What is a furuncle vs. a carbuncle?

A furuncle, also called a boil, is an infected hair follicle, whereas a carbuncle is several infected hair follicles, or boils, under the skin that converge to create one pus-filled sack above the skin, according to WebMD. Deep carbuncles are more prone to scarring than furuncles or superficial carbuncles.

Furuncles and carbuncles are more common in hairy areas of the body. These infections are usually caused by Staph bacteria, which may be methicillin-resistant, also known as MRSA. The bacteria in furuncles and carbuncles is contagious and able to spread to other parts of the body or from person to person, according to WebMD.