Dry skin, flaky skin, fissures etc are very often caused by a lack of essential fatty acids.

This is a quite complex biological/chemical subject but in short: the body needs a few fats [fatty acids] from food intake and can’t produce them from other fats [these are called essential fatty acids][EFA]

Much healthy fatty food may contain these EFA, but the easiest way to get them is by using some olive oil and sesame oil and some fish.[nuts etc]

Oils like sunflower oil and soy oil etc are absolutely NOT advised, but you will find this often mentioned on otherwise “authoritative” websites.