Boil

Boils
Furuncle
Specialty	Dermatology general surgery
Symptoms	Painful small rough skin growth
Causes	Bacteria ingrown hair

A boil, also called a furuncle, is a deep folliculitis, which is an infection of the hair follicle. It is most commonly caused by infection by the bacterium Staphylococcus aureus, resulting in a painful swollen area on the skin caused by an accumulation of pus and dead tissue.^[1] Boils are therefore basically pus-filled nodules.^[2] Individual boils clustered together are called carbuncles.^[3] Most human infections are caused by coagulase-positive S. aureus strains, notable for the bacteria's ability to produce coagulase, an enzyme that can clot blood. Almost any organ system can be infected by S. aureus.