Incontinentia pigmenti is probably inherited as an x-linked dominant trait that is usually lethal in males.
Classically, there are vesicles and bullae on an erythematous base, arranged in a linear pattern along Blashko's lines. These vesicles are superseded by red, often warty papules and plaques which, in turn, are supplanted by brown lentiginous lesions in a similar pattern.
All stages can be present simultaneously.
A peripheral eosinophilia is common in the inflammatory stages.
There are often associated dental, ocular and CNS defects.