A boil is an inflamed, painful, pus-filled swelling under the skin. It is caused by a bacterial infection of a hair follicle. Clusters of boils may interconnect to form a carbuncle.
Common sites of boils are moist areas of skin, such as the groin, or areas where friction occurs, such as the neck.
Recurrent boils may occur in people with diabetes or those whose resistance to infection is lowered. Boils often clear up without treatment.
They may burst, release pus, and then heal, or may just gradually disappear.
A large, persistent, or very painful boil may need to be drained by a doctor. Antibiotics may also be prescribed