Artist's pet-white allergy

Almost all of my own work is black&gray. Recently I have reworked some of the older stuff in color. About half or the reworked aria contains Bright White and some Power White which were both used to cut greens, yellows and blue. I also used dark red, black, and an uncut blue (royal). Only the arias where I used any white were (still are) effected by a severe allergic reaction. The pure blue and red healed as quickly and cleanly as black. I have never experienced any problems ever using whites on anyone. The reaction is visible in the form of raised and blotchy arias of skin. It comes on as attacks and sometimes fades within an hour but occurs 3 or 4 times a day. It is accompanied be severe and maddening itching. A pre-deadener cream with lidocaine is the only thing that keeps me from scratching my skin off. When there is no flare-up my skin is healthy and fully intact (no scaling or oozing). Has anyone had experience with a negative reaction to white? I reworked forearm and lower leg with it over 6 weeks ago. The reaction may be a little less severe now, but it is diminishing very slowly. Any ideas on allergy longevity? Anything short of amputation that might irradicate the symptoms? Any statistics of the frequency of white reactions? Thanks for any insights.