i would definitely talk to the pediatrician or healthcare provider to find out whether or not they could use something like claritin. they have a liquid form and the doctor may say “hey you know what? you can try that instead”. it may not work as fast as the benadryl but it would be another option for them to try.
my son takes benadryl for his food allergies. it works but he ends up being so spacy. anything non-drowsy i could try?