Central nervous system anomalies in 41 Chinese children incontinentia pigmenti

Incontinentia pigmenti (IP) is a rare neuroectodermal dysplasia caused by a defect in the IKBKG gene. The pathogenesis of central nervous system injury is believed to be related to microvascular ischemia. Currently, few treatment strategies are available for the inflammatory phase.

This retrospective descriptive analysis included the clinical data of 41 children with IP collected from 2007 to 2021 in Xi'an, China, comprising clinical characteristics, imaging findings, blood cell analysis, skin histopathology, and genetic data.

Fourteen children (34%) aged 4 days to 5 months exhibited clinical signs and symptoms, including convulsions, delayed psychomotor development following neurological damage, and revealed significant MRI abnormalities, including ischemia, hypoxia, cerebral hypoperfusion, hemorrhage, encephalomalacia, and cerebral atrophy. Eight of the 24 patients (33%) presented with retinal vascular tortuosity and telangiectasis, accompanied by neovascularization and hemorrhage. Thirty-eight children (93%) had elevated eosinophils (mean: 3.63 ± 4.46 × 10⁹), and 28 children (68%) had significantly elevated platelets (mean: 420.16 ± 179.43 × 10⁹). Histopathology of skin revealed microvascular extravasation and vasodilation with perivascular and intravascular eosinophilic infiltration.

Brain injury in IP occurs during infancy until 5 months of age, which is also the acute dermatitis phase accompanied by eosinophilia and an increased platelet count. This study provides evidence of microvascular damage to the skin and fundus during the inflammatory phase. The mechanism of microvascular damage may be similar to that in the brain.