If your skin is not simply dry, this could be scabies. Although it is a sexually-transmitted infestation of mites, you could get it from any close and prolonged contact with someone who has this.

also toes and under arms

i m going to email you a website that tells you all about scabbies. you can get it from skin to skin contact which includes sexual contact and even holding hands. you can get it thought furnishings, bedding, they can survive a few days on these things per the website.