SymptomsBy Mayo Clinic staff
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. Signs and symptoms of a boil usually include:
- A painful, red bump that starts out about the size of a pea
- Red, swollen skin around the bump
- An increase in the size of the bump over a few days as it fills with pus (can sometimes reach the size of a baseball)
- Development of a yellow-white tip that eventually ruptures and allows the pus to drain out
A carbuncle is a cluster of boils that form a connected area of infection. Carbuncles often occur on the back of the neck, shoulders or thighs. Compared with single boils, carbuncles cause a deeper and more severe infection and are more likely to leave a scar. People who have a carbuncle often feel unwell in general and may experience fever and chills.
When to see a doctor
You usually can care for a single, small boil yourself. But see your doctor if you have more than one boil at a time or if a boil:
- Occurs on your face
- Worsens rapidly or is extremely painful
- Causes a fever
- Is more than 2 inches (5 centimeters) across
- Hasn't healed in two weeks
- Habif TP. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 5th ed. Edinburgh, U.K.; New York, N.Y.: Mosby Elsevier; 2010. http://www.mdconsult.com/books/about.do?about=true&eid=4-u1.0-B978-0-7234-3541-9..X0001-6--TOP&isbn=978-0-7234-3541-9&uniqId=230100505-57. Accessed April 23, 2013.
- Goldsmith LA, et al., eds. Fitzpatrick's Dermatology in General Medicine. 8th ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://www.accessmedicine.com/resourceTOC.aspx?resourceID=740. Accessed April 23, 2013.
- Baddour LM. Skin abscesses, furuncles and carbuncles. http://www.uptodate.com/home. Accessed April 23, 2013.
- Rakel RE. Textbook of Family Medicine. 8th ed. Philadelphia, Pa.: Saunders Elsevier; 2011. http://www.mdconsult.com/das/book/body/191205553-4/0/1481/0.html#. Accessed April 23, 2013.
- Mandell GL, et al. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa.: Churchill Livingstone Elsevier; 2010. http://www.mdconsult.com/books/about.do?about=true&eid=4-u1.0-B978-0-443-06839-3..X0001-X--TOP&isbn=978-0-443-06839-3&uniqId=230100505-57. Accessed April 24, 2013.
- Steckelberg JM (expert opinion). Mayo Clinic, Rochester, Minn. May 2. 2013.
- Rohren CH (expert opinion). Mayo Clinic, Rochester, Minn. May 8, 2013.