I noticed this phenomenon recently. I have severe eczema requiring steroids once or twice a year. It is over most of my body. I have a shower that has a good deal of water pressure and I ease my way in one small area at a time. I have never tried crack but I can only imagine it is a similar feeling. The worsening that some describe is, I suspect, a result of scalding as the hotter the water, the better the feeling and the pain sensation is very much lessened. I find that if I am careful in terms of heat and time exposure I can limit some of the worsening described. Incidentally, I have never subscribed to the idea that dry skin is the issue in my eczema. Yes it is flaky, but I experience it more as severe itching, reddening, and then flaky skin, like the skin is sloughing off. My eczema clears rapidly in response to medications like corticosteroids that eliminate the allergic response and doesn't respond at all to efforts to eliminate dryness.