Prevalence and age distribution of pemphigus and pemphigoid diseases among paediatric patients in Germany

S2k guidelines on diagnosis and treatment of linear IgA dermatosis initiated by the European Academy of Dermatology and Venereology

INTRODUCTION

Linear IgA dermatosis (LAD) is a rare subepidermal autoimmune bullous disease (AIBD) defined by predominant or exclusive immune deposits of immunoglobulin A at the basement membrane zone of skin or mucous membranes. This disorder is a rare, clinically and immunologically heterogeneous disease occurring both in children and in adults. The aim of this project is to present the main clinical features of LAD, to propose a diagnostic algorithm and provide management guidelines based primarily on experts' opinion because of the lack of large methodologically sound clinical studies.

METHODS

These guidelines were initiated by the European Academy of Dermatology and Venereology (EADV) Task Force Autoimmune Bullous Diseases (AIBD). To achieve a broad consensus for these S2k consensus-based guidelines, a total of 29 experts from different countries, both European and non-European, including dermatologists, paediatric dermatologists and paediatricians were invited. All members of the guidelines committee agreed to develop consensus-based (S2k) guidelines. Prior to a first virtual consensus meeting, each of the invited authors elaborated a section of the present guidelines focusing on a selected topic, based on the relevant literature. All drafts were circulated among members of the writing group, and recommendations were discussed and voted during two hybrid consensus meetings.

RESULTS

The guidelines summarizes evidence-based and expert opinion-based recommendations (S2 level) on the diagnosis and treatment of LAD.

CONCLUSION

These guidelines will support dermatologists to improve their knowledge on the diagnosis and management of LAD.

The evolution of Pemphigus publications: A bibliometric analysis with research trends and global productivity

Despite an increase in global research on the subject of Pemphigus, which seriously affects patient health and quality of life, there is no bibliometric research on this subject in literature to date. The aim of this study was to conduct a holistic analysis of scientific articles published on Pemphigus, using bibliometric methods. Articles published on the subject of Pemphigus between 1980 and 2021 were downloaded from the web of science (WoS) database and analyzed using various statistical methods. To determine trend subjects, collaboration between countries, and the most effective studies with citation analyses, visual network maps were obtained with bibliometric analyses. A total of 3034 articles were analyzed. The 3 countries making the greatest contribution to literature were the USA (n:831, 27.3%), Japan (n:402, 13.2%), and Germany (n:221, 7.2%). The 3 most active institutions were Keio University (n:163, 5.3%), Kurume University (n:130, 4.2%) and Tel Aviv University (n:107, 3.5%). The 3 journals publishing the most articles were the British Journal of Dermatology (n: 88), Journal of the American Academy of Dermatology (n:171) and the Journal of Investigative Dermatology (n:143). The 3 leading journals according to the mean number of citations (NC) per article (citation count: CC) were the New England Journal of Medicine (CC:246), the Lancet (CC:143) and the Journal of Cell Biology (CC:133). The author with the most articles published was Hashimoto Takashi (n.168, 5.5%). As a result of cluster analysis, it was seen that 9 different main clusters had been studied on Pemphigus subjects to date (1: desmoglein, 2: paraneoplastic Pemphigus (PNP) - Pemphigus types-desmosome, 3: desmoglein 1 ve 3-autoimmunity, 4: treatment-rituximab, 5: acantholysis-apoptosis, 6: quality of life-remission-relapse, 7: autoantibodies, 8: epidemiology-mortality, 9: corticosteroids). The most commonly studied subjects were determined to be pemphigus vulgaris (PV), pemphigus foliaceus (PF), autoimmunity, rituximab, PNP, desmoglein (desmoglein3-desmoglein1), autoantibodies, acantholysis, autoantibody, treatment, autoimmune disease, desmosome, ELISA, and immunofluorescence. The primary trending topic was rituximab drug, which is used in the treatment of Pemphigus. The other most studied trend topics were azathioprine drug used in treatment, intravenous immunoglobulin treatment, quality of life, mortality rates, Pemphigus herpetiformis, and wound healing.

