Neurontin hives in treatment of Polycythemia Vera (PV) itch...

My great aunt has been diagnosed with Polycythemia Vera (PV) and is currently taking Hydrea (Hydroxyurea) to treat it. Her physician subsequently prescribed Neurontin to help with the chronic itching she experienced due to the PV and/or Hydrea. After taking Neurontin for about three months with much success where the itch had disappeared, she began to develop hives and stopped taking the Neurontin. Now she is experiencing this terrible chronic itching again, even worse than before she went on the Neurontin in the first place. Is there a further course of action or treatment? Should she plan on going back on the Neurontin? Has anyone experienced sudden onset of hives after taking Neurontin with some degree of success, and what was your course of action after that? Any help would be greatly appreciated. Thank you.