Wednesday, September 29, 2010
It is almost always caused by infection by the bacterium Staphylococcus aureus, resulting in painful swollen area on the skin caused by an accumulation of pus and dead tissue.
Individual boils clustered together are called carbuncles.
Boils are bumpy red, pus-filled lumps around a hair follicle that are tender, warm, and very painful. They range from pea-sized to golf ball-sized. A yellow or white point at the center of the lump can be seen when the boil is ready to drain or discharge pus. In a severe infection, an individual may experience fever, swollen lymph nodes, and fatigue. A recurring boil is called chronic furunculosis.
Usually, the cause is bacteria such as staphylococci that are present on the skin. Bacterial colonization begins in the hair follicles and can cause local cellulitis and inflammation.
Additionally, myiasis caused by the Tumbu fly in Africa usually presents with cutaneous furuncles. Risk factors for furunculosis include bacterial carriage in the nostrils, diabetes mellitus, obesity, lymphoproliferative neoplasms, malnutrition, and use of immunosuppressive drugs.
The most common complications of boils are scarring and infection or abscess of the skin, spinal cord, brain, kidneys, or other organs. Infections may also spread to the bloodstream (sepsis) and become life-threatening.
All furuncles must drain in order to heal. Draining can be encouraged by application of a cloth soaked in warm salt water. Washing and covering the furuncle with antibiotic cream or antiseptic tea tree oil and a bandage also promotes healing. Furuncles should never be squeezed or lanced without the oversight of a medical practitioner because it may spread the infection.
Furuncles at risk of leading to serious complications should be incised and drained by a medical practitioner. These include furuncles that are unusually large, last longer than two weeks, or are located in the middle of the face or near the spine.