What are the aims of this leaflet?

This leaflet has been written to help you understand more about boils (furuncles). It tells you what they are, what causes them, what can be done about them, and where you can find out more about them.

What are boils?

Hairs form under the surface of the skin in structures known as hair follicles. A boil is an infection (abscess) of the deep part of a hair follicle with a bacterium called Staphylococcus aureus (S. aureus). Multiple boils are known as a carbuncle. Occasionally, the infection may spread into the surrounding tissues (cellulitis), causing fever and illness.
S. aureuscan spread from one part of the body to another and from one person to another, via fingers, skin-to-skin contact, and contaminated clothing. Boils are most common in adolescents, and affect boys more often than girls. Sufferers of boils seldom have a problem with their immune system, although boils can be more severe when the immune system is suppressed.

What do boils look like?

A boil starts as a small itchy or tender spot that grows over a few days into a large red lump under the skin surface, becoming increasingly painful and tender. Boils inside the nose or ear can be particularly uncomfortable.
At this stage a boil may come to a head and eventually burst through the surface of the skin, releasing pus, or it may settle gradually without bursting. A healed boil tends to leave a red mark, which slowly fades but can leave a small scar. Boils may be single or multiple.

How are boils diagnosed?

Boils are usually straightforward to diagnose by their appearance. If a boil releases pus, this can be swabbed and sent to the laboratory to check which antibiotics are suitable to treat the boils, especially in cases where boils keep recurring.

Can boils be cured?

Yes. Infections caused by S. aureus settle with treatment. Sometimes severe or recurrent boils are caused by a type of bacteria called PVL staphylococcus which may need different antibiotics – please ask your doctor about this type of infection (see Patient Information Leaflet on PVL Staphylococcus Aureus (PVL-SA) skin infection).
The bacteria survive best in moist areas such as the nostrils, the armpits and the groin. Some people carry the S. aureusbacteria at these sites on a long-term basis. If repeated infection occurs, it is wise to treat these areas (see below).

How can boils be treated?

A single boil usually settles naturally, especially if the pus it contains discharges spontaneously. Sometimes your doctor may release the pus by cutting carefully into the boil (lancing it). This should only be done with sterile instruments once the boil has come to a head. An antibiotic cream or ointment can be used around the boil to stop others appearing nearby. Often an antibiotic is given by mouth as well, to make sure that the infection clears.

How do I stop the bacteria from spreading?

  • Your doctor will prescribe a topical treatment to wash yourself with and an antibacterial nasal ointment to be applied into each nostril; both of these are to be used for 5-7 days.
  • Family members may also have to use this treatment as well, if they are asymptomatic carriers.
  • You should also change towels every day and do not share them with anybody else. Use a hot wash and hot tumble dry if possible to wash towels and bed linen.
  • Change bed sheets daily.
  • Keep the house clean, especially the sink, shower or bath.

It is sensible to seek medical advice if you are not sure of the diagnosis, or if the treatment you have tried seems not to be helping. Recurrent boils may be caused by a toxin producing bacteria (PVL staphyloccus) or be a sign of underlying diabetes so see your doctor if the problem persists.

What can I do?

  • Follow the measures outlined above to reduce the spread of boils.
  • Bath or shower daily, and keep your hands and nails clean. Avoid picking any sores.
  • Being overweight encourages boils, as the bacteria survive in folds of the skin, therefore weight loss if necessary may help prevent recurrence.
  • Avoid close contact with others and contact sports, such as rugby and judo, until the boils have cleared to reduce the risk of passing the infection onto others. Do not visit a swimming pool or a gym until they have cleared up.

Where can I get more information?
Web links to detailed leaflets: