Hives, loss of appetite, dehydration?

My daughter is 18 months, i took her to the doctor yesterday because she woke up with hives on her belly. He said he doesnt know what its from and told me to give her liquid claritin, which isnt working very well. She woke up this morning and she is covered from head to toe with hives. He told me to call back in a couple of days if they didnt go away, but they are so bad i think maybe i should call him today. (but it hasnt even been 24 hours yet since he seen her) What would you do? And has anybody ever heard of loss of appetite, and maybe even dehydration with hives? She has barely eaten anything, and when she woke up this morning her diaper was barely wet, and normally its soaked, but shes been drinking fine.Hives, loss of appetite, dehydration?
The symptoms present as an allergic reaction to something,do not wait to see the doctor.Go to your local emergency room.Review in your mind anything that you may have changed in your regular routine such as soaps,household cleaners,bedding,animals,recen... work inside the home,such as painting,laying carpet.Take any meds to the E.D.with you.Please do not wait for the doctor,some reactions can cause respiratory distress in children(which they cannot handle for very long).
you can go to A and E dep and have your baby be checked right away...is she well by herself? she fretful?in distress? feeling itchy? if your gut feeling is that something is not right with your baby, go with your instincts...

i got a 9month old baby, and im always warry of things....
STOP READING THIS AND GET YOU CHILD TO THE ER