Thanks for writing your query.
After reading your query, it seems that your son is having viral fever
Viral fever is sometimes associated with rash
It will subside after the fever subsides.
You should get him examined by his Paediatrician.
You can continue giving him paracetamol(calpol
) for fever. Antihistamine can be given under medical supervision.
A Complete Blood Count(CBC) can be helpful.
Also maintain his hydration.
I hope this is helpful to you.