Incontinentia pigmenti: eosinophil chemotactic activity of the crusted scales in the vesiculobullous stage

Incontinentia pigmenti: a review and update on the molecular basis of pathophysiology

Incontinentia pigmenti is an uncommon X-linked dominant disorder, lethal in the majority of affected males in utero and variably expressed in females. Cutaneous manifestations are classically subdivided into 4 stages: vesicular, verrucous, hyperpigmented, and atrophic. Various hair and nail abnormalities, dental anomalies, and ophthalmologic and neurologic deficits are associated with the disorder. The gene for incontinentia pigmenti has been mapped to Xq28. Recently, mutations in the NEMO/IKKgamma gene located at Xq28 have been found to cause expression of the disease. Knockout mice heterozygous for NEMO/IKKgamma gene deficiency develop a clinical phenotype very similar to that of incontinentia pigmenti. NEMO/IKKgamma is an essential component of the newly discovered nuclear factor kappaB (NF-kappaB) signaling pathway. When activated, NF-kappaB controls the expression of multiple genes, including cytokines and chemokines, and protects cells against apoptosis. The mechanism by which NEMO/IKKgamma deficiency causes, via the NF-kappaB pathway, the phenotypical expression of the disease has recently been elucidated. In addition, the newest research findings on eosinophil recruitment through eotaxin release by activated keratinocytes are described in the review. Finally, anhidrotic ectodermal dysplasia with immunodeficiency, a disorder allelic to incontinentia pigmenti, is discussed together with implications on the current understanding of NF-kappaB function. (J Am Acad Dermatol 2002;47:169-87.)

LEARNING OBJECTIVE

At the completion of this learning activity, participants will have a comprehensive and current understanding of incontinentia pigmenti, including its typical and uncommon clinical and histopathologic characteristics, diagnostic assessment, and current management strategies. Additionally, participants will gain the most current knowledge of the genetic and molecular basis of cutaneous pathomechanism.

Expression of eotaxin, an eosinophil-selective chemokine, parallels eosinophil accumulation in the vesiculobullous stage of incontinentia pigmenti

Incontinentia pigmenti (IP) is an X-linked dominant genodermatosis primarily affecting female children. The initial vesiculobullous stage of IP is characterized clinically by inflammatory papules, blisters, and pustules, and histopathologically by acanthosis, keratinocyte necrosis, epidermal spongiosis and massive epidermal eosinophil infiltration. The cause of this multisystem disease is attributed to the mutations of an X-linked regulatory gene, termed nuclear factor-kappaB essential modulator (NEMO). The exact mechanism of epidermal eosinophil accumulation has not yet been determined. We explored the possible role of an eosinophil-selective, nuclear factor-kappaB-activated chemokine, eotaxin, in the accumulation of eosinophils in the initial stage of the disease. Monoclonal antibody (6H9) specific for human eotaxin strongly labelled the suprabasal epidermis of IP skin, paralleling the upper epidermal accumulation of eosinophils, but did not label the epidermis of normal skin or lesional skin from patients with other inflammatory skin diseases not characterized by prominent eosinophil accumulation, namely dermatitis herpetiformis and selected cases of atopic dermatitis lacking significant numbers of eosinophils. In addition, endothelial cells in lesional skin of IP also exhibited strong expression of eotaxin, which correlated with perivascular and intravascular eosinophil infiltration. We also examined the in vitro effects on epidermally derived eotaxin of several cytokines that were nuclear factor-kappaB-activated and/or known to induce eotaxin expression. In normal human keratinocytes, proinflammatory cytokines either independently (IL-1alpha) or synergistically (tumour necrosis factor-alpha (TNF-alpha)/ interferon-gamma (IFN-gamma) and TNF-alpha/IL-4) up-regulated eotaxin expression. These studies suggest that release of cytokines during the initial inflammatory stage of IP induces epidermal expression of eotaxin, which may play a role in the epidermal accumulation of eosinophils.

Extensive vesiculobullous eruption following limited ruby laser treatment for incontinentia pigmenti: a case report

A 3-year-old girl with incontinentia pigmenti was referred for treatment of pigmented whorled macules on the trunk and limbs. Initially ruby laser therapy was only given to the legs. Wound healing was delayed. Two months later the patient developed extensive vesicles and erosions restricted to pigmented macules in both treated and untreated areas. Conservative treatment, including 2 weeks hospitalization, improved acute inflammation, but the remaining pigmentation was darker than originally seen. The apparent reappearance of an early cutaneous manifestation of this syndrome, seemingly triggered by laser therapy, would suggest such treatment is contraindicated.

