carbuncle, in medicine, a type of inflammatory staphylococcal infection of the skin. A carbuncle typically consists of two or more interconnected boils called furuncles; these are painful red nodules that form yellowish heads which burst to release pus and dead tissue. Carbuncles, however, are larger than furuncles, generally involve deeper layers of the skin, and have multiple openings for the drainage of pus. They occur most often in hairy skin areas or areas that are subject to friction—e.g., the back of the neck, the armpits, and the buttocks.
While simple boils can be eliminated by the application of hot, moist dressings followed by washing with soap, carbuncles may have to be lanced and drained, a procedure that is often followed by antibiotic treatment. After the treatment, poor hygiene may lead to a recurrence.