Boil: Inflammation of the superficial skin follicles

The boil is caused by an ‘inflammation of the superficial skin follicles.  Shows a central necrotic tissue surrounded by a nodular infiltrate hard and painful.
The causes:
In the skin pores are numerous, in turn connected to the glands that produce sebum, a fatty and oily.  The fat in this it exercises a protective action against the skin covering with a layer which also has the function of feeding, moisturize, lubricate and make the skin more elastic.
It may happen that the excess fat is to block the pores, interacting with the bacteria on the skin.  It thus generates an inflammatory response resulting in the formation of pustules or boil.
It should be noted that the obstruction does not always evolve in the pores boil.  For example, if the mixture of grease and germs into contact with the air forming the points blacks on account of a chemical reaction of pigmentation. Acne hornet’s nest and are generalized events that include a number more or less universal than boils with intense inflammatory component.