Boils
(Skin Abscesses)

Boils Slideshow

Medical Author: Melissa Conrad Stöppler, MD
Medical Editor: William C. Shiel Jr., MD, FACP, FACR

• What is a boil? What are the symptoms of a boil?
• What causes boils to form?
• Who is most likely to get a boil?
• What is the treatment for a boil?
• When should I seek medical attention?
• What can be done to prevent abscesses?
• Boils At A Glance
• Pictures of Boils - Slideshow
• Patient Discussions: Boils - Effective Treatments
• Find a local Dermatologist in your town

What is a boil? What are the symptoms of a boil?

A boil is a localized infection deep in the skin. A boil generally starts as a reddened, tender area. Over time, the area becomes firm and hard and tender. Eventually, the center of the abscess softens and becomes filled with infection-fighting white blood cells that the body sends from the bloodstream to eradicate the infection. This collection of white blood cells, bacteria, and proteins is known as pus. Finally, the pus "forms a head," which can be surgically opened or spontaneously drain out through the surface of the skin. A boil is also referred to as a skin abscess.

There are several different types of boils. Among these are:

• Furuncle or carbuncle: This is an abscess in the skin caused by the bacterium Staphylococcus aureus. A furuncle can have one or more openings onto the skin and may be associated with a fever or chills.



• Cystic acne: This is a type of abscess that is formed when oil ducts become clogged and infected. Cystic acne affects deeper skin tissue than the more superficial inflammation from common acne. Cystic acne is most common on the face and typically occurs in the teenage years.



• Hidradenitis suppurativa: This is a condition in which there are multiple abscesses that form under the armpits and often in the groin area. These areas are a result of local inflammation of the sweat glands. This form of skin infection is difficult to treat with antibiotics alone and typically requires a surgical procedure to remove the involved sweat glands in order to stop the skin inflammation.



• Pilonidal cyst: This is a unique kind of abscess that occurs in the crease of the buttocks. Pilonidal cysts often begin as tiny areas of infection in the base of the area of skin from which hair grows (the hair follicle). With irritation from direct pressure, over time the inflamed area enlarges to become a firm, painful, tender nodule that makes it difficult to sit without discomfort. These frequently form after long trips that involve prolonged sitting.

What causes boils to form?

There are many causes of boils. Some boils can be caused by an ingrown hair. Others can form as the result of a splinter or other foreign material that has become lodged in the skin. Others boils, such as those of acne, are caused by plugged sweat glands that become infected.

The skin is an essential part of our immune defense against materials and microbes that are foreign to our body. Any break in the skin, such as a cut or scrape, can develop into an abscess should it become infected with bacteria.

What does a boil look like?

Boils - Effective Treatments

The MedicineNet physician editors ask:

What kinds of treatments have been effective for your boils?

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