Dermatologist vs trichologist vs specialist - understanding who to believe about whether hair loss is TE or AGA?

Typically, a Dermatologist with a scalp biopsy is what I would trust. After all, skin is an organ all to itself & a dermatologist is a specialist in skin (of which hair is an appendage of skin.) There is the possibility of a patient having both at the same time, however, with my patience, I explain that TE (telogen effluvium) will typically resolve over time, but AGA (androgenic alopecia) usually worsens with time, as it is a progressive disease. The dermatologist will assist the patient on treatment of both.