Thanks for your query
Seems like you have developed a patch of vitiligo
This presents with an asymptomatic white patch
over the skin.
Your disease is seemingly still in the early stage , so adequate treatment at this stage will help in preventing any further spread.
There are various treatment options available for the same ranging from topical drugs to oral drugs.
I would advise you to expose the affected area to sunlight everyday for atleast five to ten minutes.
This will help in regaining the lost pigment.
You should start treatment as soon as possible. I would advise you to visit a dermatologist
for proper assessment and treatment.
Hope it helps
Best wishes for a speedy recovery
Dr Geetika Paul