My 11 months old baby developed some kind of rash looks like little mosquito bites all over body and it is red?

He has red rash all over the body looks like mosquito bites and it is red. Also his cheeks are red and seems kind of itchy does anyone know what it can be?

Thanks
It looks like red patches and it has tiny bumps like mosquito bites and it happened after bath and spreaded all over the body.

Maybe chicken pox’s

urticaria… which is itchy and red and looks like mosquito bite which can be merging and spreading…

eczema