A skin infection caused by Staphylococcus aureus, beginning in adjacent hair follicles (see FOLLICLE). As the folliculitis becomes conﬂuent, a tender red lump develops which becomes necrotic (see NECROSIS) centrally with pus formation. A cluster of boils becoming conﬂuent is called a carbuncle. Release of the pus and an oral antibiotic lead to rapid healing.
Recurrent boils are usually due to a reservoir of staphylococcal bacteria (see STAPHYLOCOCCUS) in a nostril or elsewhere, so an intranasal antibiotic cream may be prescribed. Underlying DIABETES MELLITUS should always be excluded.