|LETTER TO THE EDITOR
|Year : 2017 | Volume
| Issue : 1 | Page : 23-25
Extragenital lichen sclerosus et atrophicus in a girl along the lines of Blaschko
Pragya A Nair1, Nidhi B Jivani1, Keyuri B Patel2
1 Department of Dermatology and Venereology, Pramukhswami Medical College, Karamsad, Gujarat, India
2 Department of Pathology, Pramukhswami Medical College, Karamsad, Gujarat, India
|Date of Submission||27-Jul-2016|
|Date of Acceptance||12-Dec-2016|
|Date of Web Publication||2-Jun-2017|
Pragya A Nair
Department of Dermatology and Venereology, Pramukhswami Medical College, Karamsad, Gujarat - 388 325
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Nair PA, Jivani NB, Patel KB. Extragenital lichen sclerosus et atrophicus in a girl along the lines of Blaschko. Egypt J Dermatol Venerol 2017;37:23-5
|How to cite this URL:|
Nair PA, Jivani NB, Patel KB. Extragenital lichen sclerosus et atrophicus in a girl along the lines of Blaschko. Egypt J Dermatol Venerol [serial online] 2017 [cited 2017 Sep 23];37:23-5. Available from: http://www.ejdv.eg.net/text.asp?2017/37/1/23/207496
A 14-year-old girl presented with an asymptomatic lesion over her right shoulder and arm almost 2 years ago. There was no history of trauma, itching, or pain at the site. There was no significant family or past history of the lesion. On examination, multiple atrophic hypopigmented to depigmented macules, papules with follicular plugging, and hyperpigmented scaly plaque were found to be present over the right shoulder ([Figure 1]a and [Figure 1]b). A few comedone-like lesions were also present. Furthermore, hypopigmented scaly macules and papules extending to the upper arm along the lines of Blaschko ([Figure 1]c) were seen. There were no signs of orogenital involvement. All the routine investigations were normal. Wood’s lamp examination showed no fluorescence or accentuation, ruling out the possibility of tinea versicolor and previtiligo. Two biopsies were taken, one from the hypopigmented macule with comedone plug and the other from the hyperpigmented plaque. Lichen striates, nevus comedonicus, guttate morphea, and lichen sclerosus et atrophicus (LSA) were kept as differentials. Histopathology from the comedone plugs showed enlarged follicular opening plugged with keratin and sclerosis with inflammatory infiltrates comprising lymphocytes and plasma cells around the adnexal structure in deep dermis ([Figure 2]a). Biopsy from the hyperpigmented plaque showed thinning of epidermis with follicular cyst formation filled with keratin. Superficial dermis showed edema with occasional hemosiderin-laden macrophages, increased collagen fibers, and lymphoplasmacytic infiltrates with occasional hairshafts. No appendageal structures were seen in deep dermis ([Figure 2]b). Changes were consistent with a diagnosis of LSA. The patient was advised to apply clobetasone butyrate cream in the morning and tacrolimus (0.03%) cream at night along with a moisturizer. On follow-up after 1 month, the lesions regressed in terms of morphology.
|Figure 1: (a) Multiple hypopigmented to depigmented atrophic macules over right shoulder. (b) Follicular plugging and hyperpigmented scaly plaque over right shoulder. (c) Hypopigmented scaly macules and papules over the upper arm along the lines of Blaschko.|
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|Figure 2: (a) Enlarged follicular opening plugged with keratin and sclerosis with inflammatory infiltrates comprising lymphocytes and plasma cells around the adnexal structure in deep dermis. (b) Thinning of the epidermis with follicular cyst formation filled with keratin. H&E, ×10.|
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Lichen sclerosus (LS), originally described by Hallopeau in 1887, is a relatively rare chronic inflammatory dermatosis of an unknown etiology commonly affecting the genital areas with a worldwide prevalence of 0.03% . Extragenital involvement is associated with classic genital LSA in 15–20% of patients and only 2.5% patients show exclusive involvement of extragenital site, as seen in our case . It usually presents as asymptomatic flat, white, polygonal papules and atrophic white plaques . The surface of the lesions show prominent dilated pilosebaceous or sweat duct orifices that contain yellow or brown horny plugs, but may present with solitary hyperpigmented hyperkeratotic plaque with well-defined hypopigmented margins , as was seen in our case. Common extragenital sites are trunk, sites of pressure, upper back, wrists, buttocks, and thighs.
Autoimmune, genetic, infective, hormonal, and local factors have been implicated as proposed etiology. Familial cases showed association with human leukocyte antigen class II antigen DQ7. It has a bimodal peak affecting women in the fifth or sixth decade of life and prepubertal girls with male to female ratio of 1 : 6 . It is relatively uncommon in adult women, rare in men and girls, and extremely rare in boys.
The lines of Blaschko represent a pattern assumed by many different nevoid and acquired skin diseases of the human skin and mucosa-like epidermal nevus, and Darier’s disease . In disorders that affect skin areas corresponding to the lines of Blaschko, it is believed that two distinct cell clones arise early in embryogenesis, often produced as a result of genetic mosaicism.
The lesions follow the lines of Blaschko, which are seen as an inverted ‘U’ shape from the breast/back area onto the upper arm, and perpendicular lines down the front and back of the lower extremities . The mechanism behind the appearance of dermatosis along the lines of Blaschko is unclear. Jackson  suggested that their localization is partly determined by the dermal tissue. The clinical types of extragenital LS include an extensive bullous form, annular, blaschkoid, and keratotic variants . Our patient presented with the blaschkoid pattern over her shoulder extending to the right arm unilaterally.
Linear extragenital LS represents an exceptionally rare form of LS ,.
It is speculated that the cellular immune responsiveness might influence the confinement of the Blaschko-linear LS to the left side of the body , which was seen in our patient, but was affecting the right side.
Biopsy is indicated with pigmented areas in between the lesions to exclude an abnormal melanocytic proliferation. Histologically, LSA has a characteristic pattern with hyperkeratosis, follicular occlusion, thinning of the epidermis, and vascular alterations in the basal layer. A large area of the subepidermal edema with homogenization of collagen, sclerosis, and dilation of the small vessels with hemorrhage and diffuse perivascular infiltrate of lymphocytes was seen in the dermis . Comedo-like plugs on the surface of the plaque correspond to dilated appendageal ostia corroborated by the histology of follicular plugging, as appreciated in our case.
Treatment modality includes topical corticosteroids, testosterone, retinoids, tacrolimus or pimecrolimus, and antimalarial agents . Both UVA1 and NBUVB increase the matrix-metalloproteinase levels in human skin and cultured dermal fibroblasts, which explains the effectiveness of UVA in sclerosing skin diseases. NBUVB has both anti-inflammatory and immunosuppressive effects. As the lesions were localized in our case, the patient was prescribed only potent topical corticosteroid with an advice to follow-up regularly.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]