Spectrum of subepidermal immunobullous disorders seen at the National Skin Centre, Singapore: a 2-year review

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.

Lichen planus pemphigoides with predominant mucous membrane involvement: a series of 12 patients and a literature review

Background

Lichen planus pemphigoides (LPP), an association between lichen planus and bullous pemphigoid lesions, is a rare subepithelial autoimmune bullous disease. Mucous membrane involvement has been reported previously; however, it has never been specifically studied.

Methods

We report on 12 cases of LPP with predominant or exclusive mucous membrane involvement. The diagnosis of LPP was based on the presence of lichenoid infiltrates in histology and immune deposits in the basement membrane zone in direct immunofluorescence and/or immunoelectron microscopy. Our systematic review of the literature, performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, highlights the clinical and immunological characteristics of LPP, with or without mucous membrane involvement.

Results

Corticosteroids are the most frequently used treatment, with better outcomes in LPP with skin involvement alone than in that with mucous membrane involvement. Our results suggest that immunomodulators represent an alternative first-line treatment for patients with predominant mucous membrane involvement.

Role of Human Leukocyte Antigen Class II in Antibody-Mediated Skin Disorders

HLA class II molecules are key factors determining susceptibility to autoimmune disorders, and their role in immune-mediated skin conditions such as psoriasis has been extensively investigated. However, there is currently little understanding of their role in antibody-mediated skin diseases such as autoimmune blistering disorders. We researched the available literature using PubMed to narratively review the current knowledge on HLA associations in antibody-mediated blistering skin pathologies. Our results summarized the risk alleles that are identified in the literature, together with certain known protective alleles: in the pemphigus group, alleles HLA-DQB1*0503 and HLA-DRB1*0402 are most commonly associated with disease; in the pemphigoid group, the most studied allele is HLA-DQB1*0301; in epidermolysis bullosa acquisita, few genetic studies are available; in dermatitis herpetiformis, the association with haplotypes HLA-DQ2 and HLA-DQ8 is strongly established; finally, in linear IgA bullous disease, specific HLA alleles may be responsible for pediatric presentations. Our current pathogenic understanding of this group of disorders assigns a key role to predisposing HLA class II alleles that are able to bind disease autoantigens and therefore stimulate antigen-specific autoreactive T cells. The latter engage B lymphocytes that will produce pathogenic autoantibodies. The distribution of HLA alleles and their disease associations are variable across demographics, and an in-depth pathogenetic understanding is needed to support associations between HLA alleles and disease phenotypes. Additionally, in a personalized medicine approach, the identification of HLA alleles associated with the risk of disease may become clinically relevant in identifying susceptible subjects that should avoid exposure to known triggers, such as medication, when possible.

[Immunopathogenesis of mucous membrane pemphigoid]

A detailed understanding of the immunopathogenesis of mucous membrane pemphigoid (MMP) is of particular importance in view of the mostly difficult diagnostics and treatment of this blistering autoimmune dermatosis. A still unknown disturbance of the body's own immune tolerance leads to the formation of autoreactive cells. As the disease progresses these produce autoantibodies which are directed against structural proteins in the basement membrane zone (BMZ). After they bind to the target antigen, complement factors are deposited along the BMZ and inflammatory cells invade the underlying tissue and produce the characteristic subepithelial blistering. This inflammatory response is associated with fibrosis and scarring in many affected tissues. Most phases of MMP pathogenesis are poorly understood; however, the last few years have shed more light on this processes. These advances are mostly the result of animal and cell culture models. Typical clinical and immunopathological characteristics of MMP, such as oral, conjunctival and skin lesions, are reflected, for example, in an antibody transfer-induced mouse model for anti-laminin 332 MMP in adult mice. Dapsone, as first-line treatment for MMP patients, significantly reduced the severity of these symptoms, and fibrosis in the skin and mucous membranes was also found histologically, which makes the model well-suited for testing new therapeutic approaches for MMP patients and might be of help for further elucidation of the immunopathogenesis of MMP.

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.

