Talk to Dermatologist on White Patches On Skin

I have weird white patches on my knee arm back chest and shoulders they are not so white like a tone or 2 tone lighter thn my original color it use to happen before 4-5 years too but not much and disappeared itself as well, but since one year it develops and disappears as well but few of them gets bigger and a bit brighter and doesn't disappear sometimes it itches as well and I've observed few of them first developed a rough scaly red patch tht use to itch and thn when it disappears leaves a white patch . Please answer my query soon m so tensed as I am newly married