ABSTRACT
BACKGROUND: Pigmentary mosaicism (PM) is a descriptive term encompassing a range of hyper- and hypo-pigmented phenotypes in various patterns. Information from the neurology literature initially noted neurological abnormalities (NA) in up to 90% of children with PM. The dermatology literature suggests lower associated rates (15%-30%) of NA. Variations in terminology, inclusion criteria, and small population sizes makes interpreting existing PM literature complicated. We aimed to assess rates of NA in children presenting to dermatology with PM. METHODS: We included patients <19 years, diagnosed with PM, nevus depigmentosus and/or segmental café au lait macules (CALM) seen in our dermatology department between 1 January 2006 and 31 December 2020. Patients with neurofibromatosis, McCune-Albright syndrome, and non-segmental CALM were excluded. Data collected included pigmentation, pattern, site(s) affected, presence of seizures, developmental delay, and microcephaly. RESULTS: One hundred fifty patients were included (49.3% female), with a mean age at diagnosis of 4.27 years. Patterns of mosaicism were ascertained for 149 patients and included blaschkolinear (60/149, 40.3%), blocklike (79/149, 53.0%), or a combination of both patterns (10/149, 6.7%). Patients with a combination of patterns were more likely to have NA (p < .01). Overall, 22/149 (14.8%) had NA. Nine out of twenty-two patients with NA had hypopigmented blaschkolinear lesions (40.9%). Patients with ≥4 body sites affected were more likely to have NA (p < .01). DISCUSSION: Overall, our population had low rates of NA in PM patients. A combination of blaschkolinear and blocklike patterns, or ≥4 body sites involved were associated with higher rates of NA.
