she is allergic to something most likely. you and her allergist haven'tfound it quite yet and may never find it. some hives are caused by changes in temperature (like getting too warm). it is not necessary to know the cause of the hives in order to treat it successfully with antihistamines. i know hives can be frustrating but it can be very very difficult. even impossible to find the one (or many) causes.
my 2year old daughter keeps breaking out in hives every couple weeks to months. no food allergys or nothing in our home. she seen a allergist and its getting us no where i don't know what to do anymore. please help