Are there instances where surface pus should not be removed?

Question

It is widely known that pus from an abscess should be drained.

For an open wound, however, I'm unsure if removing the pus is always the right option.

I can imagine three reasons why the pus should be kept:

1. Removing the pus could cause damage to the soft tissues surrounding it
2. Pus can be a barrier, blocking bacteria from reaching the skin, and trapping moisture in
3. Pus can "pack a wound", keeping it open while the tissues heal from the inside out

However, keeping the pus might cause further damage:

1. Bacteria produce toxins that can inhibit healing. These toxins can be present in pus.
2. The pus hides the wound, making it harder to monitor it.
3. The pus can act as a plug, preventing free flowing of wound drainage

Is it always a good idea to remove the pus from a wound? Or should it sometimes be left alone?

Answer 1

I agree with the comment from @CareyGregory.

1. Maybe, but wound treatment often includes debridement to remove the dead/dying/damaged tissue anyway. This also physically lowers the number of bacteria at the site of infection

2. Pus certainly isn't a barrier to bacteria, if anything it'll provide a nice moist, nutrient-rich environment for the bacteria to multiply in. In addition, some pathogenic species of bacteria are motile, so they can effectively swim though the pus to spread.

3. Pus generally isn't solid, so it can't hold the wound open as packing would. It is a liquid, which will conform to the shape of the container (wound).

4. Yes, toxins are present in pus from both dying (apoptotic, necrotic, pyroptotic) cells, immune response producing oxidative burst, cytokine release, as well as bacterially produced toxins such as haemolysins or cytolysins. Removing these is better than leaving as it prevents further damage to the wound and reduces the likelihood of disseminated infection.

5. Yes, pus could hide the wound and further infectious processes that are happening.

6. Maybe, I don't really know about this, pus generally isn't solid, but can accumulate behind a solid core, such as in the case of pimples/comedones that can progress to full-blown infections.