Facts, Information and Advice.

Frequently Asked Questions.

Q:What is Necrotising Fasciitis (NF)? (back)

A: The term necrotising fasciitis comes from the words ‘necrosis’, which means death of a portion of tissue (flesh) and ‘fascia’, the name given to the sheets or bands of fibrous tissue which enclose and connect the muscles. NF is a severe infection involving the soft tissue below the skin, particularly the fascia. It can affect any part of the body but it is most common on the legs.

NF may be caused by a number of bacteria; one of these is Streptococcus pyogenes (also known as Strep. pyogenes or Group A streptococcus). Streptococcal necrotising fasciitis is a rare condition with approximately 1000 reported cases a year in this country.

Q: What is Strep.pyogenes ? (back)

A: Strep.pyogenes is a bacterium (germ) which can be found in the throat and sometimes the nose. It can also be carried on the skin. Children are more likely to be carriers than adults. Strep.pyogenes may also be found in the environment where it may persist for weeks in dust and on furnishings

Q: What infections does Strep.pyogenes cause ? (back)

A: The common infections caused by Strep.pyogenes are sore throats and skin infections, which are easily treated. Most types of Strep.pyogenes do not cause serious human infections, but a few types have this ability and can cause infections deep within the body including necrotising fasciitis. Many are accompanied by septicaemia (blood poisoning). All are serious, life-threatening and require urgent investigation and treatment. Despite this, the overall death rate is 25-40%.

In most half the cases, the source of the deep infection is never determined. Damage to the skin is the most common source of infection, for example, infection in minor cuts and grazes. Deep infections may also occur after surgery or childbirth. Patients with diseases such as diabetes, in which the blood supply to the tissues is poor, are most susceptible.

Q: How does NF occur ? (back)

A: NF arises most often spontaneously (without prior cause) in patients living in the community and often in previously perfect health. Cuts or grazes to the skin may be a source, but such damage may be trivial or may go unnoticed. Sometimes it may occur in hospitalised patients after surgery. When it arises in the community, the source is usually the patient’s own Strep pyogenes strain.

Recent investigations have suggested that patients taking painkillers of the type known as ‘Non-Steroidal Anti-Inflammatory Drugs’ (NSAIDs), may be slightly more at risk of NF. This has yet to be proved. Other risk factors include diabetes, age over 50 years, steroid treatment, high blood pressure, obesity and alcoholism. Strep. pyogenes also appears to have a particular liking for the skin spots of chicken pox, and NF may occasionally complicate this infection.

Q: What are the symptoms of NF ? (back)

A: NF may begin in an established wound (following either injury or surgery) or in broken skin such as a leg ulcer. Excessive pain is an early warning symptom. Bacteria spreads very rapidly in the tissues below the skin surface, well ahead of any visible changes in the overlying skin.

Infection may progress at inches per hour

The patient rapidly becomes generally unwell, with progressive deterioration out of all proportion to the visible changes in the skin of the affected area. If not treated very quickly, the skin over the infected are becomes dusky and purple; blisters may form and the skin dies. By this stage, infection may have penetrated deep into the underlying tissues. Patients often develop shock, with collapse, low blood pressure, and failure of liver, kidneys and other vital systems.

Q: What is the treatment for NF ? (back)

A: The key to patient survival is swift recognition and immediate treatment. Once recognised, high doses of antibiotics are required, but these on their own are insufficient to halt the infection with its severe local and general effects. The most important element of treatment is the surgical removal of the infected dead and dying tissue. If this is not done and done quickly, the infection continues to advance. Many patients who survive the first 48 hours need additional operations during and after this time to remove further infected tissue.

Q: What other measures are carried out ? (back)

A: Sometimes it may be necessary to check relatives or others in contact with the patient to see if they are carrying the same strain of Strep. pyogenes. This is normally done by taking nose and throat swabs. Occasionally other swabs may be advised. Contacts found to be carrying a Strep.pyogene strain may be treated with oral antibiotics.

Q: What is the outcome of NF ? (back)

A: Despite the best treatment, the infection is so severe that the death rate is still around 30-50%. Survivors may need amputation because of extensive areas of tissue being destroyed. NF can be severely disfiguring, and patients may need extensive plastic surgery and skin grafting to achieve the best possible functional and cosmetic result.