An abscess occurs when an infection causes a pocket of pus to develop. Abscesses can develop on the skin, in the mouth, or inside the body. Bacterial infections typically cause abscesses. Pus develops ...
Medically reviewed by Marisa Garshick, MD A boil on your butt may be fluid-filled, itchy, or painful.An infected or inflamed hair follicle, called folliculitis, is the main cause of boils.Treatment ...