What Causes Brown Patch Of Dry Skin On Nose?

I have a brown patch of dry skin on the one side of my nose just below the inner corner of my eye. It feels slightly raised at the bottom end and looks like a big freckle. I am 64 now but was on the contraceptive pill for many years, during which time I did sometimes have dark patches of skin but these were flat, whereas this is rough and slightly raised.