What is this rash?

[Trufflenose]

Yesterday I noticed an itchy bumpy rash on my inner arms. It feels like sandpaper, looks a bit like the rash DC had with scarlet fever. But it's only on my arms and a few blotches on each side of my waist and a tiny very mild patch on my chest.

I've had a mild sore throat and felt more tired than usual. I've also felt hot and sweaty on and off but am 44 and put that down to peri. No temperature.

I already take two lots of antihistamines for hayfever. No other medication. Eating nothing different. Been nowhere new. No change in washing powder etc.

It hasn't really changed in 24 hours. Anyone know what it could be? In particular whether it's contagious as I don't want to pass anything on.

Bumping this as its only improved a little bit after taking piriton on top of my hayfever medications. So itchy.

Is it worth bothering the GP about? Could it be a lupus rash?

Could it be scabies

Thanks for the suggestion. It doesn't look like it from the images on Google. Nothing in lines.

It also moves around a bit. Was originally only on inner arms and then moved onto back of the wrists.

Pharmacist thought it was an allergy but I've been taking so many antihistamines and it's still there, albeit slightly better. Also can't see how it can be an allergy as I've not done anything different from usual.