A mole that has whitened around the perimeter is medically known as a halo nevus, a benign lesion involving multicellular pigment loss that usually requires no treatment. Halo nevi can be cosmetically disruptive and generally do not require treatment.
Halo nevi are common in adolescents and may be associated with immune system disorders, manifesting as whitening around the pigmented nevus, which tends to be oval hoochies and rounded white ring-like.
If the structure or color of the lesion is atypical, the pigmented nevus can be surgically excised and pathologically examined to exclude the possibility of malignancy. A part of the halo nevus will disappear on its own and the time may be 5 months to 8 years. Most of the white halos will not disappear and may be complicated with vitiligo, which needs to be treated actively if it appears.
It is recommended that patients who are willing to be treated should go to regular hospitals in time. Usually also need to pay attention to observe the affected area, if there is a change, need to seek medical attention as soon as possible.