or furuncle or furunculosis
Inflamed pus-filled swelling due to staphylococcus skin infection at a hair follicle.
It is painful and feels hard. Boils usually occur in hairy areas exposed to friction and maceration. Scratching an existing skin disorder may introduce staphylococci on the skin into hair follicles and cause a boil to arise. A carbuncle occurs when several adjoining boils merge. Healing requires discharging the pus. Treatment involves antibiotics.