hi welcome to HCM -hi i had gone through your query and understand your concerns. i would come up with possibility of ALLERGY is the underlying cause for development of your URTICARIA. -there are several causes beside for development of urticaria the possible causes include; -genetic predisposition -beside genetic predisposition,there is increased sense of heat,which increases considerably at the time of attack.this is more often seen in physical urticaria and allergies to food and drugs. treatment option; i advise you taking Homeopathic medicines gives safe and permanent cure for your complaints consult your local homeopathic physician for correct diagnosis of the case and remedy to fit your complaints I hope this is helpful for you, thank you