Introduction 

Cellulitis is an infection of the deeper layers of the skin and the underlying tissue.

The main symptom of cellulitis is the affected area of skin suddenly turning red, painful swollen and hot.

It most often affects the legs, but can occur anywhere on the body.

When to see your GP

See your GP immediately if an area of skin suddenly turns red, hot and tender. If you can't see your GP on the same day, visit a walk-in centre or minor injuries unit.

Find a local walk-in centre or minor injuries unit using our service search.

Your GP can usually diagnose cellulitis by assessing your symptoms and examining your skin.

In some cases, further tests may be needed to rule out similar conditions, such as varicose eczema, or to assess the severity of the infection.

Hospital treatment

Certain symptoms can indicate that the infection has spread from your skin to other parts of the body, such as the blood. These include:

  • vomiting
  • fever
  • rapid breathing
  • confusion or disorientation

If you experience these severe symptoms, go to your local accident and emergency (A&E) department or call 999 for an ambulance.

Causes of cellulitis

Cellulitis can have a wide range of causes, but the majority of cases are caused by group A streptococcal infections or staphylococcal infections. In rarer cases, it may be caused by a fungal infection.

Cellulitis develops when bacteria or fungi move down through the skin’s surface through a damaged or broken area of skin, such as a cut, burn or bite.

Having a skin condition such as eczema or a fungal infection of the foot or toenails (athlete’s foot) can cause small breaks and cracks to develop in the surface of the skin. This makes a person more vulnerable to cellulitis.

Read about the causes of cellulitis, including more information on who is at risk.

Treating cellulitis

Cellulitis usually responds well to treatment with antibiotics if it's diagnosed and treated promptly.

As a precaution, hospital admission is usually recommended for more severe cases of cellulitis that fail to respond to antibiotic tablets. Once you have recovered you can usually be treated with antibiotics at home or as an outpatient.

Read more about treatment for cellulitis.

Complications

In some cases of cellulitis the bacteria triggers a secondary infection somewhere else in the body, such as in the blood (septicaemia).

Blood poisoning can be life-threatening and often requires hospital admission for treatment with intravenous antibiotics (antibiotics given directly into a vein).

Other complications can include:

  • abscesses
  • necrotising fasciitis – a rare bacterial infection of the deep layer of skin that causes the affected tissue to die
  • facial cellulitis – which can lead to meningitis if untreated

Read more about complications of cellulitis.

Who is affected?

Cellulitis can affect people of all ages, including children. Rates are thought to be roughly similar in both sexes.

In 2012, around 50,000 people were admitted to hospital in England as a result of cellulitis.




Cellulitis causes the affected area of skin to turn red, painful, hot and swollen 

The skin

The skin is the largest organ of the human body, made up of three main layers:

  • the epidermis – the outer surface of skin and an underlying section of cells, which the body uses to create new skin cells
  • dermis – the middle layer of skin that contains blood vessels, sweat glands and hair follicles
  • subcutis – the bottom layer of skin that consists of a layer of fat and collagen (a tough, spongy protein), which helps protect the body and regulate temperature

Cellulitis vs cellulite

Cellulite is a cosmetic problem caused by fatty deposits that form underneath the skin. It is not related to cellulitis.

Losing weight is the best way of dealing with cellulite. See the Live Well section of the website for information and advice about losing weight.

Page last reviewed: 15/08/2014

Next review due: 15/08/2016