Urticaria (Hives) Types, Symptoms and Causes

What factors cause hives? The core problem is a trigger. Once it leads to the excessive amounts of histamine or other chemical messengers, the body surface suffer. As a result, the patient’s blood vessels simply open up. That is how the reddish or pinkish spots appear, forming the tumor and rash at one time. The attacked zone becomes leaky. Here is why histamine may exceed its normal level: an allergy; infectious bacteria or virus and a particular group of drugs.