I would be pleased to answer your question .
You seem to be having an uritcarial allergic rash
You should take anti histamine like Hydroxyzine
. It is safe if taken in a small dose for a short period of time. You should however consult first with your pediatrician
to approve and prescribe you the same . The literatures say that is safest among the anti histamines
. However , AntiHistamines sensitivity is very high in infants .so be cautious and see the risk and benefit ratio .
I would in the mean time suggest you to apply over the counter lotion called SARNA lotion which you can apply 2 to 3 times a day .
Thanks and Take care