Yeah, gross. I know.
But, working in a hospital, and with frequent direct patient interaction, I’ve noticed that pus primarily comes in three colors: White, yellow, and green.
So…does the color of the pus come from specific agent of infection, or is it due to whatever tissue is infected?
Or, is there some other factor that determines its color?
As a tangent, does the consistency mean anything? One time I had pus that was the color and consistency of hair gel. Freaky.
Ya know, I’ve cultured a lot of pus over the last twenty years and I can honestly say I’ve never considered the color issue before.
I do know that the more white blood cells there are in pus, the thicker the stuff is. I once saw some from an empyema (pus in the pleural cavity of the chest) that was so cellular it had turned into a solid, like firm, creamy-colored jello. The smell was remarkable.
As for pus of another color-I don’t know. There are some gram negative bacilli with certain greenish pigments (Psuedomonas) which might account for that particular shade.
I was under the impression that pus was like snot, and got greener the more dense it was. In fact, I was told that mucus gets greener when infected, due to the white blood cells. Is this false?
Details of the pus are always sketchy on account of the puke.
Since you’re looking for factual info, and not pus anecdotes, I’ll move this from MPSIMS to GQ.
This is the SDMB. This thread will devolve into pus anecdotes no matter where it is.
I read a study once specific to snot. It turned out (to everyone’s surprise) that the clear, thin mucous was equally likely to represent an infection as even the darkest, greenest, thickest snot.
Mothers and pediatricians the world over recoiled in shock, but the study was a good one. Not exactly on topic, but close.
I pay a little attention to the color and texture of purulent material, but rarely base treatment decisions on that aspect alone. Paying attention to clinical context and culture results is more helpful usually.
And lots of pus is streaked with red, mahogany, or even black material too. Hemoglobin, you know…
Ya know, this statement immediately makes me wonder… Inside or Outside your own body?
I wonder what the strangest color pus somebody has ever seen is. Green is already a bit up there… how about purple? Orange?
Well, outside of course. I have standards.
I’ve only ever noticed that it gets more of a cream color instead of flat white as it gets thicker. The stuff from the previously mentioned empyema was kind of opalescent. Almost pretty if you didn’t think about it too much. Also, I’ve seen material with a lot of white blood cells that were an inflammatory response I guess as the cultures never grew a thing.
It’s just a matter of time before someone posts links to pics.
I will not click.
I will not click.
I will not click.
Ya know, I love being an ER nurse, the melted chocolate that drains out of a Bartholin’s abcess makes your eyes water instead of your mouth.
I googled "Bartholin’s abcess " and will regret having done so for the rest of the day. :eek:
That should be white, gold and green, buddy. 
Gold from the cartenoid pigment staphyloxanthinproduced by staphylococcus aureus (the “golden” cluster), one of the commonest bacteria found in many purulent infections. White cells are…white, when there are a lot of them, and they produce myeloperoxidase, which is greenish. Chocolates and reds are common colors because of the presence of hemoglobin in various amounts from bleeding. As it breaks down, hemoglobin produces a variety of reds and greens…
I’m sure many other pigments are involved from both bacteria and white cells, but I think these are the major contributors to the colors you mention.
The surrounding tissue would not normally be a contributing cause of color. Smell can be a useful indicator of anaerobic infections. Infections communicating with fluid-producing parts of the body might be colored directly by those fluids (bilirubin, e.g.). And some bacteria other than staph have colors commonly associated with (but not pathognomonic for) them. Pseudomonas aeruginosa is often greenish or yellow, e.g.
“carotenoid”
Too early to catch my typos before the edit window closes.
Thanks, Chief Pedant. That’s exactly what I was looking for.
I’ve never seen purple (can’t think of any time I’ve seen a blue pigment produced, TBH), but I’ve seen some nice greens and oranges. Just the right bacterial types + low cellularity + hemoglobin = orange liquid, like a melted orange creamsicle, coming out from over a horse’s jugular vein (infected catheter site). Yaaay pus.
As a pharmacist (to be, 153 days!) , I’ve always heard that yellow is viral, green is bacterial. Now, this isn’t exact, and isn’t a diagnostic criteria, more of when to tell someone to see a doctor, and when to just recommend an OTC product.