A Global View of Pemphigus: Geographical Variations

Pemphigus, an autoimmune intraepidermal bullous disease group with roughly eight distinct forms, includes pemphigus vulgaris (PV) and pemphigus foliaceus (PF) as its predominant global forms. Despite the increased utilization of global health records and reporting systems, epidemiological data remain limited and poorly categorized. Therefore, this study aimed to conduct a review to track, identify, and characterize cases of PV and PF published and categorized worldwide. A research question was formulated; studies were selected based on the inclusion criteria; and data from these publications were systematically collected, summarized, and presented using narrative descriptions. The search strategy yielded 3,212 articles, of which 95 underwent critical analysis and data extraction. Studies from 52 countries contributed to the dataset, covering various pemphigus variants. Notably, only two countries, Iran (18.87%) and South Korea (11.43%), accounted for approximately a third of the reported PV cases, while Brazil contributed 40.25% of the foliaceus variants cases documented in the literature. These findings offer valuable insights into the global distribution of pemphigus and inform future research and healthcare efforts.

Clinical Features of Paediatric Inflammatory Epidermolysis Bullosa Acquisita: A Case Series Study

Epidermolysis bullosa acquisita (EBA) rarely develops in childhood. This study retrospectively recruited paediatric patients with EBA (age ≤ 16 years), diagnosed by clinical and histopathological features and results of immunofluorescence, immunoblotting and enzyme-linked immunosorbent assay (ELISA), and reviews their clinical manifestations, histopathology, immunological features, and responses to various treatments. All 7 included patients presented with inflammatory EBA. Among them, 3 had a bullous pemphigoid-like phenotype. Pathologically, in addition to dermal-epidermal blistering, in all patients, the distribution of neutrophils was superficial perivascular or interstitial, or in the dermal papilla. Mixed neutrophils and eosinophils were detected in 2 of the 3 patients with bullous pemphigoid-like phenotypes. In addition to treatment with glucocorticoids, dapsone was administered in 4 patients, while thalidomide and sulfasalazine were administered in 1 patient. All patients responded to the these therapies. Relapse was mainly due to reduction and cessation of glucocorticoids. In conclusion, EBA in childhood may be unique, and thus distinct from its adult counterpart. Specific treatment and follow-up protocols are required for therapy of this rare autoimmune skin disease in children.

Worldwide epidemiologic factors in pemphigus vulgaris and bullous pemphigoid

Autoimmune blistering diseases such as bullous pemphigoid (BP) and pemphigus vulgaris (PV) are complex, multifactorial, and polygenic diseases, whose exact pathogenesis is difficult to pinpoint. Research aimed at elucidating the associated epidemiologic risk factors of these two diseases has been hampered by their rare disease status. Further, a lack of centralization and standardization of available data makes the practical application of this information challenging. In order to collate and clarify the available literature we comprehensively reviewed 61 PV articles from 37 different countries and 35 BP articles from 16 different countries addressing a range of disease relevant clinical parameters including age of onset, sex, incidence, prevalence, and HLA allele association. The reported incidence of PV ranged from 0.098 to 5 patients per 100,000 people, while BP ranged from 0.21 to 7.63 patients per 100,000. Prevalence of PV ranged from 0.38 to 30 per 100,000 people and BP ranged from 1.46 to 47.99 per 100,000. The mean age of onset in patients ranged from 36.5 to 71 years for PV and 64 to 82.6 years for BP. Female-to-male ratios ranged from 0.46 to 4.4 in PV and 1.01 to 5.1 in BP. Our analysis provides support for the reported linkage disequilibrium of HLA DRB1*0402 (an allele previously shown to be associated with PV) and DQB1*0302 alleles in Europe, North America, and South America. Our data also highlight that HLA DQB1*0503 (also known to be associated with PV) appears in linkage disequilibrium with DRB1*1404 and DRB1*1401, mainly in Europe, the Middle East, and Asian countries. The HLA DRB1*0804 allele was only associated with PV in patients of Brazilian and Egyptian descent. Only two HLA alleles were reported as associated with BP more than twice in our review, DQB1*0301 and DQA1*0505. Collectively, our findings provide detailed insights into the variation of disease parameters relevant to PV and BP that can be expected to inform future work aimed at unraveling the complex pathogenesis of these conditions across the globe.

