Cellulitis

(you say, sell-you-ly-tis)

Cellulitis is an infection that affects the deeper layers of the skin. It needs treatment with antibiotics as it can be serious if not treated quickly. Anybody can get cellulitis. Once you’ve had it, you are more likely to get it again in the same part of your body.

Key points

  1. Areas of skin affected by cellulitis become red, painful, hot and swollen.
  2. See a doctor (preferably today) if the affected area is bigger than a 10 cent piece.
  3. Early treatment with antibiotics can stop the infection from becoming more serious.
  4. Go back to the doctor if the red area gets much bigger or deeper or if you have a fever. Cellulitis can spread to other parts of your body or to your blood. You may need blood tests and/or more antibiotics.
  5. You can reduce the chances of getting cellulitis again by keeping skin clean and well moisturised and treating any breaks in your skin.

What are the signs of cellulitis?

Areas of skin affected by cellulitis become red, painful, hot and swollen. Blisters may form. The affected area may grow larger. This can happen quite quickly, over hours to a few days.

You may also feel unwell and feverish with a high temperature and shivers. This may start a few hours or a day before the skin changes become visible.

When to seek medical help 

See a doctor (preferably today) if the affected area is bigger than a 10 cent piece.

Ask for an urgent GP appointment (straight away) if: 

  • your face or the area around your eye is affected
  • the affected area grows rapidly and/or is extremely painful
  • you develop a fever or flu-like symptoms
  • you have a weakened immune system – for example, because of chemotherapy or diabetes
  • a young child or elderly person has possible cellulitis.

Early treatment with antibiotics can stop the infection becoming more serious.


What causes cellulitis?

Cellulitis is usually caused by a bacterial infection. The bacteria are usually present on your skin without causing infection, but if they get through your skin (eg, through cuts, bites or dry, cracked skin), they can multiply and cause cellulitis. Sometimes the break in the skin is too small to notice.

Once the bacteria are in the skin, they cause redness and swelling that can spread rapidly.

You can't catch cellulitis from another person as it affects the deeper layers of the skin.

Who is at risk of cellulitis?

Anybody can get cellulitis. Some of the common things that make you more at risk of getting cellulitis are:

  • having had cellulitis before
  • having poor circulation in your arms, legs, hands or feet
  • difficulty moving around
  • being overweight
  • having a weakened immune system (ie, caused by uncontrolled diabetes or chemotherapy)
  • having a skin condition (ie, eczema, psoriasis, scabies or acne)
  • having athlete's foot (fungal infection of the skin between the toe webs)
  • having chronic swelling (lymphoedema, heart failure)
  • injecting drugs
  • having a wound from surgery
  • having had an insect or animal bite.

How is cellulitis treated?

For mild cellulitis affecting a small area of skin, your GP will prescribe oral antibiotics (taken by mouth). In more severe cases, you need to go to hospital for intravenous antibiotics (injected).

Taking antibiotics

Make sure you understand how to take the antibiotics – how many times per day and what dose. Take the antibiotics every day until they are finished. Do this even if the infection seems to have cleared up. The antibiotics need to keep killing the infection in your body after the skin has healed.

Your doctor may mark the edge of the red area with a marker pen. Do not wash this off. This is so your doctor can see if your skin infection is improving.

Go back to the doctor if the red area gets much bigger or deeper or you have a fever. Cellulitis can spread to other parts of the body or to the blood. You may need blood tests and/or more antibiotics.

Most people make a full recovery after 7 to 10 days. If your symptoms are improving, you can stop taking antibiotics at the end of the prescribed course. Do this even if you still have some skin changes as these can take a long time to completely go away, even when the infection has been treated. If uncertain, talk to your doctor.

Wound care

If you have a wound, it needs to be kept clean and covered with a dressing. Your wound should be checked every day. This may be by a nurse or an Accident and Medical centre team. They will change the dressing and check that the wound is improving.

If your nurse or doctor decides you don’t need to see them every day, they will tell you how to look after your wound at home. If there is anything of concern, ask your doctor what to do.

Note that cellulitis does not cause pus. If you have pus coming from the wound you should tell your doctor. There may be an abscess that needs to be drained in order for the infection to get better.

Things you can do yourself

As well as taking antibiotics, to support your recovery you can do the following:

  • Get plenty of rest. This helps your body to fight the infection.
  • Raise the affected body part on a pillow or chair when you're sitting or lying down. This helps reduce swelling.
  • If your arm or hand is involved, use the sling provided when walking around. This not only helps relieve pain but also helps the healing process.
  • Regularly but gently move the joint near the affected body part, such as your wrist or ankle, to stop it getting stiff.
  • Drink plenty of water to prevent dehydration.
  • Cellulitis can be quite painful because it presses the skin out. Your GP will discuss if it is safe to use paracetamol or other pain relief medications. Do not use ibuprofen unless advised by your GP.

What can I do to stop cellulitis recurring?

You can reduce the chances of getting cellulitis again by:

  • keeping skin clean and well moisturised – dry skin causes cracks which increase your risk of cellulitis
  • cleaning any cuts or wounds.
  • preventing cuts and scrapes by wearing appropriate clothing and footwear.
  • treating any breaks in the skin, eg, due to athlete’s foot or eczema – your doctor may prescribe a medicated cream for this.
  • wearing gloves if working outside.

Some people with recurring cellulitis might be prescribed low-dose long-term antibiotics to stop infections coming back.

Cellulitis complications

If not treated quickly, the infection can spread to other parts of the body, such as the blood, muscles and bones.

Call 111 or go to A&E now if you have cellulitis with:

  • a very high temperature or you feel hot and shivery
  • a fast heartbeat or fast breathing
  • purple patches on your skin
  • confusion, dizziness or disorientation
  • cold, clammy, pale skin
  • unresponsiveness or loss of consciousness

These are symptoms of sepsis, which can be very serious and potentially life-threatening.

Learn more

Cellulitis: skin deep and spreading across New Zealand BPAC, NZ, 2015
Antibiotics: choices for common infections – cellulitis BPAC NZ, 2017
Cellulitis Kidshealth, NZ
Cellulitis NHS Choices, UK
Cellulitis Mayo Clinic, US

Credits: Health Navigator Editorial Team, Image source: Jama Patient Page. Reviewed By: Dr Christopher Luey, Infectious Diseases Consultant, CMDHB Last reviewed: 28 Feb 2019