Collection of Pus

Skin | Dermatology | Collection of Pus (Symptom)


A collection of pus is a pale yellow or green, creamy fluid found at the site of a bacterial infection. When a pus has a reddish color, it has been mixed with blood, but this is a superficial coloring, and does not involve the actual process of fighting off infection.

Pus is composed of millions of dead white blood cells, partly digested tissue, dead and living bacteria, and other substances. A collection of pus within solid tissue is called an abscess, whereas a visible collection of pus within or beneath the epidermis is known as a pustule or a pimple. Pus consists of a thin, protein-rich fluid, known as liquor puris, and dead leukocytes from the body's immune response (mostly neutrophils - white blood cells).


Brownish pus will sometimes form when the liver is abscessing, usually due to an amoebic attack. Green pus may also form, which simply reflects a high level of myeloperoxidase in the neutrophils. This is an antibacterial protein naturally secreted by neutrophils, which has a vivid green color. In rare cases, pus may be blue, usually when the neutrophils have been active in fighting off the bacterium Pseudomonas aeruginosa.

Diagnosis and Treatment

Topical solutions can be used to help assist in fighting off a bacterial infection, and if pus continues to form in the same location over long periods of time, it is probably a sign of a chronic infection that should be analyzed by a physician.