Extracellular matrix protein 1 autoantibodies in male genital lichen sclerosus

EuroGuiderm guideline on lichen sclerosus-introduction into lichen sclerosus

INTRODUCTION

Lichen sclerosus (LS) is an inflammatory skin disease affecting all ages. LS typically involves the anogenital site where it causes itching and soreness. It may lead to sexual and urinary dysfunction in females and males; however, it may be asymptomatic. First signs of LS are redness and oedema, typically followed by whitening of the genital skin; sometimes fissuring, scarring, shrinkage and fusion of structures may follow in its course. LS is associated with an increased risk of genital cancer. LS has a huge impact on the quality of life of affected patients, and it is important to raise more awareness of this not uncommon disease in order to diagnose and treat it early.

OBJECTIVES

The guideline intends to provide guidance on the diagnostic of LS, highlight important aspects in the care of LS patients (part 1), generate recommendations and treatment algorithms (part 2) on topical, interventional and surgical therapy, based on the latest evidence, provide guidance in the management of LS patients during pregnancy, provide guidance for the follow-up of patients with LS and inform about new developments and potential research aspects.

MATERIALS AND METHODS

The guideline was developed in accordance with the EuroGuiDerm Methods Manual v1.3 https://www.edf.one/de/home/Guidelines/EDF-EuroGuiDerm.html. The wording of the recommendations was standardized (as suggested by the GRADE Working Group). The guideline development group is comprised of 34 experts from 16 countries, including 5 patient representatives.

RESULTS

Ultrapotent or potent topical corticosteroids in females and males, adults and children remain gold standard of care for genital LS; co-treatment with emollients is recommended. If standard treatment fails in males, a surgical intervention is recommended, complete circumcision may cure LS in males. UV light treatment is recommended for extragenital LS; however, there is limited scientific evidence. Topical calcineurin inhibitors are second line treatment. Laser treatment, using various wave lengths, is under investigation, and it can currently not be recommended for the treatment of LS. Treatment with biologics is only reported in single cases.

CONCLUSIONS

LS has to be diagnosed and treated as early as possible in order to minimize sequelae like scarring and cancer development. Topical potent and ultrapotent corticosteroids are the gold standard of care; genital LS is often a lifelong disease and needs to be treated long-term.

Lichen sclerosus: The 2023 update

Lichen sclerosus (LS) is an underdiagnosed inflammatory mucocutaneous condition affecting the anogenital areas. Postmenopausal women are predominantly affected and, to a lesser extent, men, prepubertal children, and adolescents. The etiology of LS is still unknown. Hormonal status, frequent trauma and autoimmune diseases are well-known associations for LS, yet infections do not seem to be clear risk factors. LS pathogenesis involves factors such as a genetic predisposition and an immune-mediated Th1-specific IFNγ-induced phenotype. Furthermore, there is a distinct expression of tissue remodeling associated genes as well as microRNAs. Oxidative stress with lipid and DNA peroxidation provides an enabling microenvironment to autoimmunity and carcinogenesis. Circulating IgG autoantibodies against the extracellular matrix protein 1 and hemidesmosome may contribute to the progression of LS or simply represent an epiphenomenon. The typical clinical picture includes chronic whitish atrophic patches along with itching and soreness in the vulvar, perianal and penile regions. In addition to genital scarring, and sexual and urinary dysfunction, LS may also lead to squamous cell carcinoma. Disseminated extragenital LS and oral LS are also reported. The diagnosis is usually clinical; however, a skin biopsy should be performed in case of an unclear clinical picture, treatment failure or suspicion of a neoplasm. The gold-standard therapy is the long-term application of ultrapotent or potent topical corticosteroids and, alternatively, topical calcineurin inhibitors such as pimecrolimus or tacrolimus. Collectively, LS is a common dermatological disease with a so far incompletely understood pathogenesis and only limited treatment options. To foster translational research in LS, we provide here an update on its clinical features, pathogenesis, diagnosis and (emerging) treatment options.

