The natural history of halo nevi: a retrospective case series.

The time period between onset of depigmentation around the halo nevus (HN) to complete resolution of the nevus and halo has not been well studied.We sought to better understand the natural history of the HN.A retrospective chart review of patients with a clinical diagnosis of HN selected from a private practice database (1994-2010) was performed. In all, 52 patients with 80 HN were identified. The current stage of the HN was determined by a follow-up questionnaire and physical examination of 36 patients with 56 HN.Seven HN were excised. Of the remaining 49 HN, 51% (25) demonstrated no change in the halo or nevus after an average of 4.2 years; 14.3% (7) demonstrated partial nevus regression with persistence of the halo after an average of 6.7 years; 4.1% (2) demonstrated complete involution of the nevus with persistent halo depigmentation after an average of 7.7 years; 8.2% (4) demonstrated complete nevus involution with some repigmentation of the halo after an average of 11.8 years; 22.4% (11) demonstrated complete resolution of the nevus with complete repigmentation of the halo after an average of 7.8 years.Some subjects were lost to follow-up. The time of initial HN onset was dependent on patient recall.These results demonstrate that HN typically persist for a decade or longer. A subgroup may progress through stages of involution with a return to normal-appearing skin, but even these lesions persisted for an average of 7.8 years. Education about the prolonged natural history of HN may reassure patients and avoid unnecessary excision.