I can understand you concern for the white spot on the vulvar region. It is quite common to find a spot of simple hypo-pigmentation after falling of superficial skin which is known as post inflammatory hypo-pigmentation. It is quite common to be conscious regarding a grave possibility of the same.
You do not worry about the same. apply a cream containing cortisone
and sun expose the area for 5 minutes. It will be alright in next couple of weeks.