Patient information from BMJ

Cellulitis and erysipelas

Last published:Jul 24, 2020

Cellulitis and erysipelas are bacterial skin infections. They cause the infected area to become red, inflamed, and sore. They're usually easy to cure with antibiotics.

What are cellulitis and erysipelas?

Cellulitis and erysipelas happen when germs called bacteria infect your skin. This can happen if you have a cut or scrape, an open sore (ulcer), a cut from surgery, or an insect bite.

Bacterial skin infections are also more likely to happen if you have a diabetic foot ulcer or if your immune system is weakened.

Cellulitis and erysipelas are so similar that doctors can't always tell them apart. The main difference is that cellulitis affects a deep layer of your skin. Erysipelas affects your skin nearer the surface. Both conditions are treated the same way.

It's important to get treatment for these infections as soon as possible so that they don't spread to other parts of your body. So if you have a painful rash it's best to see a doctor as soon as possible.

If you get cellulitis around your eye, you need to get treatment right away. The infection could spread and affect your eyes or your brain.

What are the symptoms?

Cellulitis and erysipelas make a patch of your skin turn red and feel sore. You're most likely to get cellulitis on your legs or arms, but it can appear anywhere. Erysipelas often affects the skin on the face.

The infection might spread over more of your skin, and the skin may blister. You may also get swollen glands near the infection, or feel generally ill, as if you have flu.

What treatments work?

Antibiotics cure cellulitis or erysipelas in most people who have the infection. They kill the bacteria that are causing the skin infection.

You may need to start antibiotic treatment in hospital with a drip (also called an intravenous infusion or IV). You'll switch to tablets when you start to get better. But if your cellulitis is mild you might just be given tablets.

You'll probably need to take the tablets for one or two weeks. Children may be able to take the antibiotics as a medicine or as chewable tablets.

As always with antibiotics, it's vital that you take them exactly as your doctor tells you to. Don't stop taking them if your rash goes away and you feel better, but finish all the tablets.

If you stop taking the pills part of the way through a course of antibiotics, some of the bacteria could survive. These bacteria are then much harder to kill if they cause another infection. Doctors call this 'antibiotic resistance' and it's a serious and growing problem that is making many diseases harder to treat.

Most people who take antibiotics will notice that their symptoms have cleared up after a week or so. But if your rash doesn't clear up, tell your doctor. You should have a follow-up appointment with your doctor, whatever happens.

If your infection is not clearing up you may need a different antibiotic or further tests. Or you might need to go to hospital to have more antibiotics by an IV drip.

Antibiotics can have side effects but they're usually mild. They include diarrhoea, nausea, abdomen pain, headaches, dizziness, and a rash.

You may be given a painkiller, such as paracetamol. This can make you more comfortable while you're waiting for the antibiotics to work.

If your cellulitis is on your leg or arm, you might be told to keep that limb higher than the rest of your body. This is called elevation, and it can help the swelling go down. If your skin starts to blister you may be given a dressing to put on it.

What will happen to me?

With treatment, most people who have cellulitis or erysipelas recover completely in about two weeks. If you're usually healthy you may be treated at home. But some people need hospital treatment. You may be able to go home after a day or two if you're feeling better.

Sometimes cellulitis can spread and cause other problems (complications). These include blood poisoning (sepsis), which is a severe infection that affects your whole body. This is rare, but it may happen if the cellulitis isn't treated in time or if the antibiotics don't work.

Cellulitis can also come back. Your doctor should advise you about things you can do to help prevent further skin infections, such as making sure you keep cuts and scrapes clean, and keeping patches of dry skin moisturised.

Some people get swelling in the arm or leg where they get cellulitis. This is called lymphoedema. Treatment usually gets rid of the inflamed patch of skin, but in some people the swelling doesn't go away.