What is Carbuncle

A carbuncle is a red, swollen, and painful cluster of boils that are connected to each other under the skin. A boil (or furuncle) is an infection of a hair follicle that has a small collection of pus (called an abscess) under the skin. Usually single, a carbuncle is most likely to occur on a hairy area of the body such as the back or nape of the neck. But a carbuncle also can develop in other areas of the body such as the buttocks, thighs, groin, and armpits.

Carbuncles are painful clusters of boils that are contagious. Is also an abscess larger than a boil, usually with one or more openings draining pus onto the skin. It is usually caused by bacterial infections that often involves a group of hair follicles. The infected material forms a lump, which occurs deep in the skin and may contain pus.


Most carbuncles are caused by Staphylococcus aureus bacteria, which inhabit the skin surface, throat, and nasal passages. These bacteria can cause infection by entering the skin through a hair follicle, small scrape, or puncture, although sometimes there is no obvious point of entry.

Filled with pus - a mixture of old and white blood cells, bacteria, and dead skin cells - carbuncles must drain before they're able to heal. Carbuncles are more likely than boils to leave scars.

An active boil or carbuncle is contagious: the infection can spread to other parts of the person's body or to other people through skin-to-skin contact or the sharing of personal items. So it's important to practice appropriate self-care measures, like keeping the area clean and covered, until the carbuncle drains and heals.


Carbuncles require medical treatment to prevent or manage complications, promote healing, and minimize scarring. Contact your doctor if you have a boil or boils that have persisted for more than a few days.

Risk Factors for Carbuncles

Older age, obesity, poor hygiene, and poor overall health are associated with carbuncles. Other risk factors for carbuncles include:
  • Chronic skin conditions, which damage the skin's protective barrier
  • Diabetes
  • Kidney disease
  • Liver disease
  • Any condition or treatment that weakens the immune system