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Necrotising fasciitis

Find out about necrotising fasciitis, including what the symptoms are, when to get medical help, how it's treated and what causes it.

About this information

This NHS content is written for people in England. Services, entitlements and contact routes may differ in other countries.

Symptoms of necrotising fasciitis

Symptoms of necrotising fasciitis can develop quickly within hours or over a few days.

The infection usually happens near a cut or wound, but sometimes there may be no obvious damage to your skin in the affected area.

At first you may have:

  • intense pain or loss of feeling – the pain may seem much worse than you would usually expect from a cut or wound, if there is one
  • redness and swelling of the skin around the affected area (redness may be harder to see on black or brown skin)
  • flu-like symptoms, such as a high temperature, headache and tiredness

Later symptoms can include:

  • being sick (vomiting) and diarrhoea
  • confusion
  • blisters or black, purple or grey blotches on the skin (blotches may be less obvious on black or brown skin)

Information

Necrotising fasciitis is very rare. The symptoms can be similar to more common skin infections like cellulitis.

Call 999 or go to A&E if:

  • you have a cut or wound, or red or swollen area of skin, that is much more painful than you would expect
  • you have a cut or wound, or red or swollen area of skin, and get symptoms like a high temperature, headache, tiredness and muscle aches
  • you have sudden confusion, feel dizzy, or feel like your heart is pounding, beating very fast, fluttering or missing a beat
  • you have black, purple or grey blotches or blisters near a cut or wound, or a red or swollen area of skin

Redness may be harder to see on black or brown skin.

Find your nearest A&E

A&E safety messaging

Do not drive to A&E. Ask someone to drive you or call 999 and ask for an ambulance.

Bring any medicines you take with you.

Treatments for necrotising fasciitis

Necrotising fasciitis gets worse quickly and can be fatal. It must be treated in hospital as soon as possible.

Treatment will usually include:

Even after successful treatment, there may be long-term changes in how your body looks and how you move or use the affected part of your body.

Sometimes amputation of affected limbs is needed.

You may need further surgery and physiotherapy to help you recover.

Causes of necrotising fasciitis

Necrotising fasciitis is an infection caused by bacteria getting into the deep layers of your skin.

The infection may get into your body through:

You may be more at risk from developing necrotising fasciitis if you have diabetes or a weakened immune system.

Necrotising fasciitis

Symptoms

Necrotising fasciitis

Medical treatments

Necrotising fasciitis

Causes

Symptoms of necrotising fasciitis include intense pain, swelling and dark blotches or blisters on the skin. You may also have flu-like symptoms.

You'll need emergency hospital treatment if you have necrotising fasciitis. The main treatments are antibiotics and surgery to remove the infection.

You can get necrotising fasciitis if bacteria get into the deep layers of your skin through a wound, such as a cut, burn or bite.

Content supplied by the NHS website

Content supplied by the NHS website, refreshed 19 August 2026. View the original NHS article ↗

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