Furuncles, or more commonly known as boils, are bacterial infections in the skin caused by a bacteria called Staphylococcus aureus. Very similar to pimples and cysts, boils are formed when a hair follicle and its surrounding tissue get infected and inflamed by the bacteria. This occurs in the first stages of a boil.
This immune reaction will cause the puss to fill up the infected tissue surrounding the hair follicle. The inflammation of the surrounding tissue, coupled with the accumulating puss will cause a large, smooth, reddish, and painful bump filled with pus.
It is referred to as a carbuncle when multiple hair follicles in close proximity all get infected and form multiple boils. Although similar, boils are still different from pimples the latter only affect the sebaceous gland and its immediate surrounding area. The boil, on the other hand, goes as deep as the hair follicle, affecting a larger area. Therefore, boils cause a larger, more painful, puss-filled bump.
Stages of a Boil
There are several stages of a boil: the initial infection, the inflammation, the swelling, and the drainage and healing. Here are those stages.