[Clinical aspects of ocular mucosal pemphigoid]

Mucosal pemphigoid is a rare chronic autoimmune disease that also affects the eyes in more than two thirds of all cases. Especially in the early phase of the ocular manifestation, the findings are subtle and the disease is often not recognized. The aim of this article is to provide the clinical aspects of ocular mucosal pemphigoid so that timely diagnostics can be initiated when this disease is suspected.

Blasenbildende Autoimmundermatosen – Klinik, Diagnostik und neue Therapieansätze

Diese Arbeit gibt eine Übersicht über die Gruppe blasenbildender Autoimmundermatosen und stellt deren wichtigste Vertreter, das bullöse Pemphigoid, den Pemphigus vulgaris sowie den Pemphigus foliaceus, vor. Die häufigste der insgesamt seltenen blasenbildenden Autoimmundermatosen ist das bullöse Pemphigoid (BP). Es betrifft vor allem Patienten jenseits des 60. Lebensjahrs. Charakterisiert ist es typischerweise durch das Auftreten praller Blasen, die mit einem heftigen Juckreiz einhergehen. Ein längeres, sogenanntes prämonitorisches Stadium ohne Blasenbildung ist nicht ungewöhnlich. Es gibt außerdem Varianten mit anderem Erscheinungsbild wie das lokalisierte BP. Der diagnostische Goldstandard ist die direkte Immunfluoreszenzmikroskopie einer periläsional entnommenen Hautbiopsie, welche lineare Ablagerungen von IgG und C3 an der Basalmembran zeigt. Vervollständigt wird die Diagnostik durch die indirekte Immunfluoreszenzmikroskopie sowie weiterführende ELISA-Untersuchungen, mittels derer zirkulierende Autoantikörper im Patientenserum nachgewiesen werden können. Das wichtigste Zielantigen ist BP180, ein hemidesmosomales, von Keratinozyten exprimiertes Protein. Ergänzend kann eine histopathologische Untersuchung erfolgen, die allerdings nur Hinweise zur Spaltebene und zum (meist Eosinophilen-dominierten) Infiltratmuster geben kann und alleine nicht zur Diagnosestellung ausreicht. Die Pathogenese des BP ist Gegenstand der wissenschaftlichen Diskussion. Medikamente wie Dipeptidylpeptidase-4-Inhibitoren können Auslöser sein; Assoziationen zu neurologischen Erkrankungen finden sich häufig. Entsprechend aktueller Leitlinien wird das BP mit topischen bzw. systemischen Glukokortikoiden ggf. in Kombination mit Doxyzyklin, Dapson oder einem Immunsuppressivum behandelt. Bei Therapieresistenz werden intravenöse Immunglobuline oder der anti-CD-20-Antikörper Rituximab eingesetzt. Aufgrund einer vergleichsweise hohen Mortalität bedingt durch Patientenalter und iatrogener Immunsuppression werden neue Therapieansätze gesucht. Fallserien, Kohortenanalysen und Phase 1-/2-Studien mit anti-IgE-Antikörpern und Inhibitoren der eosinophilen Granulozyten sowie des Komplementsystems zeigen teils vielversprechende Effekte. Die wichtigsten Vertreter der Pemphiguserkrankungen sind der Pemphigus vulgaris (PV), der Pemphigus foliaceus (PF) und der sehr seltene paraneoplastische Pemphigus (PNP). Klinisch präsentiert sich der PV mit meist enoralen Schleimhauterosionen und teilweise zusätzlichen Erosionen an der freien Haut. Der PF manifestiert sich nur an der freien Haut. Wie beim BP wird die Diagnose mittels direkter Immunfluoreszenzmikroskopie gestellt, welche beim PV und PF netzförmige Ablagerungen von IgG und C3 innerhalb der Epidermis zeigt. Die häufigsten Zielantigene sind die Desmogleine 1 und 3. Genetische Prädispositionen für den PV und PF sind bekannt und Grund für eine global unterschiedliche Häufigkeit. Der PNP ist immer mit einer malignen Erkrankung assoziiert und von einem progredienten Verlauf mit hoher Mortalität geprägt. Therapeutisch erfordern die Pemphiguserkankungen oft aggressivere Ansätze als das BP. Neben systemischen Glukokortikoiden und Immunsuppressiva wird für den PV und PF der anti-CD-20-Antikörper Rituximab empfohlen. Neue Therapieansätze sind die Hemmung der Bruton-Tyrosinkinase sowie des neonatalen Fc-Rezeptors (FcRN). In einer Phase 2-Studie zeigte Efgartigimod, ein Antagonist des FcRN, eine hohe Therapieeffektivität für Patienten mit PV und PF.

