Praise be to Allaah.
Bleaching the skin is done for one of two reasons:
it is done in the pursuit of beauty and perfection. This is not
permitted because it involves changing the creation of Allaah, and because it is regarded
as being in the same class as tattooing, practitioners of which were cursed by the
Messenger of Allaah
(peace and blessings of Allaah be upon him).
It is done to remove a fault of blemish, such as a black spot or
something similar on the hand or elsewhere, which a person bleaches in an attempt to
remove the blemish. There is nothing wrong with this, because it is counted as removing
faults. And Allaah knows best.