Which type of specialists do I need to consult for scalp related problems?

For scalp related problems you should see a dermatologist. However depending on your issue there might be hormonal problems as well.

In my opinion, you should see a dermatologist who specializes in hair loss. They will do a good examination, often with magnification as well as history and possibly biopsy and blood work.PRP hair md.com

If you feel you have a Scalp Problem or Condition then you need to seek out a Dermatologist, they can review and assess your scalp, diagnose a condition and help you with a treatment plan perhaps. There are a few tests that may need to take place but this can be determined at a consultation.

There are hair transplant surgeons that specialize in the diagnosis and treatment (non-surgical and surgical) for hair loss. Also Dermatologists are often good choices

Seeing a dermatologist who specializes in hair loss would be ideal, in order to take a full history and examination that may require also a scalp biopsy.  Based on the diagnoses, a treatment plan can be recommended.
Good luck!