - all of the above

Answer 15

4 - all of the above

Question 16

Is imaging generally used to diagnose necrotising fasciitis?

Answer 16

• no as it delays surgery
• BUT may demonstrate subcutaneous gas or foreign body

Question 17

Which of the following is NOT a typical differential for necrotising fasciitis?

1 - folliculitis
2 - cellulitis
3 - erysipelas
4 - pyoderma gangrenosum

Answer 17

1 - folliculitis

Question 18

Which scoring system is used in necrotising fasciitis?

1 - Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC)
2 - modified Glasgow score
3 - CURB score
4 - Necrotising infection calculator

Answer 18

1 - Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC)

• raised WBC, CRP, creatinine
• low Na+ and Hb

BUT CLINICAL SUSPICION IS MORE IMPORTANT

Question 19

Necrotising fasciitis is a surgical emergency. What approach is generally taken?

1 - amputation
2 - remove infected skin and apply skin graft
3 - radical debridement to help healthy tissue bleed and IV antibiotics
4 - skin graft

Answer 19

3 - radical debridement to help healthy tissue bleed and IV antibiotics

• repeat debridement after 24-48h until infection is resolved
• fasciotomy if muscle is involved

Question 20

In addition to surgery for necrotising fasciitis, which of the following must also be performed?

1 - analgesia
2 - fluid resuscitation
3 - appropriate antibiotics (WHH = piperacillin-tazobactam + Clindamycin + Gentamicin)
4 -all of the above

Answer 20

4 - all of the above

• sample of tissue may be taken for culture to target antibiotics