Boils

Boils are painful, pus-filled bumps that form under your skin when bacteria infect and inflame one or more of your hair follicles.

What is it?

Boils usually start as red, tender lumps. The lumps quickly fill with pus, growing larger and more painful until they rupture and drain. Although some boils disappear a few days after they occur, most take about two weeks to heal.

Boils can occur anywhere on your skin, but appear mainly on your face, neck, armpits, buttocks or thighs — hair-bearing areas where you're most likely to sweat or experience friction. Sometimes boils occur in clusters called carbuncles. Although anyone can develop boils and carbuncles, people who have diabetes, a suppressed immune system, or acne or other skin problems are at increased risk.

You can usually care for a single boil at home, but don't attempt to lance or squeeze it — that may spread the infection. Call your doctor if a boil or carbuncle is extremely painful, lasts longer than two weeks or occurs with a fever. In that case, you may need antibiotics or surgical drainage to clear the infection of boils and carbuncles.

What causes it?

Boils usually form when one or more hair follicles — the tube-shaped shafts from which hair grows — become infected with staph bacteria (Staphylococcus aureus). These bacteria, which normally inhabit your skin and sometimes your throat and nasal passages, are responsible for a number of serious diseases, including pneumonia, meningitis, urinary tract infections and endocarditis — an infection of the lining of your heart. They're also a major cause of hospital-acquired infections and food-borne illnesses.

Staph bacteria that cause boils generally enter through a cut, scratch or other break in your skin. As soon as this occurs, specialized white blood cells called neutrophils rush to the site to fight the infection. This leads to inflammation and eventually to the formation of pus — a mixture of old white blood cells, bacteria and dead skin cells.

What are the symptoms?

A boil usually appears suddenly as a painful pink or red bump that's generally not more than 1 inch in diameter. The surrounding skin also may be red and swollen.

Within a few days, the bump fills with pus. It grows larger and more painful for about five to seven days, sometimes reaching golf ball size before it develops a yellow-white tip that finally ruptures and drains. Boils generally clear completely in about two weeks. Small boils usually heal without scarring, but a large boil may leave a scar.

Are there any natural therapies?

Tea tree oil, which is extracted from the leaves of the Australian tea tree (Melaleuca alternifolia), has been used for centuries as an antiseptic, antibiotic and antifungal agent. It may help relieve discomfort and speed healing.

For best results, apply the oil to a boil several times a day. The oil can cause allergic reactions in some people, so be sure to stop using it if you have any problems.

What else can I do?

Although it's not always possible to prevent boils, especially if you have a compromised immune system, the following measures may help you avoid staph infections:

• Thoroughly clean even small cuts and scrapes. Wash well with soap and water and apply an over-the-counter antibiotic ointment.

• Avoid constricting clothing. Tight clothes may be stylish, but make sure they don't chafe your skin.

Did you know?

Although anyone – including otherwise healthy people – can develop boils, the following factors can increase your risk:

• Poor general health
• Diabetes
• Clothing that binds or chafes
• Other skin condition
• Immune-suppressing medication.