My skin is extremely dry no matter how am applying...

What is the treatment for dry skin?
1. Keep skin as moist as possible
2. avoid prolonged or repeated showering
3. Rub your skin skin gently
4. Using natural masks and beauty masks 2-3 times a week
5. Drink plenty of fluids
6. avoid smoking and alcohol
7. Use sunscreen permanently and reduce skin exposure to heat
8. Make sure that you do not take medication that causes dry skin as a side effect
9. In the event of dry skin or other accompanying symptoms such as itching, see a  dermatologist, and usually autoimmune skin diseases that cause such as eczema, and dermatological conditions are treated either by topical cortisone, and antibiotics may be used Topical if there is inflammation
What are the causes of dry skin?
1. lifestyle
2. low skin care
3. Autoimmune skin diseases such as eczema
4. lack of fluid
5. Medication side effects
6. One of the symptoms of skin infections
What are the necessary tests:
1. Clinical examination by the specialist doctor
2. a sample from the effected area
3. Blood tests and immune antibody tests