Suspicious nodule on 4y/o sons scalp

[Littleolme]

Wondering if anyone has had something similar before and can advise. We noticed this nodule on my son’s head recently, it seemed to come out of nowhere and has definitely been getting bigger. It can be wet at times with a fluid that crusts over (more a small amount of watery fluid, not like pus), it can bleed a little, and he says it is sore. There is only this singular nodule, no other blemish’s etc anywhere else and he is otherwise fine within himself.
We have taken him to the GP twice this week and they gave us an antibacterial cream first and second visit gave us oral antibiotics saying it looks infected but not really identifying what it is in the first place.
From looking online the only things I can find that looks similar is the big C! I’ve attached some photos of it throughout this past week.

Oh my gosh that looks sore. I’d definitely be going back and insisting on tests.

Yes. I would go back and ask directly about that. Then at least they will be checking everything. Looks really sore.

I am not sure what this is but I would insist on am urgent referral to dermatology to get a definitive diagnosis. It is probably nothing and will disappear as mysteriously as it has appeared but it will put your mind at rest. Have the antibiotics helped at all? Is it itchy? Is your DC unwell in any other way?
Good luck and all the best. Virtual handhold.

yeah, the poor soul won’t let us touch it to clean it as it’s too sore. We just have to watch whilst he does it himself. He lets out a yelp when taking off clothes that touch it too, it’s a shame.
we will give the antibiotics another day or so and if it’s not notably better I will be insisting on an urgent dermatology referral. The only change I have noticed is that it looks less wet than previous days however I’m not sure if that’s because it’s getting more air as I managed to trim the hair around it to stop that matting in it.
Would rather be safe than sorry. Worried sick about it atm, praying it improves ASAP and hoping it is just an infection and not something more sinister.

its not itchy or anything, he doesn’t touch it or that as anytime something accidentally touches it he yelps in pain. Outside this, you would never know anything is wrong with him, he is totally fine within himself. Only time he complains of any pain is when something touches it. Otherwise you would never know.