From your description, it looks kike you are having vitiligo
which is characterized by development of white patches over the skin.
You owe the backache
to the medicines. Looks like you have been on long term oral steroids
Nowadays , we have many treatment options available for vitiligo. I would advise you to see a dermatologist
for proper assessment of the extent of the disease in your case and management.
I can assure you that we have so many options available for this disease nowadays and with proper management, you can regain the lost pigment.
Hope it helps
Best wishes for a speedy recovery
Dr Geetika Paul