Penile Lichen Sclerosis: A Surgical Perspective of its Aetiology and Treatment

Penile lichen sclerosis is a longstanding inflammatory disease of the skin with a controversial aetiology. Penile lichen sclerosis (PLS) is a growing, inflammatory dermatitis of the anogenital region, which involves the meatus, prepuce, penile shaft, and glans penis. Although the accurate aetiology of PLS is contentious, multiple factors including genetics, autoimmunity, infections of human papillomavirus, hepatitis C, Epstein-Barr virus, risk factors (hormonal and trauma), etc., can be considered to be a part of the etiopathogenesis of PLS. The initial clinical presentations of penile lichen sclerosis are white plaques, atrophied skin, erythema, erosions, and sclerosis in the anogenital region. When the disease advances, the following can occur, including meatal constraints, telangiectasia, petechiae, soreness, papular lesions, tightness of the foreskin, difficulties in passing urine, itching, tenderness on erections, pain, cracking, bleeding, redness, rashes, tightness at frenulum, and dysuria. This disease has a dangerous course of action and if untreated it may be linked with severe urologic and sexual morbidities. PLS is usually treated with medical and surgical interventions like topical or intralesional steroids and circumcision. The role of circumcision is very critical in the course of action and prognosis of PLS, and its treatment is dependent on the stage of the disease. This review brings up the knowledge regarding epidemiology, etiopathology, clinical presentation, and management of PLS with an emphasis on the role of circumcision.

Human beta defensin levels and vaginal microbiome composition in post-menopausal women diagnosed with lichen sclerosus

Human beta defensins (hBDs) may play an important role in the progression of lichen sclerosus (LS), due to their ability to induce excessive stimulation of extracellular matrix synthesis and fibroblast activation. The genetic ability of the individual to produce defensins, the presence of microbes influencing defensin production, and the sensitivity of microbes to defensins together regulate the formation of an ever-changing balance between defensin levels and microbiome composition. We investigated the potential differences in postmenopausal vaginal microbiome composition and vaginal hBD levels in LS patients compared to non-LS controls. LS patients exhibited significantly lower levels of hBD1 (p = 0.0003), and significantly higher levels of hBD2 (p = 0.0359) and hBD3 (p = 0.0002), compared to the control group. The microbiome of the LS patients was dominated by possibly harmful bacteria including Lactobacillus iners, Streptococcus anginosus or Gardnerella vaginalis known to initiate direct or indirect damage by increasing defensin level production. Our observations highlight that correcting the composition of the microbiome may be applicable in supplementary LS therapy by targeting the restoration of the beneficial flora that does not increase hBD2-3 production.

Vulvar Lichen Sclerosus from Pathophysiology to Therapeutic Approaches: Evidence and Prospects

Vulvar lichen sclerosus (VLS) is a chronic, distressing, inflammatory disease with an enormous impact on quality of life. Treatment goals are relieving symptoms, reversing signs and preventing anatomical changes. Despite the availability of numerous therapeutic options, treatment outcome may not be entirely satisfactory and a definitive cure does not exist. This may be due to the fact that the exact VLS etiopathogenesis remains unknown. The objectives of this paper were to review the most up-to-date knowledge on VLS etiopathogenesis and to consider the available therapies through the lens of a plausible pathogenetic model. An electronic search on both VLS etiopathogenesis and its treatment was performed using the National Library of Medicine PubMed database. Based on current knowledge, it is conceivable that various, heterogeneous environmental factors acting on a genetic background trigger an autoimmune, Th-1 response, which leads to a chronic inflammatory state. This, in turn, can determine both tissue and micro-vascular injury and activation of signaling pathways involved in fibroblast and collagen metabolism. This pathogenetic sequence may explain the effectiveness of anti-inflammatory treatments, mostly topical corticosteroids, in improving VLS clinical-pathological changes. Further deepening of the disease pathways will presumably allow key mediators to become new therapeutic targets and optimize the available treatments.

Diagnosis and management of cutaneous and anogenital lichen sclerosus: recommendations from the Italian Society of Dermatology (SIDeMaST)

Lichen sclerosus (LS) is a disabling chronic inflammatory disease of skin and genital mucous membrane causing itch, pain, dysuria and restriction of micturition, and significant sexual dysfunction and dyspareunia both in women and men. If left untreated, LS is associated with a high degree of sclerosis and scarring, as well as with an elevated risk of cancer in the genital area. Although a central role of autoimmunity is suggested, the pathogenesis of LS is still not clearly understood and the disease remains difficult to treat. The goals of treatment of LS are to alleviate symptoms and discomfort, prevent anatomical changes and prevent malignant transformation. This guideline has been developed by an Italian group of experts. It summarizes evidence-based and expert- based recommendations. The highest level of evidence favors the use of topical high potency corticosteroids; second and third lines' treatments include topical calcineurin inhibitors and topical retinoids, respectively. Surgical treatment has become the treatment of choice in male genital LS with persistent phimosis not responsive to medical treatment. The aim of this paper is to offer evidencebased and easily applicable recommendations for the management of LS.

