The etiology of cellulitis has been thoroughly investigated and debated for decades. The use of different definitions for cellulitis is part of the problem, but the uncertain accuracy of methods such as serology and culture of skin biopsies have also been major obstacles for clarifying the cause of this common infection. We have hoped now that the modern molecular tools would bring us closer to the solution.

Most cases are treated with antibiotics at home, although sometimes hospital visits are necessary.

What’s on this page:

What is Cellulitis?

The condition is due to infection with bacteria, usually yellow staphylococci or streptococci. Rarely, other bacteria may form the basis of the infection. Cellulitis is an infection of the deeper layers of skin and underlying tissues. It can be serious if it is not treated quickly. Cellulitis must not be confused with cellulite (dimpled appearance of the skin that some people have on their hips, thighs and buttocks).

With Cellulitis will the skin in the face or lower part of the legs usually be affected, but cellulitis can also occur on other parts of the body. This infection can spread and lead to complications. In rare cases, the infection may cause blood poisoning – in the language of the pharmacy called sepsis. This is a very serious condition that affects the entire body and is caused by cellulitis not being treated in time or if antibiotics do not work.1

Why do you get Cellulitis?

Cellulitis occurs when certain types of bacteria pass through a cut or crack in the skin. Cellulitis is often caused by Staphylococcus and Streptococcus bacteria. Skin damage such as cuts, insect bites or surgical procedures are usually the infection sites. Some factors also increase the risk of developing cellulitis.

You can not be infected with cellulitis from another person as it affects the deeper layers of the skin.

Common risk factors include:

  • A weakened immune system
  • Skin conditions that cause skin damage, such as eczema
  • Intravenous (IV)
  • Use of needles
  • diabetes
  • A history of cellulitis


The infection develops suddenly and can spread rapidly through the body. Severe infections can spread deep into the body and be life-threatening. Symptoms of cellulitis develop suddenly and can get worse quickly. It affects the skin and can also cause more symptoms.

Cellulitis causes the affected skin to become:

  • Red
  • Warm
  • Swollen
  • Painful

Any part of the body can be affected, but the usual affected areas include the legs, feet, arms or hands, and sometimes the face, especially around the eyes.

Cellulitis can also cause additional symptoms that may develop before or next to changes in your skin.

These include:

  • Feeling generally unwell
  • Feeling sick
  • Trembling
  • Chills

Occasionally, the infection may spread to other parts of the body, such as deeper layers of the tissue, blood, muscle and bone. This can be very dangerous and potentially life-threatening.

Symptoms like the following can indicate that cellulitis is spreading:

  • Drowsiness
  • Apathy
  • Blisters
  • Red stripes in the skin

You should contact your doctor immediately if any of these symptoms occur.

The difference between cellulitis and rose (erysipelas)

Rose (erysipelas) is a bacterial skin infection characterised by a delimited skin area that is red, inflamed and sore. The infection is usually easily treated with antibiotics. Erysipelas and cellulitis make the skin red and sore. Erysipelas is often seen in the face, but may also occur elsewhere on the body. Cellulitis most often occurs on the legs or arms.

Cellulitis is an acute local infection of the skin that can spread. The spreading of infectious cellulitis can be severe, but with the quick and rapid treatment, you can get well and healthy. Cellulitis may remind a lot of the disease erysipelas (rose), but erysipelas is a much more superficial infection in the skin.

Antibiotics are effective on almost everyone with cellulitis or erysipelas. But you may need to start the antibiotic treatment intravenously in hospitals with cellulitis and switch to tablets when you get better. If the infection is mild you usually only need tablets.

When should I seek a help of a doctor?

There are some cases when this infection needs emergency treatment. If you experience any of the following symptoms, you must treat them quickly and get emergency medical attention:

  • The red or sore area goes numb
  • The red area becomes bigger or hardened
  • A black area that feels tender, hot and swollen
  • The pain gets worse
  • Vomiting or nausea
  • High fever or tremors

In addition, certain areas of the body are more sensitive than others, such as in or around the eyes. Children with facial cellulitis can sometimes develop brain infections. These are potentially very dangerous, so it should always be treated as an emergency.

Often, skin conditions cannot seem to be a potential emergency in the first place, but in the long run, they can be problematic and serious. As with all health problems, rapid treatment results in faster healing and fewer complications. It is always recommended to consult a doctor as soon as you suspect infection (any infection), instead of waiting to see if it can go over by itself.

Treatment options

It’s bacteria that are the cause of infectious cellulitis, they can easily be “killed” with the right antibiotics. Cellulitis is usually treated with dicloxacillin, which is in a tablet form taken for seven to ten days. In case of severe infection or no signs of improvement during the treatment, hospitalisation may be required for antibiotic treatment via intravenous. For fever and pain, you can use anti-inflammatory drugs (ibuprofen) and fever-reducing medicines (paracetamol), usually combined for better effect. With infectious cellulitis it is important to stay calm and rest and, if possible, to keep the area of infectious raised to dampen inflammation.


  1. More about the infection – NHS