incontinentia

Incontinentia pigmenti, also known as Bloch-Sulzberger syndrome, is a rare X-linked dominant genetic disorder that primarily affects ectodermal tissues, including the skin, dentition, hair, nails, eyes, and the central nervous system. The condition results from mutations in the IKBKG gene (formerly NEMO) on the X chromosome, often a deletion that disrupts gene function. Because it is X-linked dominant, affected females typically survive due to random X-inactivation, while most affected males die in utero or shortly after birth; rare surviving males are usually mosaic or have milder mutations.

The cutaneous presentation is characteristic and progresses through four stages. In infancy, vesicular lesions appear in a swirled pattern; in early childhood, verrucous or warty lesions emerge along Blaschko lines; in later childhood, hyperpigmented swirls follow the same patterns; and in adolescence or adulthood, hypopigmented, atrophic patches may remain. Extracutaneous signs are common and can involve the teeth (notched or peg-shaped incisors, conical canines, premature tooth loss), hair and nail dystrophy, and ocular abnormalities such as strabismus, cataracts, and retinal problems. Neurological involvement may include seizures, developmental delay, cognitive impairment, or other neurologic symptoms.

Diagnosis is clinical, supported by genetic testing that identifies IKBKG mutations. Genetic counseling addresses the X-linked pattern and recurrence risk. Management requires a multidisciplinary approach with dermatology, dentistry, ophthalmology, neurology, and genetics. Skin care in infancy, monitoring and treatment of dental and eye issues, and early developmental support are important. Prognosis varies with the extent of non-cutaneous involvement; with appropriate care, many individuals live into adulthood.