47. Incontinentia Pigmenti
Definition
Incontinentia pigmenti is a rare, X-linked, dominant inherited disorder involving skin pigmentation. Melanin is lost from the basal cells of the epidermis and collects in the dermis as free pigment or as aggregates of melanophages. Incontinentia pigmenti is also known as Bloch-Sulzberger syndrome.
Incidence
The incidence of incontinentia pigmenti is 1:40,000. The disorder is more common among Caucasian populations than other races. It affects females almost exclusively. Male fetuses typically expire in utero, although some do survive. The overall male to female ratio is 1:37.
Etiology
Almost all cases of incontinentia pigmenti occur as the result of a deletion in the NEMO gene; about half are spontaneous mutations.
Signs and Symptoms
Four Stages of Skin Change
1. Vesicular stage: linear vesicles; pustules; bullae with erythema along the lines of Blaschko; present at birth
2. Verrucous stage: warty; keratotic papules and plaques; occurs between 2 and 8 weeks of age
3. Hyperpigmentation stage: macular hyperpigmentation in a swirl pattern along the lines of Blaschko; changes often involve nipples, axilla, and groin; occurs between 12 and 40 weeks of age
4. Hypopigmentation stage: streaks and/or patches of hypopigmentation along with cutaneous atrophy; onset in infancy remaining throughout adulthood
Central Nervous System (10% to 40% of Patients)
• Ataxia
• Hyperactivity
• Mental retardation
• Microcephaly
• Seizures
• Spasticity
• Stroke
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