Frontal fibrosing alopecia and genital Lichen sclerosus: Single-center experience

BACKGROUND

Despite the incidence of Frontal fibrosing alopecia (FFA) has been increasing in last two decades, the pathophysiology and trigger factors of FFA have not been yet fully understood.

AIMS

The aim of this study was to describe epidemiology, clinical and trichoscopic features and comorbidities of FFA patients, in order to improve the understanding of this disease.

PATIENTS/METHODS

A retrospective, observational monocentric study was conducted from 2003 to 2019. Data concerning epidemiology (age, gender, age of menopause, and age of FFA onset), comorbidities, current therapies, localization of FFA (such as frontotemporal hairline, occipital, eyebrow, eyelash, beard, sideburns, and body hair), presence of papules and sign of Lichen planus (LP) at skin, mucosae and/or nail were collected for each patient included.

RESULTS

A total of 119 Caucasian, adult patients (8 men and 111 female) with FFA were enrolled in the study. Cutaneous, mucosal, or nail localization of LP were found in 16% of our subjects. Interestingly, 15 out of 119 subjects (10.61%) were affected by concomitant genital Lichen sclerosus (LS) and 5 out of these 15 patients (4.38%) presented both LS and LP in association with FFA.

CONCLUSION

Considering the high prevalence of LS in FFA patients in our case series, and the frequency of autoimmune comorbidities in both LS and FFA, it is possible to hypothesize an autoimmune process in both conditions. Further studies are needed for a better understanding of the nature of the association between LS and FFA.

Anogenital lichen sclerosus

Lichen sclerosus (LS) was first described by Hallopeau in 1887. It is a chronic inflammatory condition most commonly involving the anogenital region with a relapsing course and a potential for destruction, functional impairment, atrophy, and malignant changes. LS affects both sexes with a female preponderance of 5:1. The exact prevalence of the disease is difficult to predict as the lesions are asymptomatic in the initial phase and later when the complications arise patients might visit the surgeon, pediatrician, gynecologist, or urologist. The etiology of LS has a complex interplay of genetic factors, autoimmunity, infections, and trauma. Physical examination to assess the extent of the disease and decide the line of management is the most crucial step in the management. Corticosteroids, calcineurin inhibitor, retinoids, phototherapy, and surgery can be helpful. Self-examination and long-term follow-up are necessary.

Lichen sclerosus: the role of oxidative stress in the pathogenesis of the disease and its possible transformation into carcinoma

Lichen sclerosus (LS) is an autoimmune chronic inflammatory disease usually involving the anogenital skin of both sexes; more rarely LS exclusively involves extragenital areas. As a chronic inflammatory disease, in most cases, LS evolves and progresses causing scleroatrophy of the skin or scars which may cause stenosis in the affected areas. A few LS patients are at risk of developing squamous cell carcinoma in their lifetime, but appropriate long-term treatment diminishes the possibility of a malignant evolution. Oxidative stress (OS) has been proven to play a role not only in the pathogenesis of LS, but also in the development and progression of the disease. OS, by causing DNA damage and lipid peroxidation, contributes directly to the possible malignant transformation of LS. Moreover, the increase in oxidative DNA damage is associated with mutations in tumor suppressor genes. Considering the role that OS plays in LS, therapeutic use of antioxidants appears to be rational and possible, in association with other treatments. Antioxidants would counteract the oxidative DNA damage, which is the most important factor for the progression of LS and its malignant transformation.

