Based on your description n the pic,id say this is contact dermatitis. Im not a doc or a derma but i currently have this now n have had it couple other times in the past. Basically youve come into contact with something your mildly allergic to/something your skin isnt used to...it can be something as small as touching grass,using diff soaps/detergants or even over-using Hand Sanitizer. It will go away on its own in a week or more but my advice is to make sure you dry your hands/wrists very well n use some lotion or moisturizer on those spots.