What Causes Drying And Itching Of Skin With Hot Palms?

Many years and different jobs--have recurring hot palms/skin dies and I usually pick off==just keeps doing it over and over-also similar symptoms on bottom of feet. (also is itching once I start picking and rubbing) Been to dermatoligist-tried several different gels/creams he gave up. Now am going to the allergist-finding allergies to many environmental things plus foods.... am currently taking shots. any idea??? This is not a contact form of anything-skin get real dry and dead and sometimes very hot.Trying to think back when started, can't recall---could any surgeries have caused some internal problem?