A thick patch of white scales is characteristic of psoriasis. Psoriasis is a chronic autoimmune condition that results in the overproduction of skin cells. The dead cells build up into silvery-white scales. The skin becomes inflamed and red, causing serious itching. Eczema, or atopic dermatitis, may also be a long-term condition affecting the skin. It occurs because of a hypersensitivity reaction. This causes the skin to overreact to certain triggers, such as dyes, fabrics, soaps, animals, and other irritants Also look at this website it discusses different skin problems specific to diabetes https://www.aad.org/public/diseases/other-conditions/diabetes-warning-signs
Sorry you have itchy legs. I know when I get dry skin, I become very itchy. I've got a product I like that is a heavy balm that I heard about on a radio program. It's gotten at places like CVS or Walgreens. Aveeno eczema Therapy itch relief balm. It was 16 dollars and lasts me a whole year. It does help with itchiness. I've never been diagnosed with eczema but do have dry skin. Eczema and psoriasis can both itch. Hyperpigmentation can occur from our scratching. Were you told you might be prediabetic after a physical when they checked your lab work? Type 2 diabetes is preventable and you can do diet changes and exercise, weight control often to control it so it does not turn into the real deal. So, I'd work on that! There is something called Lichen Simplex Chronicus. This happens when the constant scratching changes the skin. Seeing a dermatologist for guidance would be the best idea.