Sunbed Treatment

Hi Guys, I have had one Psoriasis since age 21; now 38. My condition has worsened steadily between these ages and over the last few years have developed PSA. I finished my 2nd round of bath/sunbed treatment 3 weeks ago and ever since have had a madly annoying itch on shoulders and back of legs. Did not suffer like this after first round of treatment some 2 to 3 years ago. I have been traveling on holiday during these 3 weeks changing beds, washing powders etc so can't see a common outside factor as cause. Has anyone else had a similar experience please? Your comments/suggestions are appreciated. Cheers Gary.