Koebnerization of Lichen Sclerosus Et Atrophicus at Insulin Injection Sites - A Rare Case with Dermoscopic Features.

Lichen sclerosus et atrophicus (LSEA), also known as lichen sclerosus (LS), is a disabling, cosmetically disfiguring condition predominantly affecting the anogenital region of pre- and postmenopausal females. Extragenital LS is relatively less common and occurs predominantly on the trunk and neck. Koebnerization or isomorphic phenomenon is reported occasionally in LS after trauma like radiotherapy. A few case reports describe koebnerization of LS at injection sites. We describe the first such case in India of LS koebnerizing at insulin injection sites with dermoscopic features. Copyright:

Introduction

Lichen sclerosus et atrophicus (LSEA) or lichen sclerosus (LS) is a benign chronic inflammatory dermatosis of unknown etiopathogenesis. It mostly affects prepubertal, perimenopausal, and postmenopausal women.

Extragenital LS occurs in 15–20% cases;[1] involves the neck, shoulder, and upper trunk in the form of porcelain white atrophic macules and plaques; and is generally asymptomatic.

LS exhibits occasional koebnerization[2] due to stimuli like radiotherapy[3] and physical trauma[4] and rarely occurs at injection sites.[56]

Uptil date, there is only a single reported case of LS at sites of insulin injection.[7] We present one such case with dermoscopic and histologic features.

Case History

A 65-year-old women, under treatment for diabetes mellitus with subcutaneous human insulin since the past 2 years, presented with gradual onset tightening of skin of abdominal injection sites with difficulty in injecting insulin since 4–5 months followed by gradual onset white discoloration of those sites since 3 months [Figures 1 and 2]. These were small to begin with otherwise asymptomatic. These lesions gradually extended to the present size. There were no other skin or genital complaints.

Figure 1

Atrophic porcelain white depigmented plaques at insulin injection sites on the abdomen

Figure 2

Close-up view of depigmented porcelain white plaques on the abdomen

Examination revealed indurated well-defined depigmented patches on all four abdominal quadrants. A slightly atrophic surface was noted on closer examination. Dermoscopy (Dinolite video dermoscope, polarized mode) revealed follicular plugging in the form of yellowish plugs, telangiectasias, and whitish patches [Figure 3]. Based on the above findings, we kept our provisional diagnosis as LS.

Figure 3

Polarized dermoscopic image (Dinolite video dermoscope) showing ill-defined whitish patches (*), yellowish follicular plugging £, and telangiectasia (§)

Histopathologic examination of a 4-mm punch biopsy revealed predominantly atrophic epidermis with hyalinization of upper dermis [Figure 4]. Lymphoplasmacytic infiltrate was noted around the dermal vessels [Figure 5] and [Figure 6]. A few dilated lymphatics were noted in the upper dermis [Figure 7]. A definitive diagnosis of LS was arrived via clinicopathologic correlation and dermoscopy.

Figure 4

Hyalinization of upper dermis (Hematoxilin and Eosin [H and E] stain – ×10) magnification (*)

Figure 5

Perivascular lymphoplasmacytic infiltrate (§) (H and E – ×20)

Figure 6

Perivascular lymphoplasmacytic infiltrate (*) (H and E – ×40)

Figure 7

Dilated lymphatic in upper dermis (*) (H and E – ×20)

The patient was asked to stop injecting insulin in the affected areas. We have prescribed 0.1% Mometasone Furoate cream to be applied twice daily and the patient will be followed up monthly.

Discussion

LS is a chronic idiopathic inflammatory skin disease, which is underdiagnosed and undertreated. Prevalence of extragenital disease varies from 15% to 20%.[1] The exact pathogenesis is still a mystery. Immunological changes in T and B lymphocytes have been described. Vulvar LS has raised levels of Th1-specific cytokines, dense T-lymphocyte infiltration, and raised BIC/miR-155 expression and autoantibodies against extracellular matrix protein 1 (ECM-1) and BP180 antigen.[4] Another pathogenic mechanism which may be of relevance in the occasional koebnerization observed in LS[2] secondary to stimuli like radiotherapy[3] and scratching[4] may be altered ECM-1. Supposedly, in vulvar LS, trauma causes altered epitopes in ECM-1 leading to antigen recognition by T cells which leads to formation of antibodies and clinical manifestations of LS.[8] It is unknown if a similar mechanism is operative in koebnerized extragenital LS.

Extragenital LS manifests as atrophic ivory white-porcelain plaques and patches most commonly on the upper trunk, neck, and shoulder.[1]

A few cases of localized or generalized LS with or without morphea have been reported at injection sites.[56]

To the best of our knowledge, only a single case of LS developing at sites of subcutaneous insulin injection has been reported.[7]

Dermoscopic features of LS described in the literature are sparse. Features noted in our patient include white-yellow patches and follicular plugging as described by Errichetti et al.[9]

Other authors have described dermoscopic features including white structureless areas and comedo-like openings.[10] An erythematous halo as marker of disease activity was also described.[11]

The major dermoscopic differential diagnosis of LS mentioned in the literature is morphea. A comparative analysis in this regard has been done by Errichetti et al.[9] Findings of yellow follicular plugs, bright white patches (both noted in the present case), and hemorrhagic spots point toward LS, whereas fibrotic beams and pigmentary structures were commoner in morphea.

Based on the above, we have clinically diagnosed our case as LS, which was corroborated on histopathology. To our knowledge, this represents the second case reported in the literature of LS koebnerizing at sites of subcutanous insulin injection and the first case with dermoscopic documentation of the disease in this rare presentation.

Treatment options for LS[112] include corticosteroids (topical and intralesional), for example, clobetasol propionate ointment, topical calcineurin inhibitors, such as tacrolimus, phototherapy (psoralen + ultraviolet A or plain UV-A1), retinoids, estrogen, etc., but no definite cure apart from surgical excision is known (not feasible nor desirable in this case). As mentioned above, this patient has been advised to stop injecting insulin at these affected sites and 0.1% Mometasone Furoate cream has been prescribed twice daily.

Conclusion

Depigmented atrophic plaques at injection sites could point toward koebnerization of LS. Confirmation of the diagnosis is by biopsy or clinic–pathologic correlation and is supported by dermoscopy. Treatment mandates stopping injection at the affected sites and topical steroids as the mainstay of therapy.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.