What is a carbuncle?

A carbuncle is an area composed of several, multiple coalescing boils (see boils).  A boil, also called a furuncle, is an acute, deep-seated, red, hot, tender nodule or abscess that forms near hair follicles infected with Staphylococcus bacteria (folliculitis). Folliculitis, boils and carbuncles represent a continuum of severity of Staphylococcal infections.  Carbuncles are the result of the infection of several contiguous hair follicles, as opposed to one in furuncles. These lesions are diagnosed by a bacterial gram-stain and culture.  

What causes a carbuncle?

Carbuncles are caused when Staphylococcal bacteria penetrate the hair follicle and break the integrity of the skin.  This leads to local inflammation of the hair follicle that progress to formation of a nodule or abscess.  

How is a carbuncle treated?

Incision and drainage are often adequate for treatment of abscesses, boils or carbuncles.  In severe cases systemic antibiotic therapy may help speed resolution of the infection.


Wolff K, Johnson, RA.  Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology. Sixth Edition. 2009.