Talk to Dermatologist on Pigmentation On Skin

Assalam o Alaikum Age:25 Weight:45 I have been suffering from a brownish spot (not itchy) since my teenage. Initially, it was over my upper back and arm and we assumed it was due to sun exposure. but now pigmentation is moving toward the collarbone and front body. Recently I visited a dermatologist and she told me that it was PV fungal and prescribed the attached medicines. I searched on the internet and found this condition as macular amyloidosis which is genetics because my mother also had the same pigmentation issue since her childhood. I want a second opinion should I start taking prescribed medicines or visit another doctor for a diagnosis? JazakAllah.