Concordance of Clinical, Histologic and Direct Immunofluorescence Findings in Patients with Autoimmune Bullous Dermatoses in Vietnam

Introduction: Autoimmune bullous dermatoses (ABD) represent a heterogeneous group of blistering disorders that may be debilitating with high morbidity. Clinical, histological, and direct immunofluorescence (DIF) studies are essential in establishing an accurate diagnosis of ABD, which is essential for its clinical management. Our study objective was to perform a systematic evaluation of ABD cases in a patient population at an academic medical center in Ho Chi Minh City, Vietnam, and determine the degree of concordance of clinical, histological, and DIF findings in ABD. Methodology: A systematic retrospective cross-sectional study was performed on 92 patients diagnosed with ABD by clinical, histological, and DIF studies at the University of Medicine and Pharmacy in Ho Chi Minh City, Vietnam, between September 2019 and September 2021. The clinical histories, H and E stained tissue sections, and DIF stains were evaluated by pathologists at the University of Medicine and Pharmacy. Results: ABD was evaluated as a whole and subdivided into an intraepidermal blister subgroup and a subepidermal blister subgroup. The analysis of paired diagnostic methods (clinical, histological, and DIF) for concordance with the final diagnosis was performed and showed that there were no statistically significant differences between the paired methods (McNemar’s test, p > 0.05). There was moderate concordance between the clinical, histological, and DIF diagnoses among all ABD cases (Brennan-Prediger coefficient Kappa test, κBP = 0.522, CI = 0.95). In the intraepidermal blister subgroup, the diagnostic accuracies of the histology and DIF stains were comparable to each other, and both were more accurate than a clinical diagnosis alone. In the subepidermal blister subgroup, there was no statistically significant difference in each pair of the three diagnostic methods (clinical, histological, and DIF) (McNemar’s test, p > 0.05). The concordance between the clinical, histological, and DIF diagnoses was high for the intraepidermal blister subgroup (Kappa test, κBP = 0.758, CI = 0.95). However, the concordance between the clinical, histological, and DIF diagnoses was slight for the subepidermal blister subgroup (Kappa test, κBP = 0.171, CI = 0.95). Conclusion: Histological evaluation is highly accurate in the diagnosis of the intraepidermal blister subgroup, but it is not as accurate in the diagnosis of the subepidermal blister subgroup in the Vietnamese patient cohort in which clinical, histological, and DIF studies were performed. DIF stains are a crucial diagnostic tool for ABD in this patient population.

Type XVII collagen: Relevance of distinct epitopes, complement-independent effects, and association with neurological disorders in pemphigoid disorders

Pemphigoid diseases (PD) are autoimmune skin blistering diseases characterized by autoantibodies directed against proteins of the cutaneous basement membrane zone (BMZ). One of the major antigens is type XVII collagen (BP180), a transmembrane glycoprotein, which is targeted in four PDs: bullous pemphigoid, mucous membrane pemphigoid, linear IgA dermatosis, and pemphigoid gestationis. To date, different epitopes on BP180 have been described to be recognized by PD disease patients’ autoantibodies. Different BP180 epitopes were associated with distinct clinical phenotypes while the underlying mechanisms are not yet fully understood. So far, the main effects of anti-BP180 reactivity are mediated by Fcγ-receptors on immune cells. More precisely, the autoantibody–antigen interaction leads to activation of complement at the BMZ and infiltration of immune cells into the upper dermis and, by the release of specific enzymes and reactive oxygen species, to the degradation of BP180 and other BMZ components, finally manifesting as blisters and erosions. On the other hand, inflammatory responses independent of Fcγ-receptors have also been reported, including the release of proinflammatory cytokines and internalization and depletion of BP180. Autoantibodies against BP180 can also be found in patients with neurological diseases. The assumption that the clinical expression of PD depends on epitope specificity in addition to target antigens, autoantibody isotypes, and antibody glycosylation is supported by the observation that epitopes of PD patients differ from those of PD patients. The aim of the present review is to describe the fine specificities of anti-BP180 autoantibodies in different PDs and highlight the associated clinical differences. Furthermore, the direct effects after binding of the autoantibodies to their target are summarized.

