Rash on 1yo arm

[Toothy321]

Hi, my 1yo (22 months) has had this rash on one forearm only for a few weeks. Pharmacist said it's heat rash but don't really see how / why it would only be on one arm. Any thoughts?

Doesn't seem to hurt/itch at all and she's otherwise well.

It looks dry, more like eczema

Thanks @DustyLee123 - could well be, I don't have it myself and haven't noticed it elsewhere on little one but will try some creams etc

I get a very similar looking patch on the inside of my wrist OP when I’ve been wearing my watch, for some reason post partum my watch strap now gives me eczema so I would agree with the other poster it looks dry and eczema like! Epaderm has been brilliant for my 2yo eczema