Necrotizing fasciitis is a subset of aggressive skin and soft tissue infections (SSTIs) that cause necrosis of the muscle fascia and subcutaneous tissues. The infection typically travels along the fascial plane, which has a poor blood supply.

1. Necrotizing Fasciitis
Zubair Abbasi
2020/058
CG-A

2. Learning objectives
 Definition
 Causes
 Types
 Clinical features
 Diagnosis
 Treatment
 Complications

3. Definition
 Necrotizing fasciitis (NF) is a rare infection that means
“decaying infection of the fascia,” which is the soft tissue
that is part of the connective tissue system that runs
throughout the body. NF is caused by one or more bacteria
that attacks the skin, the tissue just beneath the skin
(subcutaneous tissue) and the fascia causing these tissues
to die (necrosis).

4. Causes of NF
 Bacterial Infection: Necrotizing Fasciitis is primarily caused by
certain types of bacteria, most commonly Streptococcus pyogenes
(group A streptococcus) and Staphylococcus aureus. Other bacteria
such as Clostridium species can also cause this condition.
 Entry Through Skin Breaks: The bacteria typically enter the body
through a break in the skin, such as a cut, scrape, surgical incision,
puncture wound, or insect bite. Even minor injuries that might not
seem serious can provide an entry point for the bacteria.
 Compromised Immune System: Individuals with weakened immune
systems, such as those with diabetes, chronic illnesses, cancer, or
immunodeficiency disorders, are at higher risk of developing
Necrotizing Fasciitis.

5.  Risk Factors: Certain risk factors increase the likelihood of developing
Necrotizing Fasciitis, including obesity, intravenous drug use, chronic
alcoholism, peripheral vascular disease, and malnutrition. These
factors can impair the body's ability to fight off infections and
contribute to tissue damage.
 Transmission: Necrotizing Fasciitis is not contagious from person to
person like a cold or flu. It occurs when bacteria already present on
the skin or in the environment enter the body through a wound or
injury.

6. Types of NF

7. TYPE ORGANISM CHARACTERISTICS
TYPE 1 Polymicrobial
Typically 4-5 aerobic and
anaerobic species cultured:
Non-Group A Strep
Anaerobes including
Clostridia
Facultative anaerobes
Enterobacteria
Most common (80-90%)
Seen in immunosuppressed
(diabetics and cancer
patients)
Postop abdominal and
perineal infections
TYPE 2 Monomicrobial
Group A β-hemolytic
Streptococci is most
common organism isolated
5% of cases
Seen in healthy patients
Extremities
TYPE 3 Marine Vibrio vulnificus
(gram negative rods)
Marine exposure
TYPE 4 Fungal

8. Clinical features
 Severe Pain: Patients often experience severe pain in the affected
area, typically disproportionate to the visible signs of infection.
 Swelling and Redness: The affected area may appear swollen, red,
and warm to the touch. The skin may also become discolored, ranging
from red to purple or black.
 Fever and Chills: Patients may develop a fever and experience chills
as the body responds to the infection.
 Skin Changes: The skin over the affected area may rapidly develop
blisters, ulcers, or areas of necrosis (tissue death). These changes may
progress quickly, sometimes within hours.

10.  Systemic Symptoms: As the infection spreads, patients may
experience systemic symptoms such as malaise, fatigue, nausea, and
vomiting.
 Rapid Progression: Necrotizing fasciitis can progress rapidly, with the
infection spreading along the facial planes and causing extensive
tissue damage in a short period.
 Crepitus: In some cases, gas produced by the bacteria may
accumulate under the skin, leading to a characteristic crackling
sensation (crepitus) when the affected area is palpated.
 Hypotension and Shock: In severe cases, necrotizing fasciitis can lead
to systemic inflammation, sepsis, hypotension, and shock, which can
be life-threatening if not promptly treated.

12. Diagnosis
 Laboratory Tests:
 Blood tests are conducted to evaluate markers of inflammation (such as
C-reactive protein and white blood cell count) and assess for signs of
systemic infection (such as elevated lactate levels).
 Blood cultures may be taken to identify the causative bacteria.
 Imaging Studies:
 Imaging studies such as X-rays, ultrasound, computed tomography (CT)
scans, or magnetic resonance imaging (MRI) may be performed to assess
the extent of tissue involvement, identify areas of gas formation (which
can indicate severe infection), and aid in surgical planning.
 Surgical Exploration:
 In some cases, surgical exploration and tissue biopsy may be necessary to confirm
the diagnosis. During surgery, the surgeon can directly visualize the affected
tissue, assess its viability, and obtain tissue samples for culture and
histopathological examination.

13. Extensive soft tissue gas involving the right
hand and visualized right forearm.

14. Laboratory Risk Indicator for Necrotizing Fasciitis
(LRINEC) score
A LRINEC score of ≥6 should raise the suspicion of
necrotizing fasciitis, and a score of ≥8 is strongly
predictive of this disease.

15. Treatment
 Surgical:
 Prompt surgical intervention is the cornerstone of treatment for
necrotizing fasciitis. Surgical debridement involves the removal of
necrotic (dead) tissue and infected material to halt the spread of the
infection.
 In severe cases, amputation of affected limbs or surgical interventions to
control hemorrhage may be necessary.
 Broad-Spectrum Antibiotics:
 Empirical broad-spectrum antibiotics are initiated immediately upon
suspicion of necrotizing fasciitis and are adjusted based on culture and
sensitivity results.
 Antibiotics are typically administered intravenously to achieve high tissue
concentrations. Coverage often includes antibiotics effective against
common causative organisms such as Streptococcus pyogenes,
Staphylococcus aureus (including methicillin-resistant strains), and
anaerobic bacteria.

16.  Supportive Care:
 Supportive measures may include intravenous fluids, electrolyte
replacement, and nutritional support to maintain the patient's
overall health and prevent complications such as dehydration and
malnutrition.
 Patients may require monitoring in an intensive care unit (ICU) for
hemodynamic stability and close observation for signs of systemic
inflammation and organ dysfunction.
 Pain Management:
 Adequate pain management is essential, given the severe pain
associated with necrotizing fasciitis. Analgesics, including opioids,
may be used to alleviate pain and improve patient comfort.
 Monitoring and Follow-up:
 Patients require close monitoring during treatment to assess
response to therapy, monitor for complications, and ensure wound
healing.
 Long-term follow-up may be necessary to address potential
complications such as chronic pain, functional impairment, and
psychological sequelae.

17. Complication
 It can also result in life-long complications from
 loss of limbs or
 severe scarring due to surgically removing infected
tissue.
 Looking at data from the most recent five years: Even
with treatment, up to 1 in 5 people with necrotizing
fasciitis died from the infection.

19. References
 https://www.tamingthesru.com/blog/2018/9/3/necrotizing-fasciitis-
and-the-spectrum-of-soft-tissue-infections
 https://radiopaedia.org/articles/necrotising-fasciitis
 https://www.icliniq.com/articles/infectious-diseases/necrotizing-
fasciitis
 https://www.orthobullets.com/trauma/1007/necrotizing-fasciitis

20. Thank you