Talk to Dermatologist on Scalp & Dryness

I have been experiencing persistent dandruff and severe itching for the past 8 months. The dandruff affects my entire scalp and also appears on other body areas, including inside and around my ears. The flakes are white and form a thick layer on the scalp. No medications, shampoos, or treatments have been used so far. Hair fall has also started, and the itching is constant on the affected areas. Please advise on the possible cause and recommended treatment. If you need more details, please let me know.