hi i had gone through your query and understand your concerns. i would come up with the possibility of 
ALLERGY -
URTICARIA is the cause for your sufferings.
-The body’s defense mechanism, the immune system, reacts to the allergen as if it were a dangerous organism, in trying to neutralize the antigen, the body releases 
histamine, which produces the allergy symptoms. 
Possible causes include;
-genetic predisposition
-emotional stress
-internal diseases
-physical factors like heat,
cold,sun,exertion,pressure,vibrations.
-food and food additives
-Drugs
-insect bites
-intestinal worms
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