Histopathological differences between vitiligo and lichen sclerosus et atrophicus using quantitative immunohistochemical analysis

Abstract

IntroductionLichen sclerosus et atrophicus (LS) is rare skin condition characterized by the presence of whitish patches primarily affecting the genital and perianal areas, though it can occur other parts of the body. LS may result in skin depigmentation without textural changes and should be differentiated from vitiligo. However, the histopathological features of hypopigmentation during vitiligo and LS have rarely been compared and have not been precisely described using quantitative immunohistochemical analysis. This study, therefore, aimed to investigate and compare the pigmentary characteristics of LS and vitiligo lesions using histochemical and immunohistochemical staining.MethodsWe included 31 and 46 patients diagnosed with LS and vitiligo, respectively, at Ajou University Hospital between March 2009 and March 2020 in this study. Their medical charts and skin biopsy specimens were retrospectively reviewed. Additionally, Fontana–Masson staining for melanin and immunohistochemical staining for Melan-A, NKI/beteb, tyrosinase, and microphthalmia-associated transcription factor was performed.ResultsThe melanin content, as well as the number of melanocytes was, in general, significantly higher in the epidermis of patients in the LS group compared with that in the vitiligo group. However, 22.6% of LS tissues showed less melanin pigmentation, 25.8% of LS specimens exhibited a lower number of melanocytes, and 29.0% of LS specimens demonstrated less melanocyte activity when compared with the average of vitiligo specimens.ConclusionAs lower melanin pigmentation and the near absence number of melanocytes were also observed in several LS specimens, both the clinical and histological findings must be comprehensively reviewed to differentiate vitiligo from LS.

Lichen sclerosus of the eyelid involving the eyelash margin

“… 2 Ophthalmic manifestations of lichen sclerosus have included lid notching, ectropion, acquired Brown syndrome, and associated keratoconjunctivitis sicca. 7 , 8 , 9 To our knowledge, there are 7 documented cases of extragenital lichen sclerosus affecting the eyelid in medical literature. 2 , 3 , 6 , 7 , 10 , 11 , 12 This is believed to be a novel and rare documented report of a patient with extragenital lichen sclerosus affecting the adnexa of the eye with eyelid and eyelash margin involvement.…”

“…However, histopathological examination can reveal characteristic findings of lichen sclerosus, such as epidermal thinning, basal cell degeneration, and a lichenoid inflammatory infiltrate. 9 It is important to distinguish lichen sclerosus from other conditions as some of them can have notable morbidity and/or mortality. For example, systemic sclerosus has the highest disease‐specific mortality among autoimmune connective tissue disorders.…”

“…Lichen sclerosus typically shows alterations in the expression of certain proteins compared to vitiligo, such as increased expression of certain markers associated with inflammation and tissue damage, whereas vitiligo may show alterations in melanocyte‐related proteins. 9 Clinically, LS often presents with white, atrophic, and sometimes wrinkled patches, commonly affecting genital or perianal regions, but also extragenital areas. Vitiligo, on the contrary, typically presents as depigmented macules or patches on various body surfaces, with a tendency to involve areas exposed to friction or trauma.…”

“…Vitiligo, on the contrary, typically presents as depigmented macules or patches on various body surfaces, with a tendency to involve areas exposed to friction or trauma. 9 LS may also present with symptoms of itching, pain, or discomfort, which are not typically associated with vitiligo.…”