A boil is a circumscribed inflammatory process, caused by the entrance of pus producing germs into the skin either through the pores (the mouths of the sweat glands) or along the shafts of the hair, and in this way invading the glands which secrete a greasy material (sebaceous glands). In either case the pus germs set up an inflammation of the sweat or sebaceous glands, and the surrounding structures of the skin, and a small, red, itching pimple results. Rarely, after a few days, the redness and swelling disappear, and the pus, if any, dries and the whole process subsides. This is called a “blind boil.” But usually the boil increases in size for several days, until it may be as large as a pigeon’s egg. It assumes a bright red sharply defined, rounded shape, with a conical point, and is at first hard and then softens as pus or “matter” forms. There is severe pain of a throbbing, boring character, which is worse at night, and destroys the patient’s sleep and appetite. There may be some fever. The glands in the neighborhood may be enlarged and tender, owing to some of the pus germs’ escaping from the boil and lodging in the glands.
