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Necrotizing fasciitis pathology أبريل 2019 - Coggle Diagram
Necrotizing fasciitis pathology
أبريل 2019
Def.
Severe and life-threatening bacterial infection that affects the deep layers of the skin, including the fascia, muscles, and surrounding tissues. It is commonly referred to as a "flesh-eating" infection because it rapidly destroys the affected tissues.
Epidemiology:
A rare condition but can occur worldwide. It affects all ages, but more commonly in adults.
Predisposing factors :
Immunocompromised states (such as diabetes, cancer, or HIV),
obesity,
IV drug use,
chronic alcoholism,
and recent surgical procedures.
Etiology:
The commonest is bacterial infection by
Group A Streptococcus (GAS) and
(MRSA).
Other bacteria, as Klebsiella, Clostridium, E. coli, and other Strept. species, can be implicated.
Site:
Most commonly affects the extremities, particularly the lower limbs.
It can also occur in the abdomen, perineum, or other areas with a break in the skin integrity.
Gross Picture:
Rapidly progressing inflammation and destruction of the affected tissues.
The affected area appears swollen, erythematous , and may exhibit blistering or ulceration.
The infection involves the deep fascia, subcutaneous tissues, and underlying muscles.
As the infection progresses, the tissue become necrotic, appearing black or dark in color.
Microscopic Picture:
Extensive tissue necrosis and inflammation.
The histopathological findings typically show coagulative necrosis, infiltration of inflammatory cells, thrombosis of blood vessels, and the presence of bacteria within the affected tissues.
Spread
Spread rapidly along the fascial planes and involve adjacent tissues. The infection can extend both longitudinally and circumferentially, leading to the destruction of large areas of tissue.
In severe cases, the infection can spread systemically through the bloodstream, causing sepsis and affecting multiple organ systems.
Complications:
Sepsis,
organ failure (renal, respiratory failure),
(DIC),
Toxic shock syndrome,
Compartment syndrome,
Gangrene
Prognosis:
The prognosis of necrotizing fasciitis depends on various factors, including the promptness of diagnosis, the extent of tissue involvement, the underlying health status of the individual, and the effectiveness of treatment.
Early recognition and aggressive surgical debridement, along with appropriate antibiotic therapy, are crucial for improving outcomes.
However, necrotizing fasciitis remains a life-threatening condition, and mortality rates can range from 20% to over 50%.
Causes of Death:
Severe sepsis,
Multiple organ failure,
Systemic complications resulting from the rapid and extensive tissue destruction.
Delayed diagnosis,
Inadequate surgical debridement, or
Ineffective antibiotic therapy.