My 5 year old is allergic to penicillin so he was prescribed azithromycin. my concern is that he seemed to have some swelling in his throat not like the he did with the penicillin and so we have him some benadryl a couple hours later he is complaining that it feels like there is hair on his tongue. It looked like it had a ton of tiny red dots I gave him another dose of benadryl. It stopped his complaining buut now he is sitting there scratching his tongue. Should I make sure to give him another dose of benadryl in four hours ?I don t know how worried I should be