Blotches, rashes, hives, no idea?

[Snozberry]

For the past few weeks my toddler has been coming out in small red blotches on her face and sometimes back/neck. They aren't spotty, it's under her skin, goes away within 30mins max. Sometimes there is a raised white bump, in an irregular shape as if she has scratched herself but she hasn't, which goes away just as fast.

Two doctors had no suggestions, I asked if maybe an allergy and they were a bit "meh, maybe" and suggested going away and trying to figure out what to. But ultimately as it goes away on it's own no concern?

I basically have no idea where to start or if it is even an allergy and wondered if anyone here had any advice or suggestions please.

She is generally a pale and rosey cheeked kid so this is driving me nuts analysing every blotch.

My DD1 gets this all the time and it's allergy related for her. She gets it when she is about to get some sort of virus as well. She still gets them and she's almost 5. She used to get a large cluster of them that would drive her mad with the itch so a dose of piriton did the trick. And the GP also prescribed a mild antihistamine cream for her for when it got bad.

Yes, my DD(5) gets this after a virus - post viral uticaria. It comes and goes over a couple of weeks then disappears. I give piriton to help with the itching.

That's interesting because she was at the tail end of a 2 week cold virus when it started happening. Thank you both.