<<Disclaimer:  Verify this information before applying it to your situation.>>

There may be an increased risk of hives in celiacs due to the leaky gut
which allows macromolecules into the blood system where they dont
belong.  This makes the developement of allergic reactions to the
allergens more likely.
On the good side The permeability can iimprove with strict adherence to a
GFD. Avoidance of the allergen if known is helpful if known
Prescription mediacation may help to reduce the severity of the illness.
The other consideration is whether this could an atypical form of
dermatitis herpetiformis.
Joe Murray
Disclaimer( not mediacl advice)