Boil

A boil is an infection of a hair follicle and the tissue surrounding it, which forms a red, painful, pus-filled lump. It frequently appears in areas of friction or sweat, such as the neck, armpits, buttocks, or thighs.

Common symptoms:

• A reddened, warm lump that grows little by little.
• Pain when pressed and, later, a white or yellowish head.
• Sometimes fever or several boils clustered together.

Common causes: It is usually due to bacteria that normally live on the skin and enter through small injuries; diabetes or a weakened immune system can make it more likely.

Which specialist treats it? The general practitioner resolves most cases; the dermatologist provides guidance when they are recurrent, and the infectious disease specialist gets involved if the infection becomes complicated. If the boil grows, hurts a lot, or is accompanied by fever, it's a good idea to have it checked rather than handling it at home.