Lichen Sclerosus: An autoimmunopathogenic and genomic enigma with emerging genetic and immune targets

Lichen sclerosus (LS) is an inflammatory dermatosis with a predilection for anogenital skin. Developing lesions lead to vulvar pain and sexual dysfunction, with a significant loss of structural anatomical architecture, sclerosis, and increased risk of malignancy. Onset may occur at any age in both sexes, but typically affects more females than males, presenting in a bimodal fashion among pre-pubertal children and middle-aged adults. A definitive cure remains elusive as the exact pathogenesis of LS remains unknown. A general review of LS, histologic challenges, along with amounting support for LS as an autoimmune disease with preference for a T_h1 immune response against a genetic background is summarized. In addition to the classically referenced ECM1 (extracellular matrix protein 1), a following discussion of other immune and genetic targets more recently implicated as causative or accelerant agents of disease, particularly miR-155, downstream targets of ECM1, galectin-7, p53, and epigenetic modifications to CDKN2A, are addressed from the viewpoint of their involvement in three different, but interconnected aspects of LS pathology. Collectively, these emerging targets serve not only as inherently potential therapeutic targets for treatment, but may also provide further insight into this debilitating and cryptic disease.

Dermoscopy is a new diagnostic tool in diagnosis of common hypopigmented macular disease: A descriptive study

One of the most frequent complaints in dermatology clinics is the eruption of hypopigmented patchy skin lesions. The aim of the study was to investigate the utility of dermoscopy in common hypopigmented macular diseases. Patients with the followings diseases were examined by dermoscopy: vitiligo, pityriasis alba, nevus depigmentosus, achromic pityriasis versicolor, idiopathic guttate hypomelanosis, and extragenital guttate lichen sclerosus.

This study showed that these hypopigmented macular diseases might display specific dermoscopic features. In vitiligo, the mean dermoscopic features were the presence of a diffuse white glow with perifollicular pigment, perilesional hyperpigmentation, leukotrichia and the pigmentary network. In idiopathic guttate hypomelanosis, the characteristic features were the presence of multiple, shiny, scaly macules with welland ill-defined edges borders that coalesced into polycyclic macules. For nevus depigmentosus, the mean features were hypopigmented patches with irregular border with a faint reticular network. For pityriasis alba, the fairly ill-demarcated hypopigmented macules with fine scales were the mean feature. In lichen sclerosus, there were white structureless areas, perilesional erythematous halo, follicular plugging and white chrysalis like structures. Dermoscopy of achromic pityriasis versicolor showed a fairly demarcated white area with fine scales localized in the skin creases.

Genital Lichen Sclerosus in Male Patients: A New Treatment with Polydeoxyribonucleotide

Lichen sclerosus (LS) is an inflammatory and chronic disease that causes itching, pain, dysuria, urinary retention, dyspareunia and sexual dysfunction, in both men and women. The first line pharmacological treatment is based on the use of topical steroids, which have proved their efficacy in 60-70% of cases but with a high rate of relapses in time (50-80% of the patients of both sexes). The purpose of our non-randomised prospective pilot study was to evaluate the efficacy and tolerability of a new loco regional therapy with polydeoxyribonucleotides (PDRN) in the treatment of male genital LS. PDRN is an healing and anti-dystrophic drug with anti-inflammatory effects, through the reduction of cytokine. Twenty one male patients suffering from genital LS were recruited. All the patients were submitted to treatment using loco-regional intradermal injections with PDRN. Dermatology Life Quality Index (DLQI), International Index of Erectile Function (IIEF-5) and PGI-I questionnaires were administered at baseline and at the end of treatment in order to evaluate the results of this treatment. The statistical evaluation of the data obtained with the DLQI questionnaire showed a marked improvement of the overall conditions in terms of quality of life, with an average change of scores from 15 to 4 (p < 0.0001). PGI-I questionnaire showed that 80% of the patients treated considered their post-treatment conditions as 'improved'. There was no significant change in terms of sexual function according to the IIEF questionnaire (p = 0.189). The results obtained show the excellent tolerability and the therapeutic efficacy of PDRN, with clear improvement of the local symptoms and of the quality of life.

Recent advances in understanding urethral lichen sclerosus

Lichen sclerosus affecting the male genitalia is a poorly understood but potentially devastating condition. The natural history of the condition is beginning to be understood better with longer follow-up of patients. Recent long-term data suggest that circumcision for lichen sclerosus limited to the prepuce may not be curative as was once thought. In addition, surgical treatments should be followed up for longer periods as recurrences may occur after urethroplasty and perineal urethrostomy.

