Clinical and histologic features of incontinentia pigmenti in adults with nuclear factor-κB essential modulator gene mutations.

BACKGROUND: Incontinentia pigmenti (IP) is a multisystem disorder, in which cutaneous symptoms can be accompanied by dental, ocular, and central nervous system defects. In adults, the clinical diagnosis of IP is based principally on the late onset of stage 4 lesions and their association with dental, nail, ocular, or central nervous system anomalies. Nevertheless, these lesions are often unrecognized. OBJECTIVES: Our aim was assessment of IP manifestations in adults to clarify diagnostic criteria for mild forms of the disease, to help physicians detect adult IP in the presence of subtle lesions and avoid misdiagnosis. METHOD: We conducted clinical and histologic examination of 25 adults with IP and nuclear factor-κB essential modulator gene rearrangement or mutations. RESULTS: Linear atrophic, hypopigmented, and hairless lesions (stage 4) are constant in adults. Apoptotic keratinocytes in the epidermis or dermis and atrophic hair follicles, with absence of arrector pili muscles, are frequently observed. In contrast, nipple anomalies are rare. LIMITATIONS: We were unable to determine the age of the onset of IP stage 4 lesions. CONCLUSION: Skin manifestations are constant in adult patients with IP. Histology is characteristic and could be considered as a minor diagnostic criterion of IP. Nipple anomalies also may be considered as a minor criterion. Detection of such subtle manifestations can evoke IP in patients with repeated miscarriages or unexplained neurologic manifestations.

Skin biopsy is helpful for the diagnosis of incontinentia pigmenti at late stage (IV): a series of 26 cutaneous biopsies.

BACKGROUND: Hypochromic streaks can be the only cutaneous sign of incontinentia pigmenti (IP) in adulthood (stage IV). Discovery of such lesions in an adult female with no family history of IP is essential for appropriate genetic counselling. OBJECTIVE: To describe and to validate the histological features of residual skin lesions in adult IP. METHODS: The analysis and comparison of skin biopsies of 26 women affected with molecularly confirmed IP. RESULTS: Most biopsies showed slight atrophy and some scattered apoptotic cells in the epidermis, epidermal hypopigmentation and reduced melanocyte number. The dermis appeared thickened and homogeneous and revealed a complete absence of hair follicles (23/26) and sweat glands (22/26). There was no melanin incontinence or inflammatory cells, and the elastic network was normal. CONCLUSION: These features lead unequivocally to the diagnosis of a stage IV IP skin lesion. Consequently, histology is a major confirmatory criterion for diagnoses of these mild clinical forms of IP. It is therefore a useful tool in genetic counselling and prenatal diagnosis. Moreover, the observations described here may contribute to understanding the physiopathology of the late stages of IP.