Thank you for asking this question. It’s actually quite a common problem in darker skin types. All the areas where your skin experiences lots of movement, especially over joints like the fingers, the elbows and the knees will tend to pigment. There are quite a few product options for you.
We have had a lot of success treating pigmentation with a product called Lumixyl, which needs to be used on a continuous basis. There are other options such as Lamelle’s Brighter Concentrate or SkinMedica’s Lytera serum, but again any pigmentation home care product has to be used continuously so as to prevent the pigmentation from returning. I would suggest that a good place to start is to ensure you are applying a good SPF to your hands every day, this will also slow down the pigmentation process.