An abscess is the body’s way of trying to heal from an infection. Abscesses form after bacteria, fungi, or other germs enter the body. A skin abscess is a tender mass generally surrounded by a colored area from pink to deep red. It is a collection of pus that has built up within the tissue of the body. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pressed. The area of redness often extends beyond the swelling.