Diagnosis: Incontinentia pigmenti
Based on the appearance and pattern of the rash and histologic findings, we diagnosed incontinentia pigmenti (IP) in this patient. IP is a rare genodermatosis characterized by abnormalities of the tissues and organs derived from the ectoderm and neuroectoderm. It is a type of ectodermal dysplasia that involves the skin, and sometimes other tissues.1
IP is transmitted in an X-linked dominant manner and occurs predominantly in females; it is often lethal in males. It is caused by a mutation of the IKBKG (inhibitor of kappa B kinase gamma) gene, which results in defective activation of nuclear factor-kappa beta (NF-κB), an essential regulator of inflammatory and apoptotic pathways.1 In females, lyonization results in functional mosaicism of X-linked genes, which is manifested by the Blaschkoid distribution of cutaneous lesions.2
In addition to the skin, IP can also affect the eyes, central nervous system (CNS), teeth, hair, and nails.1 Ocular symptoms are present in 35% to 77% of patients with IP.3 Such symptoms are often unilateral, persistent, and may be highly debilitating. The most serious and by far the most common ocular anomalies affect the retina, with possible development of vascular anomalies, pre-retinal fibrosis, retrolental mass, retinal detachment, and a change in the retinal pigment epithelium. Common non-retinal ocular complications of IP include cataracts and strabismus.