What is a boil?

Boils, also called furuncles, are an acute, deep-seated, red, hot, tender nodule or abscess that is forms in an area with staphylococcal folliculitis.  Staphylococcal folliculitis is inflammation and infection of the hair follicle that is caused by Staphylococcal bacteria. Boils, folliculitis 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 boils?

Boils 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 and progression to form a nodule or abscess.  

How are boils 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.