Thank you for your query on Healthcare Magic,
Your child had generalized urticaria
For itching you can apply a calamine
containing lotion externally over skin.
If there is severe itching
you can give atarax in prescribed dose for 2 to 3 days.
But the cause of allergy to be looked in to.
Any change in food, any allergy to pet animal or clothing should be checked.
If it is persisting consult your Pediatrician
for further advise.
Hope I have answered your query.