What is this rash?

[Rashboy]

This rash has come up on my four year old and I don’t know what it is? He has a runny nose and a bit of a cough but no temperature, in good form. The rash feels smooth and isn’t blistered or rough like sandpaper. It’s not in rings. I think it could be an allergy to new pjs but he hasn’t been wearing them all day and he wore them the night before and the rash only came up today. No new washing powder or foods etc. I think the rash has got worse from this morning. Does anyone know what it is?

It looks like a hive type rash, my dd has this most days and it looks very similar.

Have you tried antihistamines?

I gave him antihistamines but it hasn’t improved since.

I suffered with very similar rashes as a child mine was a food colouring allergy