PIGMENTED SKIN LESIONS IN CHILDREN: CONGENITAL MELANOCYTIC NEVUS, PEDIATRIC LONGITUDINAL MELANONYCHIA, AND PEDIATRIC MELANOMA

Abstract

Background: Considering childhood is a prime period for nevogenesis and given the ectodermal origin of melanocytes and neural tissues, congenital or early-onset nevi might be associated with neurological and developmental disorders later in life. Methods: This was a population-based cohort study retrieving electronic health records from a United States claims database. Pediatric patients (under 18 years) with at least 1 diagnosis of CMN before 3 years of age were included. Unexposed controls were individuals who had encountered health services before 3 years of age without any recording of the aforementioned diagnosis; these were matched for demographics using a 1:1 propensity score matching method. The primary composite outcome was the incidence of subsequently documented neurological and developmental diagnoses, including CNS cancers, seizures, hydrocephalus, cerebral palsy, developmental (speech/learning/motor) delay, attention-deficit hyperactivity disorder, autism spectrum disorder, and intellectual disability. The secondary outcomes included individual components of the primary composite outcome. Results: A total of 30,021 patients with CMN and 2,113,232 unexposed controls were identified, with 30,005 participants after matching in both groups. Individuals with early-onset melanocytic nevi exhibited significantly higher risks of new-onset neurological and developmental diagnoses (HR = 1.43; 95% CI = 1.39-1.48; p 0.001), including hydrocephalus (HR = 1.50; 95% CI = 1.07-2.11; p = 0.019), developmental speech/learning/motor delay (HR = 1.59; 95% CI = 1.31-1.92; p 0.001), autism spectrum disorder (HR = 1.13; 95% CI = 1.02-1.25; p = 0.016), and intellectual disability (HR = 1.31; 95% CI = 1.02-1.68; p = 0.034). After Benjamini-Hochberg correction, the primary composite outcome, hydrocephalus, developmental speech/learning/motor delay, and autism spectrum disorder remained statistically significant. Conclusion: Our findings identify an association of neurologic and developmental disease and the diagnosis of nevi in early childhood (before age 3 years), which provides new information regarding potential comorbid diagnoses, rationale for screening in clinical practice, and important signals for further study.