Incontinentia pigmenti (Bloch-Sulzberger syndrome): a systemic disorder

Incontinentia pigmenti (IP) is a rare inherited multisystem disorder characterized by a distinctive swirling pattern of the skin; defects of teeth, hair, and nails; and ophthalmic, central nervous system, and musculoskeletal abnormalities. It progresses through several well-defined stages. IP is transmitted as a dominant X-linked trait with variable expressivity, but many--if not most--cases are sporadic. IP has been shown to result from mutations in the NEMO gene that completely abolish expression of NF-kappaB essential modulator. The diagnosis of IP typically is made based on characteristic clinical findings. Molecular analysis of the NEMO gene is now possible, as is analysis of skewed X-chromosome inactivation, which can further reduce diagnostic confusion. A number of disorders, including hypomelanosis of Ito, should be considered in the differential diagnosis. The considerations vary according to the stage of IP. Careful head-to-toe clinical evaluation is critical in the evaluation of a child with suspected IP given the frequent multisystem involvement. A multidisciplinary approach including dermatology, ophthalmology, neurology, and dental consults is typically warranted. The skin manifestations of IP do not require specific treatment other than reassurance; spontaneous resolution of the lesions usually occurs.