Extragenital Lichen Sclerosus et Atrophicus.

Lichen sclerosus et atrophicus (LSA) is a chronic inflammatory dermatosis with anogenital and extragenital presentations. Extragenital lichen sclerosus is most common on the neck, shoulders and upper trunk. Linear lesions are uncommon in LSA. We report a case of linear extragenital LSA involving forehead and scalp, along with grouped white papules of LSA in the right side of the back in a postmenopausal woman. The patient showed atypical clinical presentation of LSA in face which clinically mimicked 'en coup de sabre' as seen in morphea, but other clinical features suggested the diagnosis of LSA and the histopathological findings confirmed it.

What was known?

Extragenital LSA is not uncommon, but linear LSA is quite rare. The relationship between LSA and morphea is controversial, and histopathological findings are crucial for the diagnosis. Close follow up of patients is needed as reports of transition of LSA to localized scleroderma and vice-versa on sequential biopsies have been reported.

Introduction

Lichen sclerosus et atrophicus (LSA), described originally by Hallopeau in 1887, is a benign chronic inflammatory dermatosis of unclear pathogenesis and affecting both the epidermis and the dermis.[1] Typical findings are white opalescent papules that may cluster and progressively result in parchment-like skin. LSA occurs mostly in the anogenital area (83% to 98%), and sometimes extragenital sites (15% to 20%).[23] It primarily affects the vulval, perineal and perianal skin of prepubertal, perimenopausal and postmenopausal women. However, extragenital LSA is not uncommon and it was found in 805 of 5207 cases reviewed by Meffert et al.[1] Extragenital LSA found to be relatively common on the neck, shoulder and upper trunk, is generally asymptomatic, but can occasionally be pruritic. Less common sites include the palms, soles, scalp and face. Extragenital LSA is commonly seen in association with plaque type morphea and some authors have suggested a common pathogenesis.[4]

Case Report

A 54-year-old female presented with a single linear vertical hypopigmented plaque in the forehead, starting from the eyebrow level, and extended slowly up to the vertex for last 1 year. After 2 months or so she developed few tiny ivory white macules on the right side of her back. The patient was otherwise healthy, and there was no history of any autoimmune disorders. There was no family history of similar skin diseases. The patient had not undergone any treatment for her skin lesion before she presented to us.

Local cutaneous examination revealed a single linear vertically oriented grayish plaque extending from glabella to vertex, of size 12 cm × 1 cm [Figure 1]. The surface showed wrinkling along with prominent keratin plugs, particularly at its top end [Figure 2]. Induration, minimal scaling and scarring alopecia were present, and no bony depression was found. Examination of the back showed multiple grouped white macules, some of them were perifollicular [Figure 3]. Oral and genital mucosae were normal. Systemic examination failed to show any abnormality. Clinically, linear scleroderma (‘en coup de sabre’) and LSA were considered as differential diagnoses.

Figure 1

Linear vertical grayish plaque

Figure 2

Plaque showing prominent keratin plugs with alopecia

Figure 3

Grouped white macules in back

Complete blood count, routine blood biochemistry, free T4 and TSH, antinuclear antibody (ANA) were within normal limits. X-ray skull, both anteroposterior and lateral views were normal. Histological examination of the biopsy taken from the lesion in forehead and back showed almost similar findings—follicular plugging, thinning of the epidermis, loss of the rete ridges, focal basal cell vacuolization, pigmentary incontinence, edema and hyalinization of the papillary dermis [Figures 4 and 5]. Based on the clinical and histological findings, this case was diagnosed as linear LSA involving face along with extragenital LSA on back. The patient was prescribed topical mometasone furoate 0.1% ointment once daily for 2 months and two intralesional injections of triamcinolone acetonide 10 mg/ml (started concurrently with the ointment) were given into multiple sites at 1 month interval 1 ml (10 mg) in each sitting. The lesion on face was completely flattened and hyperpigmented [Figure 6], and there was slight improvement of the lesions on back. A close follow up was planned.

Figure 4

Histopathology (H and E ×40) shows thinned epidermis, focal basal membrane vacoulization, edema and hyalinization of papillary dermis

Figure 5

Histopathology (H and E, ×10) shows prominent follicular plugging

Figure 6

Post treatment picture shows a flat and hyperpigmented lesion

Discussion

The first case report of linear LSA was described in 1995 by Izumi and Tajima.[5] Thereafter, a handful of cases of linear LSA have been reported, among which some developed in a pattern corresponding to the lines of Blaschko.[67] Ours is a case of linear LSA involving the face and the scalp along with typical LSA lesions in back, without any mucosal lesions. It resembled linear scleroderma (‘en coup de sabre’) quite closely as the middle of the face was involved, but the lesion was slightly to the left of the midline of forehead [Figure 1]. However, distinct follicular plugging, not seen in scleroderma, was noted on close inspection [Figure 2], and the histopathology was consistent with LSA.

The relationship between LSA and morphea is still controversial. Many authors have described coexistent LSA and morphea.[789] With sequential biopsies, several investigators have reported transition from LSA to morphea or vice versa.[49] Nonetheless, other investigators believe there are enough clinical and histological differences between LSA and morphea to argue that they are distinct diseases and those coexistent lesions are coincidental. The therapeutic options for LSA are topical and intralesional corticosteroids, retinoids, phototherapy,[10] estrogen, vitamins, topical tacrolimus and surgical removal, but every option has shown variable and limited responses. In our case, partial improvement was noted with topical steroid ointment for 2 months and monthly intralesional steroid injections for 2 months.

What is new?

Occurrence of extragenital LSA as two forms (linear and grouped macules) in the same patient is extremely rare.