Twiglett, I'm so sorryy. I understand why you are so discouraged and frightened because we have this in our family, too - my Mum.
I know under pressure, the last thing that helps is a barrage of helpful advice that turns out to be anything but...but my Mum's psoriasis cleared up almost miraculously when she drank the 100% oure Aloe Vera juice from Forever Living, and used the gel. When you are over the shock and confusion, if the probelm does develop further, there may be just the right alleviation once you have had time to take a deep breath and experiment.
But so sorry - it really is somehting to worry and get upset about.