What Are The Hives All Over The Body And Raised Purple Spots On The Tongue?

my daughter is 3 yrs old she weighs about 28lbs and is about 36". I did pick her up from school a week ago tomorrow with head to toe hives (so i think) and they are not completely gone but look and feel more like goosebumps. And tonight i was brushing her teeth and noticed her tounge looking very reddish purple and it had dark raised spots, what could this be????