Boil

Boil, collection of pus accompanied by inflammation in the skin and its underlying tissues. Boils are also called furuncles and often look like large pimples. Roughly circular in shape, boils usually block the small cavities, or follicles, from which hair grows. They occur most frequently on the scalp, in the armpit, and in the groin. People who have lowered resistance to disease-causing agents, diabetes, or very oily skin are especially prone to boils.

Boils are usually caused by a type of bacteria known as staphylococcus, which enter the skin through pores or small wounds. The first sign of the infection is a sensitive lump under the skin. The swelling spreads and the area becomes red, painful, and warm to the touch. Gradually its center, or core, softens and liquefies as pus forms. Within a few days the pus forces itself to the surface, forming a yellowish tip, or head. When the tip ruptures, pus is released, and the pain caused by the swelling and pressure is relieved. The infection may continue to drain for several days, and complete healing may take from several days to several weeks depending on the size of the boil.

Treatment of boils includes the use of hot compresses to bring the infection to a yellowish tip or to cause the reabsorption of infected material into the bloodstream. Antibiotics may be prescribed by a physician to control the further growth of the bacteria.