Applying coverup does not invalidate your wudu’, so you are allowed to pray with the wudu’ you have performed before applying the coverup for vitiligo as long as you did not break the wudu’. However, while renewing your wudu’ you are required to remove the coverup if it has a coating that prevents water from coming in contact with your skin.
Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states: As a woman, you are definitely allowed to pray with the wudu’ you performed before applying the coverup for vitiligo as long as you did not break the wudu’. Applying coverup does not invalidate your wudu’. However, while renewing your wudu’ you are required to remove the coverup if it has a coating that prevents water from coming in contact with your skin. If, however, it has no such coating and is merely a colouring without any visible layer, then you can make wudu’ by simply passing water over it.
If, on the other hand, this coverup is a kind of medication that is supposed to cure the skin condition you are suffering from and by removing it the healing process is impaired or adversely affected, then you need not remove the same; you can simply make wudu’ by washing all other parts, and then wiping over the affected spot with wet hands—if it can be done, otherwise you are allowed to simply skip that spot, and your wudu’ will be still be deemed as valid. It should be stressed, however, that the last-mentioned exception from washing the affected spot is valid only when the above condition and its treatment prevent you from using water.