Hi Viliam
There are many forms of Urticaria, and for this reason you should go and get it checked out by a Doctor and not rely on the diagnosis of your friends. I note that you say that you are a “pure vegetarian” unfortunately the foods that can cause this condition include peanut, tree nuts, soy and wheat. Other causes include bacterial infections, some drugs, insect bites, and a number of other infections. Treatment usually consists of finding the cause of this problem and then treating that. But you may also be given some medications to help relieve the symptoms until the cause is found.