Melasma is a common skin condition caused by brown to gray-brown patches/discoloration on the face.  It mostly presents itself on the cheeks, chin, nose, and forehead.  

It is more common in women than men, and pregnancy is a common cause of Melasma.  

It can affect women taking birth control, and can be due to hormonal changes

You can use hydroquinone for Melasma:    ClearChoice Enlighten