Unmet Medical Needs in Chronic, Non-communicable Inflammatory Skin Diseases

An estimated 20-25% of the population is affected by chronic, non-communicable inflammatory skin diseases. Chronic skin inflammation has many causes. Among the most frequent chronic inflammatory skin diseases are atopic dermatitis, psoriasis, urticaria, lichen planus, and hidradenitis suppurativa, driven by a complex interplay of genetics and environmental factors. Autoimmunity is another important cause of chronic skin inflammation. The autoimmune response may be mainly T cell driven, such as in alopecia areata or vitiligo, or B cell driven in chronic spontaneous urticaria, pemphigus and pemphigoid diseases. Rare causes of chronic skin inflammation are autoinflammatory diseases, or rheumatic diseases, such as cutaneous lupus erythematosus or dermatomyositis. Whilst we have seen a significant improvement in diagnosis and treatment, several challenges remain. Especially for rarer causes of chronic skin inflammation, early diagnosis is often missed because of low awareness and lack of diagnostics. Systemic immunosuppression is the treatment of choice for almost all of these diseases. Adverse events due to immunosuppression, insufficient therapeutic responses and relapses remain a challenge. For atopic dermatitis and psoriasis, a broad spectrum of innovative treatments has been developed. However, treatment responses cannot be predicted so far. Hence, development of (bio)markers allowing selection of specific medications for individual patients is needed. Given the encouraging developments during the past years, we envision that many of these challenges in the diagnosis and treatment of chronic inflammatory skin diseases will be thoroughly addressed in the future.

Global Incidence and Prevalence of Bullous Pemphigoid: a Systematic Review and meta-analysis

BACKGROUND

Integrated information on the global prevalence and incidence of bullous pemphigoid (BP) is lacking.

OBJECTIVE

To estimate the incidence and prevalence of BP in a systematic review and meta-analysis.

METHODS

Observational studies were included by using databases of Medline, EMBASE and Cochrane Library. Subgroup analysis was by continent, age, sex and country income level. Random-effects model was used. Between-study heterogeneity was assessed using the I² statistic.

RESULTS

The global incidence was 0.0419 per 1000 person-years (95% CI: 0.0414-0.0424). The incidence was 0.047 per 1000 person-years (95% CI: 0.0462-0.0477), 0.0419 per 1000 person-years (95% CI: 0.0411-0.0426), 0.0072 per 1000 person-years (95% CI: 0.0067-0.0078), 0.003 per 1000 person-years (95% CI: 0.0023-0.0039) in North America, Europe, Asia and Africa, respectively; 0.0202 per 1000 person-years (95% CI: 0.0196; 0.0208) and 0.0181 per 1000 person-years (95% CI: 0.0175; 0.0188) females and males; 0.001 per 1000 person-years (95% CI: 0.001-0.001), 0.002 per 1000 person-years (95% CI:0.001-0.002), 0.004 per 1000 person-years (95% CI: 0.004-0.004); 0.007 per 1000 person-years (95% CI: 0.007-0.008), 0.011 per 1000 person-years (95% CI: 0.011-0.012), 0.017 per 1000 person-years (95% CI: 0.015-0.018) for age < 50, 50-59, 60-69, 70-79, 80-89 and ≥90 years. 0.0038 per 1000 person-years (95% CI:0.0036-0.004112) (I2 = 99%, p<.05) and 0.0456 per 1000 person-years (95% CI:0.0450-0.0462) (I2 = 100%, p<.05). The pooled clinic-based prevalence was 0.79 % (95% CI: 0.75%-0.84%), and 1.13% (95% CI: 1.06%-1.21%), 0.21% (95% CI: 0.17%-0.26%), 0.13% (95% CI:0.1%-0.15%) for Asia, Africa and Europe.

