Sudden, severe nappy rash in 2yr old DS

[IcouldstillbeJoseph]

he's never, ever suffered before (apart from one vile day when he'd eaten almost a whole watermelon...) anyway, his bottom is so raw and painful at the moment. He screams wildly when I try and clean him, he is obviously distressed by it.
I use cloth nappies FWIW, but, like I say, never had a problem before. I've been trying Sudocrem & Metanium but doesn't appear to be helping.
Any ideas why this is happening now and what I can do?
He's just got a new sister on the scene, I only mention it as I can't think of anything in his life that's changed...

Are you using wipes or cotton wool and water/lotion? If wipes then change to cotton wool and water or lotion till its gone. Metanium is the best for nappy rash. Has he eaten anything different? Could it be an allergy or intolerance?

Is he teething?

Can you switch to disposables for a couple of days until it clears up? Or change him every hour?

We started using disposables with DS1 when he was two, in part for this reason. Where he was cutting his back teeth, his wee was so strong that it made him really sore.

Could it be thrush? If it's appeared suddenly and isn't clearing up with barrier creams it might be worth a trip to the GP to get him looked at. Otherwise try plenty of nappy free time, and I find bepanthen to be good, with lanolin cream on really sore bits (not all over though otherwise it might affect the absorbency of your nappies). Good luck with it, dd1 suffered terribly with her bottom and needed steroid creams

Not eating anything differently. Have been using wipes but will try cotton wool instead.
I wonder whether he is teething as he's chewing a lot recently - but I can't see anything in his mouth. Although he still has all his molars to come (a v late teether) so it's a possibility. Do they tend to get more bothered by these big teeth as he's not batted an eyelid over any teeth erupting before?
I would try nappy free time but have 3 wk old and have enough on my plate without clearing up puddles of pee!
Thank you all

I'd take him to the GP - my dd had this in very similar circumstances. Almost looked like chicken pox - pus filled spots etc. turned out to be a virus.

Think happened to my daughter- was thrush & cleared up in days with canestan

Have you changed his milk at all. I changed my LO's and the same thing was happening. His bottom was red wore but I also had 10 days worth of only pooey nappies. Only stopped when I went back to his old milk. Hope it clears up soon.

Alg08 - he doesn't really have much milk anymore, so it can't be that.

Thanks to all - been cleaning him with cotton wool and water today and using Metanium. Seems a little better but not much. His poo smells different too, sorry for TMI - bit looser and bit sticky. Was thinking defin teeth but had a good feel of his gums earlier and nothing palpable. Will see GP Mon if not better I guess