The same pigment change can be seen in some women during pregnancy (when it is called chloasma), and as a side effect from the contraceptive pill. The pigment is light brown in a fair skin, and a darker grey brown in more olive skin type.
This condition can be difficult to treat. Depigmenting creams and lotions combined with diligent sun protection are routinely used but not always completely successful.
Depending on skin type, IPL light or NdYag laser may help some cases. A test area to judge the response to light treatment is usually undertaken at first.