Incontinentia pigmenti: A failure of immune tolerance?

Abstract

Incontinentia pigmenti is an inherited, largely sex-limited neurocutaneous syndrome characterized by a triphasic cutaneous eruption, dental anomalies, and central nervous system defects. Ocular defects, such as strabismus, blindness, cataracts, microphthalmia, optic atrophy, pseudagliama, and retinal pigmentation, are also common. I The dental anomalies range from mild pegging of some teeth to anodontia. I Either deciduous or permanent teeth may be affected. r The common central nervous system defects include retardation, spastic paralysis, microcephaly, and epilepsy.' The cutaneous eruption is usually present at birth but may develop shortly thereafter as a linear, vesicular eruption that classically evolves over weeks ar months to verrucous and later to hyperpigmented residua. I-3 The lesions usually display a dramatic, whorled configuration. 1-3 All of the cutaneous stigmata may eventually disappear. I Histologically, the vesicular lesions are characterized by eosinophilic spongiosis and a dermal mononuclear infiltrate,4 The verrucous lesions demonstrate hyperkeratosis, acanthosis, papillomatosis, hydropic degeneration of basal cells, and pigmentary incontinence.4 The postinflammatory lesions show a poikiloderma-like epidermal atrophy, basal cell hydropic degeneration, and pigmentary incontinence.4 Incontinentia pigmenti occurs almost exclusively in female individuals. 1,2 In Carney's review l of the world literature, only sixteen of the 653 patients were male. The disease has generally been assumed to represent an X-linked dominant mutation that is lethal in male individuals. 1-3 The relative infrequency of normal male siblings and the increased spontaneous abortion rate in affected families, first emphasized by Lenz,* is consistent