Eosinophilic and neutrophilic spongiosis: clues to the diagnosis of immunobullous diseases and other inflammatory disorders

When eosinophils or neutrophils are found within the epidermis in concert with edema, the pattern is known as eosinophilic or neutrophilic spongiosis. Although eosinophilic spongiosis has been accepted as a clue to the diagnosis of blistering disorders for some time, the fact that either pattern can serve as a clue to the diagnosis of a variety of disorders, including immunobullous diseases, is less widely known. Herein, we review the types of inflammatory skin diseases, including spongiotic dermatitides, subepidermal vesicular dermatitides, intraepidermal vesicular dermatitides, and perivascular or diffuse dermatitides, that display intraepidermal eosinophils and neutrophils. We also review the known mechanisms that explain in part why intraepidermal granulocytes are commonly found in this diverse group of skin diseases.

Incontinentia pigmenti: late sequelae and genotypic diagnosis: a three-generation study of four patients

Late cutaneous signs of incontinentia pigmenti (IP) are often subtle and misdiagnosed. We focus on these somewhat confusing clinical markers in a family, and on the genotypic diagnosis based on DNA analysis. An infant was born with a typical IP rash. Dermatologic examination of the women in her family revealed that her mother, her maternal aunt, and her grandmother had subtle skin signs reminiscent of IP. The four family members proved to be informative for DNA markers in the Xq28 region. Familial cases of IP are sometimes missed due to the lack of recognition of some late skin signs that are not always hyperpigmented streaks. Subtle, faint, hypochromic or atrophic lesions in a linear pattern may occur. Thus an accurate diagnosis of the women in a particular family also requires anamnestic data and recognition of extracutaneous anomalies. When a clinical diagnosis has been made, DNA marker analysis allows us to offer a prenatal diagnosis with minimal risk of error in case of further pregnancy. However, early testing of chorionic villus samples does not allow one to predict the severity of the disease in an affected fetus.

Incontinentia pigmenti (Bloch-Sulzberger syndrome)

Images

Localization of eosinophil granule major basic protein in incontinentia pigmenti

We report a case of incontinentia pigmenti and demonstrate the deposition and localization of eosinophil major basic protein (MBP) in the vesicular stage of this neurocutaneous syndrome. The initial stage of incontinentia pigmenti is histologically characterized by intraepidermal vesicles associated with eosinophilic spongiotic dermatitis. Pathologic examination of a lesional tissue specimen from our patient demonstrated epidermal necrosis, spongiosis, and vesicle formation. Indirect immunofluorescence with affinity-chromatography purified antibody to human eosinophil granule MBP demonstrated many intact eosinophils within vesicles and scattered throughout the epidermis and dermis, and extracellular deposition of granular MBP in the tissue. The characteristic finding of extensive tissue eosinophilia in incontinentia pigmenti, as well as the new finding of extracellular deposition of an eosinophil granule protein in lesional tissue, suggests the involvement of eosinophils in the pathogenesis of the disease.

Incontinentia pigmenti: XXY male with a family history

We report on the case of a male who from the start of life displayed vesicular lesions; on the trunk these were clustered and on the limbs they adopted a linear configuration. After biopsy of one such lesion, the histopathological study was compatible with a diagnosis of incontinentia pigmenti (IP). In the following months, hyperkeratotic lesions appeared which later became pigmented. The mother and other female members of the family also showed different degrees of alteration related to the same disease. The karyotype study showed the existence of 47,XXY (Klinefelter syndrome). The exceptional nature of this case is that although it is the third case reported in the literature of a male affected by incontinentia pigmenti with a previous family history, it is the only one combining this characteristic with the presence of a 47,XXY karyotype.

Leukocyte chemotactic properties of soluble horny contents in epidermal cysts

Epidermal cysts are one of the most common tumors of the skin. Although asymptomatic ordinarily, they may sometimes become severely inflamed with massive invasion of polymorphonuclear leukocytes (PMN). We studied in vitro PMN chemotactic properties of the aqueous extract prepared from the horny material of epidermal cysts obtained from three patients. A crude aqueous extract of the horny content of the cysts showed PMN chemotactic activity, which, however, was less than that of a horny layer extract prepared from normal skin. Characterization of PMN chemotactic activity using a Sephadex G-75 column showed a peak in the low molecular weight fractions eluting between the vitamin B12 and phenol red markers, which corresponds with the peak of absorbance at 280 nm. The chemotactic substances withstood boiling and trypsin or protease digestion. Although the chemotactic activity was partially ether-extractable, the presence of leukotriene B4 was not demonstrated by radioimmunoassay. In addition to their own chemotactic activity, the horny extracts of epidermal cysts showed cytotaxigenic properties in the presence of fresh serum.