Infection of a hair follicle.
A form of small skin abscess involving a sebaceous gland: furunculosis.
Boil: small, painful lump in the skin that has a core of dead tissue and surrounding inflammation. Caused by bacterial (staphylococcal) infection through a sweat gland or hair follicle, it produces pain, redness, and swelling. Treatment is by antibiotics, applications of moist heat, and surgical incision and drainage if necessary.