There is a long list of causes of hives like ingestion of food items, inhalation of chemicals, infections, worm infestation, autoantibody
Being gluten free
will work only if it is the cause. Most of the times we can not reach at the cause.
For the time being you start using oral antihistaminics like cetirizine/levocetirizine
regularly and visit a dermatologist
for further management.
Dr. Ajit Singh Kulhari
MD - Skin & VD