Evidence-based (S3) Guideline on (anogenital) Lichen sclerosus

Lichen sclerosus (LS) is an inflammatory skin disease that usually involves the anogenital area. All patients with symptoms or signs suspicious of lichen sclerosus should be seen at least once initially by a physician with a special interest in the disease in order to avoid delay in diagnosis, as early treatment may cure the disease in some and reduce or prevent scarring. The diagnosis is made clinically in most cases. Biopsies should only be performed under certain circumstances. The gold standard for treatment remains potent to very potent topical steroids; however, mild and moderate disease in boys and men may be cured by circumcision. Certain triggers should be avoided. http://www.euroderm.org/images/stories/guidelines/2014/S3-Guideline-on-Lichen-sclerosus.pdf http://www.awmf.org/fachgesellschaften/mitgliedsgesellschaften/visitenkarte/fg/deutsche-gesellschaft-fuer-gynaekologie-und-geburtshilfe-dggg.html.

Male genital lichen sclerosus

Male genital lichen sclerosus (MGLSc) is a chronic inflammatory skin disease responsible for male sexual dyspareunia and urological morbidity. An afeared complication is squamous cell carcinoma (SCC) of the penis. The precise etiopathogenesis of MGLSc remains controversial although genetic, autoimmune and infective (such as human papillomavirus (HPV) hepatitis C (HCV), Epstein-Barr virus (EBV) and Borrelia) factors have been implicated: Consideration of all the evidence suggests that chronic exposure of susceptible epithelium to urinary occlusion by the foreskin seems the most likely pathomechanism. The mainstay of treatment is topical ultrapotent corticosteroid therapy. Surgery is indicated for cases unresponsive to topical corticosteroid therapy, phimosis, meatal stenosis, urethral stricture, carcinoma in situ (CIS) and squamous cell carcinoma.

Scanning electron microscopy of lichen sclerosus

Lichen sclerosus is an acquired inflammatory condition characterized by whitish fibrotic plaques, with a predilection for the genital skin. We performed scanning electron microscopy of the dermis from a lesion of lichen sclerosus. Normal collagen fibers could be easily found in deeper layers of the specimen, as well as the transition to pathologic area, which seems homogenized. With higher magnifications in this transitional area collagen fibers are adherent to each other, and with very high magnifications a pearl chain aspect became evident along the collagen fibers. In the superficial dermis this homogenization is even more evident, collagen fibers are packed together and round structures are also observed. Rupture of collagen fibers and inflammatory cells were not found. These autoimmune changes of the extracellular matrix lead to the aggregation of immune complexes and/or changed matrix proteins along the collagen fibers, the reason why they seem hyalinized when examined by light microscopy.

[Urological dermatosis]

Urologists are often confronted with venereal and dermatological diseases during clinical evaluation of the external genitals. Dermatosis of the male genitalia ranges from infectious (viral and bacterial) lesions and inflammatory conditions to neoplastic alterations. There are also more general skin diseases (e.g. psoriasis) which occur as genital manifestations. In this case they often show unusual characteristics or the genitalia might be involved only incidentally. This review highlights the clinical diagnosis and therapy of the most common genital skin disorders and demonstrates the medical features.

Fibrosing connective tissue disorders of the skin: molecular similarities and distinctions

A variety of fibrosing connective tissue disorders of the skin have been described. They all share a characteristic activation of fibroblasts resulting in excessive production and deposition of extracellular matrix whereas their etiologies, incidence rates and clinical appearances differ dramatically in part. As effective treatment options are still not on hand, the understanding of cutaneous fibrogenesis needs to be improved. This review focuses on the molecular differences and similarities of the major fibrosing skin disorders namely systemic sclerosis, localized scleroderma, keloid and hypertrophic scars, Eosinophilic fasciitis, Lichen sclerosus and graft-versus-host-disease. Abnormalities in ECM turnover and the impact of matrix-metalloproteases were closely examined. It could be concluded, that besides increased collagen synthesis, modified ECM degradation is an as important factor in cutaneous fibrogenesis. The influence of immune components such as HLA haplotypes and the production of auto-antibodies is crucial for some of the diseases, but not decisive for skin fibrosis in general. A great number of cytokines was reported to be differentially regulated in the respective disorders among whom the components of the gp130/STAT3 signaling pathway seem to be of pivotal importance. Furthermore, the role of miRNAs in the pathogenesis of fibrosing connective tissue diseases of the skin was analyzed according to the current state of knowledge. In summary, this review gives an explicit overview of the various molecular mechanisms leading to fibrosis in the skin and the underlying connective tissue and reveals the most promising targets for future therapeutic approaches.

