- X-linked dominant inheritance
- IKBKG/NEMO gene (encodes a kappa light polypeptide gene enhancer in B cells, kinase gamma, which has a key role in the modulation of nuclear transcription factor kappa B (NF-κB)
Incontinentia pigmenti was described by Bloch in 1926 and Sulzberger in 1928 and is hence also known as Bloch–Sulzberger syndrome.
Skin lesions:Presenting manifestation appear at birth or in first 2 weeks of life, progress over a period of years, and are distributed along the Blaschko lines across 4 classic stages (not all patients experience the 4 stages, and the first 3 can appear simultaneously)
- Stage I | Vesicobullous stage:
- Blistering (birth to age ~4 months)
- Stage II | Verrucous/hyperkeratotic stage (70% cases):
- Wart-like rash (for several months)
- Stage III | Hyperpigmented stage (98% cases, HALLMARK):
- Swirling macular hyperpigmentation (~6 months into adulthood)
- The term incontinentia pigmenti is linked to the histologic characteristics of the lesions in stage 3 of the disease (hyperpigmentation) and specifically to melanin incontinence from melanocytes in the basal epidermal layer and deposits in the superficial dermis.
- Stage IV | Atrophic/hypopigmented stage: Linear hypopigmentation
Other cutaneous manifestations (28-38% cases):
- Dystrophic nails
- Abnormal tooth shape
Neurologic manifestations (30% cases):
- Tonic or focal clonic seizures (M/C): Last for a short time, and cause loss of consciousness
- Other disorders: Microcephaly, ischemic stroke, cerebellar ataxia, and delayed psychomotor development.
Eye impairment:50-77% cases
- Retinal detachment and avascular retina (M/feared complications)
- Other complications: Leukocoria, strabismus, intraocular calcification
Optical coherence tomography (OCT):
- Internal and external retinal layer thinning
- Stage I: Multiple infections of the newborn: Congenital herpes simplex, varicella, epidermolysis bullosa, and bullous pemphigoid
- Stage II: Linear epidermal nevus
- Stage III: Linear & whorled nevoid hypermelanosis
- Stage IV: Hypomelanosis of Ito or vitiligo
Cutaneous manifestations:Cutaneous manifestations of IP do not require specific treatment, since spontaneous resolution of the lesions usually occurs.
- Topical steroids: diflucortolone valerate/chlorquinaldol
Retinal complications:Treatments targeting retinal neovascularization
- Laser photocoagulation
- Vascular endothelial growth factor (VEGF) inhibitors