what causes swollen hands ans itchy palms?

When there's an allergic reaction that's localized to one area of the body, it's most likely due to some kind of local contact, e.g. your hands are reacting to something they're coming in contact with (e.g. do you use latex gloves? or a dish soap, hand soap or lotion that you could be allergic to?).  This is something that you should talk to your doctor about.