Extragenital Lichen Sclerosus - Morphea Overlap within the Same Lesion: A Rare Occurrence

Dear Editor,

Lichen sclerosus and morphea are both sclerosing disorders that might have a common etiologic link. Although both diseases are considered part of the same disease spectrum because they share few clinical, histopathological, and dermoscopic features, they have subtle differentiating features. Co-occurrence of morphea and lichen sclerosus in the same lesion is rare.[1] Hereby, we are reporting a young male who had features of extragenital lichen sclerosus and morphea within the same lesion.

A 32-year-old male presented with a single depigmented atrophic plaque on the upper back from the past 6 months. There was associated mild lesional pain and it was also associated with stiffness and difficulty in movement of the whole back. Examination revealed a large well-defined plaque of size 10 × 7 cm with three zones on the upper back. The centremost zone had a hyperpigmented hyperkeratotic plaque; this was surrounded by a depigmented ivory white atrophic area with multiple keratotic follicular plugs and the outermost zone had blanchable erythema along with guttate depigmented atrophic macules. There was significant induration on the plaque [Figure 1a]. Dermoscopy revealed multiple keratotic follicular plugs, bright white patches and whitish-yellow structureless areas [Figure 1b using Dermlite 4 in non-polarised mode at 20x magnification]. There were no genital lesions. Patient denied history suggestive of autoimmune connective tissue disorders including photosensitivity, Raynaud’s phenomenon, oral ulcers, binding down of skin or muscle weakness. He also denied presence of any pre-existing autoimmune disorder. Skin biopsy was done from the junction of the hyperkeratosis and ivory white induration including almost half of each side. Histopathology revealed orthokeratosis, follicular plugging and thinned out rete ridges. There was basement membrane thickening and focal basal cell vacuolization [Figure 2]. There was marked edema in papillary dermis. The deeper dermis showed thickened hyalinised collagen and perivascular lympho-histiocytic infiltrate. No significant plasma cells were noted in the infiltrate [Figure 2]. Presence of follicular plugging, porcelain white depigmented atrophic plaque, guttate atrophic depigmented macules, dermoscopic presence of follicular plugging, telangiectasia and histopathological evidence of follicular plugging along with atrophic epidermis and flattened rete ridges indicated towards extragenital LS. Morphea was also considered based on the presence of significant induration, atrophy, and perilesional blanchable erythema. Histopathology also suggested morphea, as the dense homogenization of the collagen was reaching up to the deeper dermis. Based on clinical, dermoscopy, and histopathological findings of both, the diagnosis of extragenital LS - Morphea overlap was considered. Due to the rapidly progressive nature of the disease and associated pain and stiffness of the back leading to difficulty in daily life activities, he was started on once weekly dosage of methotrexate 15 mg along with halobetasol propionate ointment 0.05% once a day application. The patient is currently under our follow-up and has shown good clinical improvement.

Figure 1.

(a) A large well-defined plaque with a central zone of hyperkeratotic plaque which is surrounded by a depigmented induration part with multiple follicular plugs and a surrounding rim of erythema present on the upper back. A round punched-out ulcer is present on the 5 O’clock position, which is indicative of a punch biopsy site. (b) Dermoscopy reveals multiple yellowish-brown keratotic follicular plugs with surrounding scaling (Black arrow), yellowish-white structureless areas morphologically similar to white clouds known as fibrotic beams (black star), bright white patches (red arrow), and multiple linear vessels (Red star) (Dermlite 4 in non-polarised mode at 20× magnification)

Figure 2.

(a) Punch biopsy with box like edges (hematoxylin and eosin, ×20) (b) Epidermis shows striped trilayered appearance with compact orthokeratosis, follicular plugs, thinned out rete ridges with atrophic epidermis and papillary dermal edema (×100) (c) Mid and lower dermis with dense hyalinised collagen bundles and perivascular lymphocytic infiltrate (hematoxylin and eosin, x100) (d) Basement membrane thickening was identified (hematoxylin and eosin, x200) (e) Focal basal layer vacuolation was identified (hematoxylin and eosin, x400) (f) Higher power image of infiltrate, no significant plasma cells were noted (hematoxylin and eosin, x400)

Extragenital LS is a rare inflammatory dermatosis commonly occurring on the upper trunk, shoulders, neck, and proximal extremities. It usually starts as violaceous papules which coalesce to form plaques and later lead to an ivory-white thin atrophic plaque.[1] Plaque morphea commonly presents as round to oval indurated plaques with a rim of erythema in the initial stages which is suggestive of active disease.[2] In the later stages, the central induration expands and leaves behind a depigmented sclerotic plaque with a wrinkled surface. A few authors also suggest lichen sclerosus as a superficial variant of morphea and call it subepidermal morphea.[1] However, the literature also suggests that both are distinct diseases which might have a common etiologic link and there are subtle differences between these two diseases.

LS on histopathology can have prominent epidermal changes including hyperkeratosis, follicular plugging, epidermal atrophy and basal cell vacuolar degeneration. In dermis there is the homogenisation of collagen, which is usually limited to the upper dermis.[1] Morphea on the other hand have either normal or atrophic epidermis and thick collagen bundles leading to dense collagenisation of the dermis that goes deeper to the reticular dermis leading to a squared-off biopsy. There is a dense interstitial inflammatory infiltrate including lymphocytes, eosinophils, plasma cells, and histiocytes, and entrapment of adnexa leading to loss.[1,2]

On dermoscopy, there are subtle changes in LS and morphea. Common findings include structureless white areas suggestive of the sclerosed dermis. However, due to deeper involvement in morphea, these areas are less well defined and opaque than in LS and are called fibrotic beams. LS can show follicular plugs, bright white patches, linear vessels, and hemorrhagic spots.[3]

Features of LS and morphea within the same lesion are rare and have been reported by a few authors.[4–8] Our case had various morphologies within the same lesion—hyperkeratotic center, depigmented indurated area, and the rim of erythema, which was suggestive of both LS and morphea. Both diseases tend to co-exist more frequently than expected and therefore, the index of suspicion should be high in cases that show features of both diseases. Prompt diagnosis and timely initiated management can significantly improve patient outcomes and thus can prevent disease progression.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.