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.