Hyperkeratotic Halo Nevus in Childhood: Three Cases with Standard and UV Dermoscopic Documentation and Narrative Review of the Literature

Introduction: Halo nevus (HN) is a benign melanocytic lesion with a peripheral depigmented halo due to immune-mediated regression. A rare hyperkeratotic pediatric variant may precede halo development, posing a diagnostic challenge. Objectives: To describe the clinical and dermoscopic features of hyperkeratotic halo nevus (HHN) in children. Methods: We performed a narrative literature review and reported a case series of three children evaluated with clinical examination, dermoscopy, and UV dermoscopy. Screening for autoimmune diseases included thyroid function, anti-thyroid antibodies, and celiac serology. Results: Three Caucasian children (mean age 9 years) presented with multiple asymptomatic hyperkeratotic halo nevi, mainly on the trunk (Fitzpatrick II). Diagnosis was based on clinical and dermoscopic findings; biopsy was not required. Thyroid function and celiac serology were unremarkable in all patients, while one patient showed positive anti-thyroid peroxidase antibodies despite normal thyroid function. UV dermoscopy enhanced visualization of perilesional depigmentation and showed increased central reflectance, which we interpreted as a possible keratin-related optical phenomenon. Conclusions: HHN is a rare but benign variant of HN that can be diagnosed clinically when dermoscopic features are reassuring. UV dermoscopy may provide complementary information by enhancing visualization of perilesional depigmentation; the observed increased central reflectance may represent a keratin-related optical phenomenon, although this interpretation requires further validation.