Hypochromic reticulated streaks in incontinentia pigmenti: an immunohistochemical and ultrastructural study.

A 25-year-old woman who recently gave birth to a baby affected by classic lesions of incontinentia pigmenti (IP), had hypochromic, atrophic, and reticulated streaks on both lower limbs. Her personal history was unremarkable for IP, and physical examination revealed no other cutaneous signs of the disease. Immunohistochemical and electron microscopic studies were performed on biopsies obtained from both normal and hypochromic skin of the leg. Hypochromic skin showed epidermal atrophy and lack of adnexae, without significant melanocyte abnormality. As demonstrated by this patient, hypochromic reticulated streaks can represent the only cutaneous marker of IP in adulthood. Careful search for such skin lesions in the mother of a child with IP is essential in order to ascertain whether there is a risk of its occurrence in future offspring.