Answers:
The birth control can cause that as capably as perfume or fruit juice. I don't know why though. They certainly have an article just about skin problems in the Cosmo Style and Beauty magazine for Summer/Fall. It even say if you drink fruity drinks outside like margaritas you can return with spots on your upper lip because of the fruit juices soaking into your skin. Sounds grotesque but apparently is true.

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I doubt that both of those cause those, unless if you enjoy a negative effect to them. Do you stay out contained by the sun too much? That's the major effect of brown spots. Also, if you stay in a especially polluted area for a terrifically long time, that could also cause brown spots. I recommend staying shaded and washing your frontage after being within a very polluted nouns for a while.

Hope I helped!

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