I get small pus-filled pimples that flare up on the front/insides of my thighs, sometimes on my knees and backside, and also occasionally on the backs of my hands and my face. They are notably deep down in the skin, they can be felt as a lump before they are ever seen. Once they appear in one place, they tend to come back on the exact same site, to the millimetre - I know this because when they go they often leave a bruise that lasts (so far, literally) forever. Happily this doesn't happen on my face or hands.
In my case they are inevitably a sign that my gut is not managing to digest something - often dairy products, there is one specific cheese that will always trigger it in less than a day !
My treatment is to burst the pimple (only satisfying part of the process !
), and then wash with as mild and chemical free a soap as I can find. (The more chemicals there are, the more the spot will continue as an inflamed, angry red scabby spot.)
My theory, for what it is worth, is that this is the result of leaky gut syndrome; it is the skin acting as an organ of excretion to get rid of imperfectly digested molecules that have prompted an immune sytem response, the pus being that "foreign" matter. If you don't wash the area after the pus is cleared out (and it should just be reabsorbed naturally eventually, even if the boils/spots are not burst) then skin bacteria like staphylococcus aureus may get into the
open wound and cause further inflammation; equally, because of the abnormal inflammatory response that accompanies Crohns Disease, harsh chemicals in soaps may prolong inflammation.
Like I said, it's a theory. No facts to back it up really, just reasoning; I often wonder if it is the MAP/CRohn's bug just deciding to be thrawn and gnaw away at something. Whatever it is, in my case at least it always goes away, after a couple of weeks or so at most, without any drastic professional medical intervention such as antibiotics.
As the others said, it's something you want your doc to keep an eye on, but it sounds like you have got a safe enough treatment with the wash at present.