So about a month or so ago I scraped my knee. Resulted on a few significantly shallow scratches. I washed them with antiseptic soap and went about my day. I noticed that the wound was taking a long time to heal I'm talking weeks here. Infact it was widening it, would itch burn and become irritated. It wasn't until I noticed a few pimples growing out it which were full of pus that I went to see a doctor. Got antibiotics and a cream. The healing sped up and now all that's left is slightly dark skin. I noticed that a pimple would grow on the site, quickly fill with pass then either flatten like the pus got reabsorbed or burst and a day later boom another. What is going on???
I think it would be important to ascertain how you scraped your knee.
There is a possibility that a foreign body may have gotten into the wound, healed over and you will have recurrent infections until it is removed.
It might also be a hair follicle that was healed over like what is called a barber’s rash or pseudofolliculitis barbae.
Either way, you should go back to your physician and ask his orher opinion on these possibilities.
Please let us know what happened.
Something I forgot to mention in my original suggestions.
Go to any drugstore and purchase some surgical gloves.
Next time you notice pus in the area wear your gloves and put some on the tip of your index finger gently smearing it with your thumb.
Use a magnifying glass to examine your finger and thumb to see if you notice a foreign body or hair.
If so, your body may have healed itself but I would still check in with your physician to make sure.