Cellulitis

What is cellulitis?

Cellulitis is an infection of the skin and the tissues beneath it. It has nothing to do with the cosmetic problem cellulite.

Cellulitis causes

Cellulitis is usually caused by bacteria, most commonly of the streptococci or staphylococci groups, which normally live on the skin's surface. Damage to the skin (a spot, scratch or larger wound) allows bacteria to enter the deeper tissues and establish an infection.

However, any bacteria can cause cellulitis, and the initial damage to the skin may be so minor as to go unnoticed. Some people are more vulnerable to cellulitis, or more likely to get complications, especially those with diabetes, or those whose immune system isn't working well.

Cellulitis symptoms

Symptoms of cellulitis include:

• Hot, red, swollen and painful area of the skin and deeper tissues
• Fever
• Shivers and chills, caused by release of toxins from the bacteria

There may be a well-defined line where the cellulitis stops, but this may spread as the infection progresses. Rarely, there's oozing of pus and fluid at the skin puncture site, but usually the infection is more diffuse in the tissues.

Cellulitis complications

Sometimes a cellulitis infection can be trapped by certain 'compartments' in the tissues, for example, around a muscle or ligament, or in the 'pulp' at the tip of a finger. The pressure in that compartment increases, cutting off the blood supply (which may cause gangrene) and damaging nerves. This needs urgent treatment and decompression.

Another complication is blood poisoning or sepsis, when bacteria get into the bloodstream. This can be rapidly fatal and needs very urgent treatment.

Cellulitis treatments

Fortunately, cellulitis usually responds well to antibiotics. Ideally, the skin and wound should be swabbed to test the kind of bacteria causing the problem, then a penicillin type of antibiotic is usually needed (or erythromycin for those who are allergic to penicillin).

In some cases, wound swabs or blood tests indicate a different bacterial cause and other types of antibiotic may be needed. Sometimes intravenous antibiotics are needed and this may mean a stay in hospital. A long course of treatment (usually up to two weeks but sometimes for several months) may be necessary. If pus collects within the affected area, an operation may be needed to drain it.

Cellulitis can be prevented by being careful about hygiene with wounds and breaks in the skin. If you cut or scratch yourself, or break the skin in some way, make sure the wound is cleaned and treated with an antiseptic, then covered with a clean dressing or plaster. If the skin around the wound becomes red and sore, get medical advice as soon as possible.