Multiple species of bacteria can cause necrotizing fasciitis. This page focuses on type II necrotizing fasciitis where Streptococcus pyogenes is isolated alone or in combination with another species. Type II necrotizing fasciitis, known as hemolytic streptococcal gangrene, is characterized by isolation of S. Staphylococcus aureus is the most common species found in co-infection cases. Thus, these bacteria are also called group A Streptococcus or group A strep.
Streptococcal necrotizing fasciitis is a rare infection that typically occurs after trauma, sometimes minor or unapparent trauma, and surgery. Figure 1. Streptococcus pyogenes group A Streptococcus on Gram stain. Necrotizing fasciitis can affect any part of the body, but most commonly affects extremities, particularly the legs.
Necrotizing fasciitis begins with pain in the affected area accompanied by the following signs:. The pain experience by the patient is usually out of proportion to the signs of the local skin infection.
Swelling progresses to brawny edema and then to dark-red induration. Within 24 to 48 hours, the overlying skin may turn dusky, indicating small vessels in the dermal papilla have thrombosed. Affected tissues progressively darken from red to purple to blue to black.
Minus Related Pages. On This Page. Early symptoms of necrotizing fasciitis can include: A red, warm, or swollen area of skin that spreads quickly Severe pain, including pain beyond the area of the skin that is red, warm, or swollen Fever. Prompt Treatment Is Key. Diagnosis Can Be Difficult and Acting Fast Is Key There are many infections that look similar to necrotizing fasciitis in the early stages, which can make diagnosis difficult.
In addition to looking at the injury or infection, doctors can diagnose necrotizing fasciitis by: Taking a tissue sample biopsy Looking at bloodwork for signs of infection and muscle damage Imaging CT scan, MRI, ultrasound of the damaged area However, it is important to start treatment as soon as possible.
Use soap and water to clean all minor cuts and injuries. Related Pages. Top of Page. Related Links. Links with this icon indicate that you are leaving the CDC website. Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
You will be subject to the destination website's privacy policy when you follow the link. CDC is not responsible for Section compliance accessibility on other federal or private website. People who survive the infection are sometimes left with long-term disability as a result of amputation or the removal of a lot of infected tissue. They may also need further surgery to improve the appearance of the affected area and ongoing rehabilitation support to help them adapt to their disability. The bacteria lives in the gut, throat and, in some people, on the skin, where they do not usually cause any serious problems.
In rare cases, the bacteria can cause necrotising fasciitis if they get into deep tissue, either through the bloodstream or an injury or wound, such as:.
Necrotising fasciitis can also be a rare side effect of a type of diabetes medicine known as sodium-glucose co-transporter 2 SGLT2 inhibitors. Anyone can get necrotising fasciitis, including young and otherwise healthy people, but it tends to affect older people and those in poor general health.
If you're in close contact with someone who has necrotising fasciitis, you may be given a course of antibiotics to reduce your risk of infection. Necrotising fasciitis Necrotising fasciitis. A thorough history and clinical examination are crucial in arriving at the diagnosis of necrotising fasciitis.
Blood culture , deep tissue biopsy [see Necrotising fasciitis pathology ], and Gram stain help in identifying the culprit organism s and guide the choice of antibiotic. Blood cultures are usually negative for clostridial species. X-ray, CT scan, and MRI identify areas of fluid collection, inflammation and gas within the soft tissues. This test is not appropriate for all cases and is not completely reliable. Once the diagnosis of necrotising fasciitis is confirmed, treatment should be initiated without delay.
Immediate surgical debridement improves survival and avoids complications of necrotising fasciitis. All infected tissue should be cleared away using adequate excision. Repeated debridements are carried out for a few days. When the acute infection has subsided, the wound should be closed with skin grafting if required.
Vacuum-assisted wound closing devices may be useful to heal a persistent ulcer. Prompt diagnosis and treatment are essential to reduce the risk of death and disfigurement from necrotising fasciitis. If diagnosed and treated early, most patients will survive necrotising fasciitis with minimal scarring. If there is significant tissue loss, later skin grafting will be necessary and in some patients amputation of limbs is required to prevent death.
See smartphone apps to check your skin. Books about skin diseases Books about the skin Dermatology Made Easy book. DermNet NZ does not provide an online consultation service.
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