most likely, it's 黄褐斑, not 老年斑.

you could also compare yours with the pictures(search for pictures yourself) on baidu.

nothing really works, it may go away by itself or you can try somethings here:

http://www.baidu.com/#wd=%E9%BB%84%E8%A4%90%E6%96%91&rsv_bp=0&tn=baidu&rsv_spt=3&ie=utf-8&rsv_sug3=13&rsv_sug4=2226&rsv_sug1=11&oq=huanheban&rsv_sug2=1&f=3&rsp=0&inputT=2626