Extra genital lichen sclerosus et atrophicus with cutaneous distribution and morphology simulating lichen planus.

Lichen sclerosus et atrophicus (LSA) also known as Csillag's disease, characterized by small, porcelain white, sclerotic areas occur at any site on the skin including mucosa. There is strong association of autoimmune disorders with LSA. Lichen planus (LP) is an inflammatory, papulosquamous disorder characterized by erythematous to violaceous, flat topped, polygonal, pruritic papules distributed mainly on flexural aspects like wrist, around ankles, lumbar region, trunk and neck and also involves mucous membranes, hair, and nail. LP and LSA share similar clinical and pathological features. There have been a few reported cases in the literature of the coexistence of LP and LSA. We reported a case of 39-years-old female having LSA with cutaneous distribution and morphologically simulating LP.

What was Known

Approximately 2.5% of patients of LSA presents with extragenital lesions. There is strong association of autoimmune disorders with LSA and LP.

Introduction

Lichen sclerosus et atprohicus (LSA) also known as Csillag's disease[1] is an uncommon disease of unknown etiology although hereditary, endocrine, and autoimmune factors are known to be involved.[23] It is characterized by small, porcelain white, sclerotic areas occur at any site on the skin including mucosa.[4] Although the anal and genital regions are predominantly affected, 2.5% of patients only present with extragenital lesions particularly of the trunk, neck, and upper limbs. The wrists, palmoplantar region, nipple, and face are less commonly involved.[23] It mainly affects post-menopausal women but can occur in young women. F: M varies from 10:1 to 6:1.[5] LP and LSA share similar clinical and pathological features. There have been a few reported cases in the literature of the coexistence of LP and LSA.[2] We reported a case of 39-years-old female having LSA morphologically simulating LP.

Case Report

A 39-years-old female presented with multiple bilateral symmetrical lesions over extremities, thighs and buttocks since 5 months. Lesions started from lower legs then gradually progressed to involve flexural aspect of forearm, thighs and buttocks. On examination, there were multiple discrete bilateral symmetrical violaceous to hyperpigmented maculo-papular lesions over the above mentioned sites [Figures 1 and 2]. Skin lesions were associated with itching. There was no involvement of the oral and genital mucosa. No evident koebnerization was seen at trauma sites. Skin biopsy was not taken initially because of typical morphology of LP. Clinical diagnosis of lichen planus was made and she was treated with topical application of moderate potent steroid. Within 1 month of treatment new hypo to depigmented macular lesions developed over both dorsum of feet, around ankle, and lower legs [Figure 3]. Wood's lamp examination from the lesions did not show any accentuation. Differential diagnosis LSA, idiopathic guttate hypomelanosis, and pre-vitiligo were kept and skin biopsies were taken from both hyperpigmented as well as hypopigmented lesions. Both biopsy showed an atrophic epidermis, homogenization of the upper dermis and a mid-dermal lymphocytic infiltrate, with flattening of rete ridges which was consistent with lichen sclerosus et atrophicus [Figures 4 and 5].

Figure 1

Violaceous to hyperpigmented maculo-papular lesions over both the forearms

Figure 2

Violaceous to hyperpigmented maculo-papular lesions over both the thigh region

Figure 3

Hypopigmented to depigmented macular lesions over lower leg

Figure 4

Histopathology from hypopigmented lesion. (H&E staining; 100×)

Figure 5

Histopathology from hypopigmented lesion. (H&E staining; 100×)

Discussion

Hallopeau[6] first describe lichen sclerosus in 1887, then Darier[7] reported the histological changes in 1892. They consider the disorder to be a type of lichen planus; other thought that the condition was related to localized scleroderma. But now it is regarded separate entity because of its distinct clinical signs and pathological changes.[4] LSA is chronic inflammatory dermatosis that causes substantial discomfort. There is a strong association with autoimmune disorders, with 21.5 to 34% having it and 74% having autoantibodies. Vitiligo, thyroid, alopecia areata, lichen planus, morphea, pernicious anemia, and SLE are most commonly associated disorders. HLA association with class 2 antigen DQ7 has been demonstrated.[45]

LP is an inflammatory, papulosquamous disorder characterized by erythematous to violaceous, flat topped, polygonal, pruritic papules distributed mainly on flexural aspect like wrist, around ankles, lumbar region, trunk and neck and also involve mucous membranes, hair and nail. As in LSA, immunological mechanism play pivotal role in pathogenesis of LP. Apart from immunological causes infective agent like hepatitis C, drugs and chemicals are involve in its etiology.[5]

LP and LSA share several common features, clinically as well as pathologically, which includes lymphocytic infiltration at the dermal-epidermal junction, clinical involvement of both skin and mucosa, erosive disease of mucosal surfaces and the occasional occurrence of squamous cell carcinoma at the site of chronic, erosive mucosal lesions.[2] Though both conditions have similarities in histopathology, there are few differences. Apart from infiltration there is basal cell degeneration, focal hypergranulosis, flattening of rete ridges, and the presence of civatte bodies in LP.[5]

First-line treatment of LSA includes super-potent topical corticosteroid ointment which has a high response rate. Second-line therapies include topical calcineurin inhibitors. Systemic agents like oral steroids, etretinate, and cyclosporine may be of some benefit.[8] NB-UVB can be used in patient having extra genital LSA.[9] Our patient responded well to potent topical corticosteroids.

In spite of clinical and histological similarities and possible common immunological origin, there are few cases of concurrence of LSA and LP, and LSA simulating LP.[2] Therefore, we reported a case of LSA with cutaneous distribution and morphology simulating lichen planus.

What is new?

Extra genital LSA presenting as a hyperpigmented to violaceous lesions in sites of lichen planus is a rare presentation.