Hi welcome to Health care magic forum. Your problem is called utricaria happens due to exposure to some external or internal allergen . Allergen is a substance to which you are allergic . internal allergens may be foods or drinks you take day before the occurance. If they are continuous it is in the regular food but started recently.
External allergens are the things you use externally like sprays, powder, deodorant, new clothes, bed sheets, towels, under garments which you have purchased recently and are of new brand.
Besides i advise you some diet recommendations as avoid taking brinjal, egg, fish and sea foods.
Take more of green leafy vegetables, pulses, sprouts, meat, milk,fruits, juices, and dry fruits to improve blood, general health, resistance, and stamina necessory to withstand such things. Wishing for a quick recovery and thanks for calling.