What Is The Treatment For Pruritus Hiemalis?

I have a 26 yo M patient that presents with pruritis hermalis. We work in Iraq, so in the winter time it is very cold, and when the patient goes into a warm environment from the cold weather his pruritis flares up. It is extremely uncomfortable for him. I have given him atarax, hydroxydine, 25mg tid. This gave him some releif but his pruritis still persists. Can you please advise me on a course on action that will help this patient?