Raised, red spots on the skin can come from many sources. The spot may be a pimple, or it may be a boil or carbuncle. Determining the cause of the spot can be difficult, but you can use clues like the spot's location and size to help identify its origin.
Pimples are caused by a blockage in a hair follicle. The blockage is caused by an overproduction of oil by the oil glands in the skin as well as a buildup of dead skin. Boils, on the other hand, are caused by a bacterial infection in the follicle. The bacteria that causes boils and carbuncles is Staphylococcus aureus, or "staph." You can contract a staph infection from contact with an infected person or from contact with a contaminated item, such as a towel.
Pimples and boils may have similar appearances, particularly if the boil is just beginning to form. Both pimples and boils may appear red and raised. Over time, boils can become much larger than pimples, however. Boils can even join together and form a carbuncle, which is a cluster of boils that connect and form a single head. Boils and carbuncles are typically very hard and painful, whereas a pimple is not as hard and may or may not cause pain.
One way to differentiate between boils and pimples is their location. Pimples almost always appear on the face, chest or back, because these are the places where the oil glands become overactive and clog the follicles. Boils, on the other hand, usually form in the armpits, groin, buttocks or on the thighs. Both boils and pimples can appear around the nose or on the neck, however. Staphylococcus aureus can colonize the nose of an infected person and cause boils to appear and recur around the nose.
Pimples will disappear on their own without treatment, but you can use an over-the-counter medication or a prescription ointment or antibiotic to treat them. Boils or carbuncles often require medical treatment, however. The boil or carbuncle might need to be lanced by a physician if it is large. In addition, you will need to take an antibiotic to eliminate the Staphylococcus aureus bacteria and prevent the infection from spreading. If left untreated, Staphylococcus aureus can cause serious complications, such as septicemia, brain or spinal cord infection, heart infection or septic arthritis.