What Causes Itchy Hives On The Body?

Have you ever heard of plankaseca it causes hives?Itching all over have talked to internist and she is trying to rule out allergic to meds have had a lot of health issues and with that have a port that keeps getting blocked that they have to unblock with meds. Had many blood transfusions. Had bariatric by pass surgery reversed. Have these hives that itch all over and can t get any relief.