I thought I had calluses on my heel, I've try everything to get rid of it, but I noticed everytime I take a shower, bath, swimming pool my heels, big toe, and outer bottom of foot turns white, Ater it dries, it shows dark spots on these areas. I am not diabetic. Also nails are discolored, hard and brittle. Have been to dr. but they prescribed betamethasone dipropionate which did nothing. Could you give me a clue of what I might bedealing with.