Diagnosis and treatment of lichen sclerosus: an update

Lichen sclerosus (LS) is a chronic, inflammatory, mucocutaneous disorder of genital and extragenital skin. LS is a debilitating disease, causing itch, pain, dysuria and restriction of micturition, dyspareunia, and significant sexual dysfunction in women and men. Many findings obtained in recent years point more and more towards an autoimmune-induced disease in genetically predisposed patients and further away from an important impact of hormonal factors. Preceding infections may play a provocative part. The role for Borrelia is still controversial. Trauma and an occlusive moist environment may act as precipitating factors. Potent and ultrapotent topical corticosteroids still head the therapeutic armamentarium. Topical calcineurin inhibitors are discussed as alternatives in the treatment of LS in patients who have failed therapy with ultrapotent corticosteroids, or who have a contraindication for the use of corticosteroids. Topical and systemic retinoids may be useful in selected cases. Phototherapy for extragenital LS and photodynamic therapy for genital LS may be therapeutic options in rare cases refractory to the already mentioned treatment. Surgery is restricted to scarring processes leading to functional impairment. In men, circumcision is effective in the majority of cases, but recurrences are well described. Anogenital LS is associated with an increased risk for squamous cell carcinoma of the vulva or penis. This review updates the epidemiology, clinical presentation, histopathology, pathogenesis, and management of LS of the female and male genitals and extragenital LS in adults and children.

Gene expression profiling in male genital lichen sclerosus

Male genital lichen sclerosus (MGLSc) has a bimodal distribution in boys and men. It is associated with squamous cell carcinoma (SCC). The pathogenesis of MGLSc is unknown. HPV and autoimmune mechanisms have been mooted. Anti extracellular matrix protein (ECM)1 antibodies have been identified in women with GLSc. The gene expression pattern of LSc is unknown. Using DNA microarrays we studied differences in gene expression in healthy and diseased prepuces obtained at circumcision in adult males with MGLSc (n = 4), paediatric LSc (n = 2) and normal healthy paediatric foreskin (n = 4). In adult samples 51 genes with significantly increased expression and 87 genes with significantly reduced expression were identified; paediatric samples revealed 190 genes with significantly increased expression and 148 genes with significantly reduced expression. Concordance of expression profiles between adult and paediatric samples indicates the same disease process. Functional analysis revealed increased expression in the adult and child MGSLc samples in the immune response/cellular defence gene ontology (GO) category and reduced expression in other categories including genes related to squamous cancer. No specific HPV, autoimmune or squamous carcinogenesis-associated gene expression patterns were found. ECM1 and CABLES1 expression were significantly reduced in paediatric and adult samples respectively.

Clinical parameters in male genital lichen sclerosus: a case series of 329 patients

BACKGROUND

  The dermatological aspects of male genital lichen sclerosus (MGLSc) have not received much prominence in the literature. Sexual morbidity appears under-appreciated, the role of histology is unclear, the relative places of topical medical treatment and circumcision are not established, the prognosis for sexual function, urinary function and penis cancer is uncertain and the pathogenesis has not been specifically studied although autoimmunity (as in women) and HPV infection have been mooted.

OBJECTIVE

  To illuminate the above by analysing the clinical parameters of a large series of patients with MGLSc.

METHODS

  A total of 329 patients with a clinical diagnosis of MGLSc were identified retrospectively from a dermatology-centred multidisciplinary setting. Their clinical and histopathological features and outcomes have been abstracted from the records and analysed by simple descriptive statistics.

RESULTS

  The collation and analysis of clinical data derived from the largest series of men with MGLSc ever studied from a dermatological perspective has been achieved. These data allow the conclusions below to be drawn.

CONCLUSIONS

  MGLSc is unequivocally a disease of the uncircumcised male; the adult peak is late in the fourth decade; dyspareunia is a common presenting complaint; non-specific histology requires careful interpretation; most men are either cured by topical treatment with ultrapotent steroid (50-60%) or by circumcision (>75%); effective and definitive management appears to abrogate the risk of developing penile squamous cell carcinoma; urinary contact is implicated in the pathogenesis of MGLSc; HPV infection and autoimmunity seem unimportant.