ichthyosis vulgaris

I am 51 and have had ichthyosis all my life however, it was not diagnosed until 10 years ago.  Since then I have been on a cream Ammonium Lactate 12% which has helped considerably!  In the past 3 years though I have noticed a perplexing and growing problem.  When I get into water for 10 minutes or more my hands and arms turn white.  It's almost like they are covered in dead skin.  this does not hurt, itch or burn.  It is not blisters but is very unsightly and embarrassing!  The dermotologist is baffled.  She took biopsys and is very intriged however she does not think it has anything to do with the ichthyosis.  I still think there is a link and am wondering if anyone out there has had simular symptoms.