Incontinentia Pigmenti

IP is an X-linked Dominant genodermatosis noted by abnormalities in multiple organ systems.  It got its name from the whorled, irregular distribution of pigment in Blaschko's lines.  It is almost exclusively represented in females, being considered commonly a fatal mutation in males, with the exception of XXY Klinefelter's Syndrome males.  It is considered one of the ectodermal dysplasias, and thus will have many of the manifestations of ectodermal dysplasias.  Weirdly, they have a defective X-inactivation system, which causes both normal genetic expression and mutated genetic expression to occur at the same time in the same individual.

The lesions begin as vesiculobullous lesions, progress to verrucous linear and whorled plaques, progress to hyperpigmentation and then eventually they fade, often to hypopigmentation and atrophy.  Occasionally, these women may not know the diagnosis, and with the extremely subtle findings of some IP adult patients, the only clue may be multiple spontaneous abortions (presumably of male babies). 

As with many ectodermal dysplasias, they can have associated hair, nail, ocular or dental abnormalities, as well as neurologic abnormalities including seizures and mental retardation.

In contradistinction to the group of epidermal nevus syndromes, the lesions of IP are more swirled, and instead of being raised they tend to be flat or atrophic.