Suggest Treatment For Psoriasis And Eczema Sides Of Thumb

I have psoriasis and occasionally I get very hard patches of skin on the corners of my nails. At this time I feel like there are hard patches and split skin on the side of my thumb. It is sore and tender to the touch. I had ultravate medication in the house but it does not seem to be helping under the nail. Do I need clobetesol or halbatesol? I think when I went for a manicure the lady must of cut away skin on the side of my nails which shouldn't have been cut and its been sore for a while now. I forgot which cream the skin doctor gave me for this but I know it was one of the two or both at some time or another for my skin condition that usually is worse in the winter but my thumb really hurts around the sides of the nail. I am 57 years old with a history of psoriasis and eczema.