A boil (or furuncle) is a skin infection that is usually caused by the bacteria Staphylococcus aureus (staph). Other bacteria or fungi can also cause boils.
A boil forms a lump that goes deep into the skin. It may have a central “head” filled with pus. Boils usually occur on the face, neck, armpits, buttocks, and thighs, but can appear anywhere on the body. They can be painful.
In most boils, the bacteria also infect hair follicles, the sacs that contain the roots of hair and oil glands. An infection of the hair follicles is called folliculitis. A boil can also develop from a cut in the skin.
A carbuncle is a group of boils located in one area of the body. Carbuncles may have more than one head that fills with pus. Some people can get boils or carbuncles over and over in one spot of the body.
People with certain illnesses like diabetes are more likely to get boils. Another risk factor is having another skin condition such as eczema, or conditions that reduce the skin’s ability to fight germs.
This skin infection can be spread to other people. On rare occasions, it can be serious, and cause infection of the bloodstream, infection of other body parts, or general infection of the body (sepsis). A serious infection with MRSA (methicillin-resistant Staphylococcus aureus) can also occur.
What are the symptoms of a boil?
A boil may start out as a sore, raised area that is pinkish red in color. Over time, the boil may fill with clear liquid or pus, and grow in size.
Symptoms of a boil include the following:
- Swollen, red lump deep in the skin (Sometimes, a hair will grow from it.)
- Painful, especially when touched, and in certain places on the body (such as the nose or ear)
- Size can vary from pea to golf ball
- May develop a central, whitish-yellow “head” that may break and release pus
- May “weep” or ooze clear fluid, or develop a crust
- May spread to surrounding skin, creating a carbuncle
What are the symptoms of carbuncles?
Carbuncles cause a deeper and more serious infection than boils, so their symptoms may be more severe. In addition to the same symptoms as seen in boils, carbuncles may also:
- Cause fever and chills or other symptoms
- Heal more slowly
- Scar the skin
How is a boil or carbuncle treated?
A boil or carbuncle should never be squeezed or pricked with a pin or sharp object to release the pus and fluid. This can spread the infection to other parts of the skin.
If left alone, a boil will break and drain on its own over time. In certain cases, a doctor may need to cut into the skin to drain the pus. Once the fluid and pus drains from the boil or carbuncle, it will heal. The doctor may also prescribe antibiotics if there is a serious infection.
If you have a boil, you can do the following:
- Apply warm, moist compresses (such as a damp washcloth) several times a day. This can speed healing and relieve some of the pain and pressure caused by the boil. A separate washcloth (and towel) should be used.
- See a health care provider if the boil persists or comes back, or if it is located on the spine or on your face.
- If you have a fever or other serious symptoms with the boil, see your doctor. Patients who have diabetes or who have a condition that affects the immune system should see a doctor for the treatment of the boil.
How can I prevent a boil or carbuncle?
A boil or carbuncle can happen despite the best hygiene. However, you can prevent boils if you:
- Avoid close contact with someone who has a staph infection, boil, or carbuncle;
- Wash your hands frequently with antibacterial soaps and gels, which can help prevent the spread of bacteria;
- Bathe regularly with soap;
- Don’t share or re-use washcloths, towels, and sheets.
How can I keep my carbuncles from spreading to others?
If you have a carbuncle:
- Wash your hands often.
- Do not share washcloths and towels with family members.
- Don’t let others lie on your bed sheets.
- Use antibacterial soap, especially if you have touched your carbuncle.
- Do not squeeze or prick the head of your carbuncle.
- Do not hug or have close contact of your carbuncle with another person.
- Carefully bag and dispose of dressings and bandages that cover your carbuncle.
© Copyright 1995-2016 The Cleveland Clinic Foundation. All rights reserved.
This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 4/15/2016…#15153