Thanks for the query,Vitiligo
is an auto immune disorder.
Its course cannot be predicted,
In many patients it just remains as a single patch.
Please dont get tensed as stress
increases the chance of further spread.
You can meet a dermatologist
and start treatment for the existing patch.
Let me know if you have any other doubt.
you can ask a direct question to me on this forum, following the below link.
Wishing you a good health.