Incontinentia pigmenti 1_0512 Derm Dx
Incontinentia pigmenti 2_0512 Derm Dx
Incontinentia pigmenti 3_0512 Derm Dx
Incontinentia pigmenti 4_0512 Derm Dx
Incontinentia pigmenti 5_0512 Derm Dx
An infant in the pediatric clinic has been exhibiting interesting skin findings. At birth, she had a linear and streaky distribution of vesicles on her trunk and extremities, which subsequently progressed to verrucous plaques at age 2 months and hyperpigmented streaks at age 5 months.
The infant appears to have a small patch of alopecia at the scalp crown. The patient underwent an MRI after birth, which demonstrated that she likely had a small right frontal stroke, but otherwise she is neurologically intact.
An ophthalmologic examination is normal. The patient’s CBC and complete metabolic panel after birth were significant only for a peripheral eosinophilia. An examination of the mother demonstrates pigmented streaks on the trunk and leg (image below).
View the slideshow for images of the patient’s physical exam findings at various time points. What’s your diagnosis?
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Incontinentia pigmenti (IP) is an X-linked dominant genetic disorder caused by mutations in nuclear factor-kappaB essential modulator (NEMO) gene, which is involved in regulating cell proliferation, inflammation and apoptosis. More than 700 cases have been reported.
Patients with IP are predominantly female (97%). IP in males is associated with Klinefelter syndrome or somatic mosaicism. IP affects the skin, teeth, central nervous system (CNS) and eyes.
Cutaneous lesions follow Blaschko’s lines — linear and slightly whorled lines that are believed to trace migration of embryonic cells. Lesions have four distinct stages, which may temporally overlap:
- Stage 1 — vesicular, birth to 2 weeks
- Stage 2 — verrucous, age 2 to 6 weeks
- Stage 3 — hyperpigmented, age 3 to 6 months
- Stage 4 — hypopigmented, age 20 to 30 years
Between 38% and 66% of patients experience cicatricial alopecia. Nail dystrophy occurs in 7% to 51%. Ten percent experience painful subungual tumors, which generally appear in the second or third decade of life.
Other complications include:
- Dental anomalies, including delayed dentition, partial anodontia and pegged teeth in 70% to 95% of patients
- Peripheral eosinophilia lasting four to five months in >70%
- Eye abnormalities, including strabismus, cataracts, optic atrophy and retinal neovascularization in 35%
- CNS involvement (most commonly seizures) in 30%
- Severe neurological complications, such as persistent seizures, stroke, retardation or spasticity in 7.5%
- Blindness in 4% to 8%
Clinical diagnosis is based on the characteristic distribution of vesicles, and the subsequent progression of the lesions through the various aforementioned phases.
Histopathology in the vesicular stage is quite distinctive and consists of eosinophilic spongiosis with intraepidermal vesicle formation and prominent exocytosis of eosinophils.
Treatment and prognosis
Cutaneous lesions require no special therapy and clear spontaneously. Serial ophthalmologic examination is critical to evaluate patients for retinal neovascularization, and determine the appropriate intervention. Dental evaluation should occur at 1 to 2 years, with prosthetics or other interventions as necessary. Consider neurological evaluation at 1 to 2 years, or as needed.
Adam Rees, MD, is a graduate of the University of California Los Angeles School of Medicine and a resident in the Department of Dermatology at Baylor College of Medicine in Houston.
1. Paller AS, Mancini AJ. Hurwitz Clinical Pediatric Dermatology: A Textbook of Skinn Disorders of Chilhood and Adolescence, 4th Edition. 2011:632. Elsevier Saunders; New York.
2. Spitz JL. Genodermatoses: A Clinical Guide to Genetic Skin Disorders. 2004:424. Lippincott Williams & Wilkins; New York.