CONCLUSIONS

This study identified the global incidence and prevalence of BP in terms of spatial and population distributions and among various income level. A relatively higher incidence was in Europe, females, older people and high-income level country. The prevalence was higher in Asia. These findings should be interpreted with caution due to high heterogeneity of included studies.

Mucous membrane pemphigoid

Mucous membrane pemphigoid (MMP) is a clinically and immunopathologically heterogenous disease with an incidence of about 2/million inhabitants/year in central Europe. Pemphigoid diseases are characterized by autoantibodies against structural proteins of the epidermis and/or surface-close epithelia. MMP has been defined as pemphigoid disease with predominant mucosal lesions. Most frequently, the oral cavity and the conjunctivae are affected. Lesions outside the mouth tend to heal with scarring leading to visual impairment and finally blindness, as well as, more rarely, impairment of breathing and food intake. Autoantibodies target BP180 (collagen type XVII), laminin 332, BP230 (nearly always in conjunction with other antigens), and type VII collagen in about 75%, 10-20%, 10-30%, and <5% of MMP patients, respectively. While the main autoantibody isotype is IgG, additional, and less frequently, exclusive IgA autoantibodies can be detected in the majority of patients. Assaying for anti-laminin 332 reactivity is pivotal, since in about a quarter of patients with anti-laminin 332 MMP, a malignancy, mainly solid cancers, is associated. The pathophysiology of MMP is yet incompletely understood. A recent mouse model of anti-laminin 332 MMP replicating characteristic clinical and immunopathological findings of the human disease may be helpful to close this knowledge gap. Diagnosis is established by the clinical picture with predominant mucosal lesions and visualization of tissue-bound anti-basement membrane zone antibodies by direct immunofluorescence microscopy. In recent S3 guidelines initiated by the European Academy of Dermatology and Venereology, the clinical spectrum and diagnostic strategies are detailed. In addition, treatment regimens for different clinical situations including patients with exclusive oral or ocular involvement are outlined. Future studies are needed to better understand the clinal complexity and associations as well as to establish widely available diagnostic assays and evidence-based therapeutic strategies.

An Updated Review of Pemphigus Diseases

Clinicians may encounter a variety of skin conditions that present with vesiculobullous lesions in their everyday practice. Pemphigus vulgaris, pemphigus foliaceus, IgA pemphigus, and paraneoplastic pemphigus represent the spectrum of autoimmune bullous dermatoses of the pemphigus family. The pemphigus family of diseases is characterized by significant morbidity and mortality. Considering the risks associated with a delayed diagnosis or misdiagnosis and the potential for overlap in clinical features and treatment, evaluation for suspected pemphigus disease often requires thorough clinical assessment and laboratory testing. Diagnosis is focused on individual biopsies for histopathology and direct immunofluorescence. Additional laboratory methods used for diagnosis include indirect immunofluorescence and enzyme-linked immunosorbent assay. Recent advancements, including anti-CD20 therapy, have improved the efficacy and reduced the morbidity of pemphigus treatment. This contribution presents updates on the pathophysiology, clinical features, diagnostic work-up, and medical management of pemphigus. Improved strategies for diagnosis and clinical assessment are reviewed, and newer treatment options are discussed.

Bullous Autoimmune Dermatoses

BACKGROUND

Bullous autoimmune dermatoses are a clinically and immunopatho - logically heterogeneous group of diseases, characterized clinically by blisters or erosions of the skin and/or mucous membranes. In Germany, their prevalence is approximately 40 000 cases nationwide, and their incidence approximately 20 new cases per million people per year.

METHODS

This review is based on publications that were retrieved by a selective search of the literature focusing on the current German and European guidelines.

