It could be psoriasis, see doctor for diagnosis.
Bathing daily helps remove scales and calm sore skin. Add bath oil, colloidal oatmeal, Epsom salts or Dead Sea salts to the water and soak for at least 15 minutes. Avoid hot water and harsh soaps, which can worsen symptoms; use lukewarm water and mild soaps that have added oils and fats.
Apply aloe vera gel or cream thinly to irritated and itchy patches of skin and rub lightly.