A 19-year-old healthy male complained of sudden onset of asymptomatic single patch alopecia on the occiput for three months. The round patch of non-scarring alopecia surrounded a pre-existent pigmented dome-shaped compound nevus, which did not change over time ( Figure 1 ). Trichoscopic features were compatible with alopecia areata (AA), and the patient decided on conservative management.
Figure 1 .
A 1-cm diameter round patch of non-scarring alopecia surrounding a pre-existent pigmented dome-shaped compound subtype nevus on the right side of the occiput.
Perinevoid alopecia (PA) is an extremely rare variant of AA associated with a central generally pigmented nevus [ 1 ] . Although the pathogenesis is still unclear, it is thought that PA is secondary to an inflammatory response against nevus cells or melanocytic structures [ 1 , 2 ] . Immune cells around the nevus attack the hair follicle, similarly to the destruction of melanocytes in a halo nevus, other nevocentric phenomena [ 2 ] . Surgical removal of the nevus may lead to hair regrowth a few weeks after excision [ 1 , 2 ] . Recognizing PA is essential to properly manage this unique variant of AA.