A boil is a tender red lump on your skin that is caused by an infection of a hair root or sweat pore. Large boils can form abscesses.
- The most common places for boils to appear are on your face, neck, armpits, shoulders and buttocks (bottom).
- Boils are not usually a serious problem. However, if the infection spreads, you must see your doctor (GP).
- Small boils can be treated at home with warm compresses but larger boils and abscesses will usually need to be treated by your GP.
- Boils can spread very easily so it is important to practice good hygiene.
- If you keep getting boils, you need to reduce the source of bacteria causing the reinfection.
What causes boils and abscesses?
Boils are usually caused by a bacteria called Staphylococcus aureus, which often lives harmlessly on human skin. However, any break in your skin barrier leaves it vulnerable to infection and can lead to the development of a boil.
Large boils can form abscesses, which is the build up of pus within an area. A cluster of boils that have multiple white pus heads is called a carbuncle.
Who is at risk of getting boils?
Anyone can develop a boil. Most people with boils are otherwise healthy. The following conditions can increase your risk of getting boils:
- diabetes and other illnesses that weaken your immune system
- broken skin such as cuts and grazes, which allow bacteria to enter your body
- anaemia or iron deficiency
- some medicines – if you think any medicines you are taking might be causing boils, ask your pharmacist.
How are boils and abscesses treated?
Small boils can be treated at home. Larger boils and abscesses will usually need to be treated by your GP.
Small boils can be treated at home with warm compresses to encourage the boil to open and drain naturally.
You can make a warm compress by wetting a facecloth with warm (not hot) water and putting it on the boil for several minutes. Do this a few times a day. Do this as soon as you notice a boil. The heat and moisture can help the boil to open and drain, which usually takes a few days.
Always wash your hands before and after touching the boil.
Practice good hygiene to stop the boil spreading
Boils can spread very easily. If the boil opens on its own and drains, wipe away the pus or blood with a clean cotton ball soaked in antiseptic solution (such as Savlon or Dettol – follow the directions on the bottle for making the solution). Wash and dry the area well and then cover it with a plaster. This stops the boil from spreading.
Wash your hands with soap and dry thoroughly before and after touching the boil. Also wash your body with warm soapy water or use an antiseptic solution such as Savlon or Dettol.
To help keep the infection from spreading:
- use your own towel and facecloth – don't share them
- wash your towel and facecloth often in hot water along with any clothing worn close to your skin
- don't squeeze, scratch, drain or open the boil – squeezing can push the infection deeper into your skin
- don't pop the boil with a needle – this could make the infection worse.
Larger boils and abscesses
Larger boils and abscesses can be treated with incision (a cut) and drainage. This means that your GP will cut a small opening in the boil so that the pus can drain out. This is also called lancing the boil. Sometimes gauze is placed in the cut so that it stays open and keeps draining.
If you have fever, cellulitis (an infection that affects the deeper layers of your skin) or other conditions such as diabetes, an oral antibiotic may also be prescribed.
Referral to hospital for surgical drainage is more common for children or adults with complicated or large boils.
When should I see my doctor for a boil?
You should see your GP if:
- you have a boil on your face, nose or spine – this can sometimes cause serious complications
- the boil does not form a head or point or does not get better within a week
- you have lots of pain or discomfort
- you get a fever
- the boil has red streaks coming from it
- the boil is the size of a 10 cent coin or larger or the boil keeps getting bigger
- you have several boils
- your have diabetes or a weakened immune system.
How are recurrent boils treated?
Some people get boils repeatedly because they carry a strain of bacteria that easily causes infection of any broken skin (minor cuts and scrapes). In this case, you need to reduce any source of bacteria causing reinfection.
- Use an antiseptic body wash for a week to get rid of bacteria on your skin.
- Treat new boils or lesions straight away.
- Keep boils covered with plaster to reduce spreading infection to other parts of your body or to other family members.
- Sheets, towels and clothes should be washed in hot water to reduce reinfection.
- Some people may be asked to apply an antibiotic cream to your nose (where the bacteria are often carried).
- You may be asked to have dilute bleach baths twice a week. Read more about bleach baths.
Boils DermNet NZ
Boils in children KidsHealth, NZ
Bleach baths DermNet NZ
|Dr Li-Wern Yim is a travel doctor with a background in general practice. She studied medicine at the University of Otago, and has a postgraduate diploma in travel medicine (Otago). She also studied tropical medicine in Uganda and Tanzania, and holds a diploma from the London School of Hygiene & Tropical Medicine. She currently works in clinical travel medicine in Auckland.