Cellulitis | Pokenga kiri

Cellulitis or pokenga kiri is an infection in the deeper layers of your skin. It’s usually caused by bacteria that are normally present on the surface of your skin but, if they get through your skin where it’s broken, they can multiply and cause cellulitis. The infected area becomes red, hot, swollen and tender to the touch.

Cellulitis generally only affects one side of the body. The area of skin affected by cellulitis becomes:

• red
• painful or tender to touch
• hot
• swollen.

It most often affects the lower legs but can occur on any part of your body including your face. Blisters may form and 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.

The image below shows cellulitis on a leg. The black marking is where the area of redness has been outlined to check if it changes size over time. You can read about this below.

Image credit: DermNet NZ

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.

A common cause of cellulitis is scratching your skin with dirty fingernails that carry bacteria. You’re more likely to get cellulitis if you have a skin condition that makes you itchy and more likely to scratch.

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.

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

The treatment for cellulitis is antibiotics.

• For mild cellulitis affecting a small area of skin, you'll be prescribed antibiotic pills (usually flucloxacillin).
• For moderate cellulitis you'll be given antibiotics (flucloxacillin or cefalexin) plus probenecid which helps the antibiotics stay in your system longer, making them more effective. 
• If it's more severe you may need intravenous (IV) antibiotics (into a vein). Your healthcare provider may arrange for you to have IV antibiotics without needing to go to hospital. As the infection improves, you may be able to change from intravenous to oral antibiotics, which can be taken at home for a further 7 to 10 days. Most people respond to antibiotics in 2 to 3 days and begin to show improvement.
• You may also be seen by a skin specialist (dermatologist), or by an eye specialist (ophthalmologist) if your cellulitis is near your eye.

Antibiotics

To help your body fight the infection, you will need 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're finished. It's important to do this even if the infection seems to have cleared up as there may be infection under the skin that you can’t see.

Note that the redness may continue to spread during the first 2 days of taking antibiotics. You should go back to your healthcare provider if the red area gets much bigger or you have a fever (high temperature). Cellulitis can spread to other parts of your body or to your blood. You may need blood tests and/or more antibiotics.

Your healthcare provider may mark the edge of the red area with a marker pen. Don't wash this off. This is so they can see if your skin infection is improving.

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. If you're not sure, talk to your healthcare provider to see if you need another course of antibiotics.

Pain relief

Cellulitis can be quite painful because it puts pressure on the skin from underneath. You can take pain relief medicines (eg, paracetamol) or an anti-inflammatory (eg, ibuprofen). Your healthcare provider will talk to you about appropriate pain relief and may give you a prescription. It’s also important to rest the affected area. The pain eases once the infection starts getting better.

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 healing.

If your healthcare provider decides you don’t need to see them every day, they will tell you how to look after your wound at home. If you have any concerns, ask your healthcare provider what to do.

Note that cellulitis doesn't cause pus. If you have pus coming from the wound you should tell your healthcare provider. There may be an abscess that needs to be drained for the infection to get better.

As well as taking antibiotics, you can:

• Get plenty of rest. This helps your body to fight the infection. If you have cellulitis on your leg, limit walking for the first few days.
• Raise the affected body part on a pillow or chair as much as possible, ideally above the level of your heart. If your arm or hand is involved, use a sling when you're walking around. This helps reduce swelling and inflammation and promotes healing. Continue to do this for the first 72 hours at least.
• Drink plenty of fluids to prevent dehydration.

Contact your healthcare provider again if your cellulitis is getting worse, you're feeling more unwell or if there's no improvement after 2 days on antibiotics.

Image credit: Canva

You can reduce the chances of getting cellulitis again by:

• keeping your 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 protective clothing and footwear
• keeping your finger nails short and avoiding scratching
• treating any breaks in your skin (eg, due to athlete’s foot or eczema)
• wearing gloves if you're working outside.

If you have diabetes or poor circulation you're at increased risk of cellulitis. It's important that you check your feet daily, moisturise your skin, trim your nails carefully and treat any infections on the skin (eg, athlete’s foot) quickly. 

If you've had cellulitis more than once within 6 months, you may be prescribed low-dose antibiotics long-term to stop the infection coming back.