Boils commonly develop because bacteria have infected hair follicles, which are the small openings that hair grows from.
Staphylococcus aureus ("staph") is the name of the bacteria that usually infect hair follicles. The bacteria normally live on the skin, particularly on certain parts of the body, such as the nose, mouth, genitals, and rectum. The bacteria cause an infection only if they enter the skin through a scrape, irritation, or injury of some kind. Sometimes friction on the skin--from clothing, for example--will cause a hair follicle to swell up. This can make the opening close up, trapping the bacteria inside and starting an infection.
Boils and carbuncles often form in moist areas of the body such as the back of the neck, buttocks, thighs, groin, and armpits.
If you have a chronic illness, such as diabetes or kidney or liver disease, you may be more likely to have boils and carbuncles.
A boil starts out as a red lump. Usually within 24 hours, the lump fills with pus and looks round with a yellow-white tip. Pus or other fluid may drain from the boil. There may be swelling around the boil. The boil may hurt only when you touch it or it may be quite painful all of the time.
Lymph nodes near the boil may also swell. You are most likely to notice swollen lymph nodes in the neck, armpit, or groin area.
Symptoms of carbuncles are similar but more severe than the symptoms caused by boils.
Your healthcare provider will examine the infected area. Tell your provider if you have had a boil or carbuncle longer than 2 weeks or if you have boils often.
If you have boils often, you may have lab tests of your blood or urine. These tests can check for conditions that might make you more likely to have the sores, such as diabetes or kidney or liver disease.
A boil can sometimes be treated at home, but a carbuncle often needs medical treatment.
For treatment at home you can:
These steps will help relieve the pain, reduce the risk of spreading the infection, and help boils to heal.
Your healthcare provider may recommend that you take antibiotic drugs to heal the infection. Your provider may drain the boil or carbuncle by opening it with a sterile needle or scalpel. After the sore has been opened, it should be covered with a loose, gauze dressing until it heals. Do not try to open a boil at home. Opening a boil at home may cause spread of the infection into the bloodstream and cause serious medical problems.
If you have an underlying illness, such as diabetes, your healthcare provider will want you to schedule follow-up appointments so your condition can be monitored. If your boil or carbuncle does not heal properly or if new symptoms develop, contact your provider.
Boils may take from 1 to 3 weeks to heal. In most cases, a boil will not heal until it opens and drains. This can take up to a week.
A carbuncle often requires treatment by your healthcare provider. Depending on the severity of the problem and its treatment, the carbuncle should heal in 2 to 3 weeks after treatment.
Your healthcare provider may want to see you for a follow-up visit if he or she prescribes medicine to treat the infection, such as antibiotics, or treats it by opening the boil.
Be sure to follow the instructions your healthcare provider gives you. Take any prescribed medicine as directed.
Call your healthcare provider if:
To help prevent boils and carbuncles from spreading and coming back:
Developed by RelayHealth.
Published by RelayHealth.
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
© 2010 RelayHealth and/or its affiliates. All Rights Reserved.