Are High Level Of The Stimulus And Hives Turning To Bruise Related?

My son is 2 1/2 and he is experiencing sporadic episodes in which he breaks out in hives that turn into bruises accompanied by sever swelling of his feet and ankles also his fingers and around his eyes. He was tested and has no allergies. And does not have the C1 disorder. He has a high level of the stimulus that controls the growth hormone. Are the two related?