Nappy rash?

S

If this is not okay please let me know! FTM, I just don’t know what to do, he’s had little blisters on his bum and now this rash appeared. I am currently on antibiotics that make him have an upset tummy. I’ve tried sudocrem, benpathan, let his bottom air dry and or dry it as well so it’s not wet. I use fragrance free wet wipes. Not sure if I shouldn’t take him to doctors as it doesn’t look nice or comfy 😩

I make sure that his nappy isn’t too tight too!