Necrotizing soft tissue infection

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Necrotizing soft tissue infection is a rare but very severe type of bacterial infection. It can destroy the muscles, skin, and underlying tissue. The word "necrotizing" refers to something that causes body tissue to die.

Alternative Names

Necrotizing fasciitis; Fasciitis - necrotizing; Flesh-eating bacteria; Soft tissue gangrene; Gangrene - soft tissue


Many different types of bacteria can cause this infection. A very severe and usually deadly form of necrotizing soft tissue infection is due to the bacteria Streptococcus pyogenes, which is sometimes called "flesh-eating bacteria."

Necrotizing soft tissue infection develops when the bacteria enters the body, usually through a minor cut or scrape. The bacteria begins to grow and release harmful substances (toxins) that kill tissue and affect blood flow to the area. As the tissue dies, the bacteria enters the blood and rapidly spreads throughout the body.


Symptoms may include:

  • Small, red, painful lump or bump on the skin that spreads
  • A very painful bruise-like area then develops and grows rapidly, sometimes in less than an hour
  • The center becomes dark and dusky and then turns black and the tissue dies
  • The skin may break open and ooze fluid

Other symptoms may include:

  • Feeling ill
  • Fever
  • Sweating
  • Chills
  • Nausea
  • Dizziness
  • Weakness
  • Shock

Exams and Tests

The health care provider may be able to diagnose this condition by looking at your skin. Or, the condition may be diagnosed in an operating room by a surgeon.

Tests that may be done include:


Treatment is needed right away to prevent death. You'll likely need to stay in the hospital. Treatment includes:

  • Powerful antibiotics are given through a vein (IV)
  • Surgery to drain the sore and remove dead tissue
  • Special medicines called donor immunoglobulins (antibodies) to help fight the infection in some cases

Other treatments may include:

  • Skin grafts after the infection goes away to help your skin heal and look better
  • Amputation if the disease spreads through an arm or leg
  • 100% oxygen at high pressure (hyperbaric oxygen therapy) for certain types of bacterial infections

Outlook (Prognosis)

How well you do depends on:

  • Your overall health (especially if you have diabetes)
  • How fast you were diagnosed and how quickly you received treatment
  • The type of bacteria causing the infection
  • How quickly the infection spreads
  • How well treatment works

This disease commonly causes scarring and skin deformity.

Death can occur rapidly without proper treatment.

Possible Complications

Complications that may result from this condition include:

  • Infection spreads throughout body, causing a blood infection (sepsis), which can be deadly
  • Scarring and disfigurement
  • Loss of your ability to use an arm or leg
  • Death

When to Contact a Medical Professional

This disorder is severe and may be life-threatening. Contact your provider right away if symptoms of infection occur around a skin injury, including:

  • Drainage of pus or blood
  • Fever
  • Pain
  • Redness
  • Swelling


Always clean the skin thoroughly after a cut, scrape, or other skin injury.


Pallin DJ, Nassisi D. Skin and soft tissue infections. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 137.

Pasternack MS, Swartz MN. Cellulitis, necrotizing fasciitis, and subcutaneous tissue infections. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 95.

Stevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America. Clin Infect Dis. 2014;59(2):e10-52. PMID: 24973422

Version Info

  • Last reviewed on 10/9/2015
  • Kevin Berman, MD, PhD, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

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