Post Puva Treatment itch

Hello. After having a third round of Puva treatment recently , I had to discontinue it due to an incredible itchiness, (Which is apparently one of the rare side effects of it) the like of which I've never experienced before , 3 weeks later and two different courses of very strong prescription antihistamines, I'm still incredibly itchy on my trunk ( no return of psoriasis however) I've also not got a an appointment with my dermatologist for three months, I wonder if anyone else here as experienced it and wondered how long it took for it to go away? Thanks in advance,