DDs both have a rash on torso any ideas what it could be?

[cliffdiver]

DDs (6 and 8) both developed a rash today.

It looks similar to chicken pox, but they both had it 5 years ago.

NHS and Dr Google don't seem to be throwing up anything obvious.

They both seem fine in themselves and no fever. Will attach pics.

Sorry, wrong image attached in post above

Could possibly be a post covid rash?

@Callimanco
That's really interesting. They've not had other symptoms but since I've posted this I've seen many other people posting similar unexplained rashes!