typically hives are not caused by teething. unfortunately there are hundreds of possible culprits. high on the list would be foods any medications soaps shampoos bubble bath products perfumed skin lotions laundry detergents and dryer softener sheets. finding the one (or more) causes is going to take some detective work on your end often by eliminating possible causes. there are no specific allergy test that will find it since there are so many possibilities. i do not know the age of your daughter so check with her medical provider first about using benadryl elixir - an antihistamine that help her until you find the cause.
my daughter gets hives recently that come and go trough the day. they started 3 days ago. could it be cause of teething. nothing new in her diet. will be on her arms at one time then go away and show up on another spot. have found them on her bottom back arms legs and scalp. all gone within about 2 hour. worst after waking up.