RESULTS

Recent years have seen the publication of guidelines, controlled prospective clinical trials, and multicenter diagnostic studies improving both diagnosis and therapy. Specific monovalent and multivariate serological test systems and pattern analysis of tissue-bound autoantibodies allow identification of the target antigens in 80-90% of patients. This enables the precise classification of disease entities, with implications for treatment selection and disease outcome. In 2019, the anti-CD20 antibody rituximab was approved by the European Medicines Agency for the treatment of moderate and severe pemphigus vulgaris, with an ensuing marked improvement in the care of the affected patients. To treat mild and moderate bullous pemphigoid, topical clobetasol proprionate is recommended, in severe disease, combined with systemic treatment, i.e. usually (a) prednisolone p.o. at an initial dose of 0.5mg/kg/d , (b) an immunomodulant, e.g. dapsone or doxycycline, or (c) prednisolone plus an immunomodulant.

CONCLUSION

The early recognition and precise diagnostic evaluation of bullous autoimmune dermatoses now enables improved, often interdisciplinary treatment, in accordance with the available guidelines. Current research projects are focused on new treatment approaches, an improved understanding of the underlying pathophysiology, and further refinements of diagnostic techniques.

A rare case of childhood mucous membrane pemphigoid involving the oral and genital mucosa

Mucous membrane pemphigoid (MMP) is a rare chronic immunobullous disease that involves the mucous membranes and may result in significant scarring and complications if diagnosis is delayed. MMP typically occurs in elderly patients, with very few cases reported in children. Here, we present a 12-year-old female patient with childhood-onset oral and genital MMP, clinically suspected to be lichen sclerosus, but eventually diagnosed as MMP after multiple supportive biopsies and confirmatory direct immunofluorescence. Although treatment was challenging, the combined use of systemic corticosteroids, dapsone, and mycophenolate mofetil was ultimately successful in achieving disease control.

Epidemiology of Pemphigus

Pemphigus is an epidemiologically heterogeneous group of autoimmune bullous diseases comprising pemphigus vulgaris (PV), pemphigus foliaceus, paraneoplastic pemphigus, IgA pemphigus, and pemphigus herpetiformis. Recently, our knowledge about the frequency of pemphigus, which is highly variable between different populations, has considerably expanded, and the first non-HLA genes associated with PV have been identified. In addition, a variety of comorbidities, including other autoimmune diseases, hematological malignancies, and psoriasis, have been described in this variant. Here, initial data about the impact of COVID-19 on this fragile patient population are discussed and perspectives for future epidemiological studies are outlined.

Spectrum of autoimmune bullous diseases among children in Kuwait

BACKGROUND

Autoimmune bullous diseases (AIBD) are rare among children. The data describing the overall spectrum and prognosis of pediatric AIBD (pAIBD) are scarce, and there are no established treatment guidelines.

OBJECTIVES

The present study examined the spectrum, clinical characteristics, and long-term prognosis of pAIBD in a tertiary care pediatric dermatology unit.

METHODS

Retrospective records of all pAIBD cases (<18 years) registered over a span of 28 years were analyzed.

RESULTS

Records of 23 cases of pAIBD, including 16 boys and 7 girls, were reviewed. They constituted 8.5% of total AIBD patients from all age groups. Ninety-one percent of patients were of Arab ethnicity. Linear IgA bullous dermatosis was the most prevalent AIBD followed by bullous pemphigoid, bullous lupus erythematosus, and pemphigus variants (pyostomatitis-pyodermatitis vegetans and neonatal pemphigus). The mean age of onset and diagnosis was 6.4 and 7.7 years, respectively. Systemic treatments, including systemic corticosteroids and dapsone, were required in most cases. Intravenous immunoglobulin G (IVIG) was also utilized as second-line therapy. The mean follow-up period was 76 months with 90% of the patients in complete remission.

CONCLUSIONS

AIBD pose a great challenge among children both in diagnosis and treatment. This study highlights the ethnic variability and underscores the need for additional similar, international studies to achieve a better understanding of the burden related to pAIBD and help establish treatment guidelines.