Could Itchy, Dark Pigmentation On Forehead And Corners Of Mouth Be Due To Intake Of Pork?

i am a 38 yr old female living in antigua in the west indies. i developed this dark pigmentation on my forehead and on the corners of my mouth some years ago.about 4 yrs ago. it can get really dark and itchy. the itching is worse at nights and the darkness can be 4 times the complexion of my skin. now it has spread to my cheeks and my whole face seem to be in danger of getting it. i have used dermafour cream and at first it seem to be going away but it came back worse. now a dr. told me that it is from eating too much pork. is that right.