Cold urticaria

A child came in with history of full body rash and angioneurotic edema which would choke him within 5 minutes of exposure to cold water.
Patient has had this repeatedly and was hence scared even in rains to venture out.
Patient also developed increased thirst with gluttony.
Gave homeopathy bryonia with nat mur.
In 2 weeks behaviour changed, gluttony stopped, increased thirst stopped and cold urticaria stopped.

Note : Vasopressin is blocked by cold temperature. When vasopressin is low there is increased thirst with gluttony, cold urticaria is frequent.