It seems like a fungal infection
, otherwise called Tinea.
You should try using topical antifungal
ointment like Clotrimazole
. It is available over the counter. You should apply it twice daily, in the morning and in the night. The treatment should be for a minimum of 6 weeks.
They are known to recur. Therefore, application of the ointment should be continued for 2 weeks after the patch disappears.
There are many other causes for this too like Isolated Vitiligo.
It is ideal to meet a Dermatologist
and confirm the cause for it.
I hope this helps you.
Get well soon.