Brown hyperpigmentation and White depigmentation

I'm a 48 year old female and have developed flat brown splotchy hyperpigmentation on my face and arms.  What is this?  Is it hormonal?  How do I get rid of it and prevent more?  I also have areas of depigmentation (small white spots) all over my arms and legs.  Again, what is it and can I get rid of it and prevent more?  I'd appreciate any information about causes and potential treatment options.
Thank you.

[Setaka]

There are two causes for what you describe...

One is a lack of melanoma in certain areas called Vitiligo.  It can be more prounounced in people with autoimmune disorders or thyroid disorders.

Another reason - affects construction workers or people who work outside in hot climates - is tinea versicolor (or pityriasis versicolor) where people sweat on their skin and develop a fungal infection.  Sunlight does not pass through the fungus so intermittent parts of their skin are tanned while others are lighter colored.

There is no known treatment for Vitiligo.  Usually it's the psychological aspect of the condition that causes the most problem.

For tinea versicolor, treatment with an antifungal agent rids the patient of the fungus, but the person must wait till the tan fades to get an all over tan to cover the area of loss.

[Lessu7]

Thank you for the info.  My dermatologist said it was not Vitiligo so it's probably the tinea versicolor.  I'll try to find out about getting an antifungal agent.  What about the brown splotchy areas?  Any ideas?  Thank you.