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 ...

A pilonidal sinus is a small tunnel that develops at the top of the crease in the buttocks. Trapped hair around the buttocks crease can lead to an abscess, and a pilonidal sinus may develop as a ...