Moles Halo Nevi | Dermatology Education Moles Halo Nevi Video
May 29, 2017

Dermnet Videos

Moles Halo Nevi

Halo nevi occur primarily during adolescence. The average age of onset is 15 years. The incidence in the population is estimated to be 1%. Most halo nevi are located on the trunk; they never occur on palms and soles. They may occur as an isolated phenomenon or several nevi may spontaneously develop halos. A pre-existing nevus develops a surrounding rim of hypopigmentation that heralds the gradual disappearance of the nevus over several months. The depigmented halo is symmetric and round or oval with a sharply demarcated border. Skin biopsy shows a junction or compound nevus surrounded by a dense infiltrate of lymphocytes. There are no melanocytes in the halo area. Halo nevi appear to be a host response directed against the nevus cells. Focal atypical nevus cells may be seen though the majority of the pre-existing nevi are benign. The halo usually re-pigments over a few years. Woods light accentuates the halo. Halo nevi also occur in people with vitiligo. A halo may rarely develop around malignant melanoma, but in such instances it is usually not symmetric. People with halo nevi should have a full skin examination to look for vitiligo and also to screen for melanoma. Removal of a halo nevus is unnecessary unless the nevus itself has atypical features. Parental concern over this impressive change is often reason for a conservative excision. In such cases, the mole part of a halo nevus may be removed by shave or excision.