Bullous pemphigoid: Its incidence, mortality and clinical outcome in New Zealand

BACKGROUND/OBJECTIVES

Bullous pemphigoid (BP) is an uncommon autoimmune bullous disorder, with significant morbidity and mortality. Mortality may be as high as 23.5% in the first year after diagnosis. Clear epidemiologic data across Australasia are lacking.

METHODS

A retrospective, multi-centred cohort study was designed to determine the incidence and mortality of bullous pemphigoid in New Zealand. Data from all histopathologically diagnosed patients with bullous pemphigoid between 2009 and 2015 from the Auckland region were obtained. Demographics, clinical characteristics and outcome 3 years from diagnosis (until 31 December 2018) were collected. Demographic data were compared against a denominator year-matched New Zealand Census population.

RESULTS

One hundred sixty-one patients had confirmed bullous pemphigoid, with an incidence rate of 3.03/100 000 person-years [95% CI 2.58-3.54]; 70% were of European ethnicity; 12.4% were Pacific peoples; 11.2% were Asian; and 6.8% were Māori. 45.3% had associated cognitive impairment and/or stroke. In the 3-year follow-up, 25% had treatment complications mostly from prednisone therapy. The mortality rate was 40%, highest in the first year of diagnosis, with age at diagnosis a predictor.

CONCLUSION

The incidence and mortality rates are comparable to the UK/Northern Europe. Knowledge of the epidemiology of bullous pemphigoid in New Zealand and within an international settling informs the provision of future care and treatments.

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.

A multicentre prospective analysis of the incidence of pemphigoid diseases in Turkey

BACKGROUND

The differentiation between the pemphigoid diseases is essential for treatment and prognosis. In Turkey, data on the incidence of these diseases are insufficient. Our aim in this study is to determine the incidence, demographics and clinical characteristics associated with diseases of the pemphigoid group.

METHODS

We prospectively analysed 295 patients with pemphigoid who visited dermatology clinics of tertiary referral hospitals in 12 different regions of Turkey within a year. The diagnosis was based on clinical, histopathological, direct immunofluorescence (DIF) and serological (multivariant enzyme-linked immunosorbent assay [ELISA], indirect immunofluorescence and mosaic-based BIOCHIP) examinations. Clinical and demographic findings, aetiological factors and concomitant diseases observed in the patients were recorded.

RESULTS

A total of 295 (female/male ratio: 1.7/1) patients with pemphigoid were diagnosed in 1-year period. The overall incidence rate of pemphigoid diseases was found to be 3.55 cases per million-years. The ratio of pemphigoid group diseases to pemphigus group diseases was 1.6. The most common pemphigoid type was bullous pemphigoid (BP, 93.2%). The others were epidermolysis bullosa acquisita (3.1%), pemphigoid gestationis (2.4%), linear IgA disease (1%) and mucous membrane pemphigoid (0.3%). The most common (26.8%) possible trigger of the bullous pemphigoid was gliptin derivative drugs. The most common concomitant diseases with pemphigoid were cardiovascular (27.8%) and neurological diseases (23.7%).

CONCLUSIONS

This study showed that the increased frequency of bullous pemphigoid reversed the pemphigoid/pemphigus ratio in Turkey. Further studies are warranted regarding the reasons for this increase.

The global incidence of bullous pemphigoid: a systematic review and meta-analysis

BACKGROUND

Bullous pemphigoid (BP) is an autoimmune blistering disorder that mainly affects older people. Although the disease is associated with considerable morbidity and mortality, the burden of disease worldwide is unclear.

OBJECTIVES

The study aim is to pool the global incidence of BP and determine whether this varies according to geographic area, age group, setting and study quality.

METHODS

Ovid MEDLINE, Ovid Embase and grey literature were systematically searched on 7 April 2020. Two reviewers independently screened, extracted data and appraised each study's quality using the Joanna Briggs Institute critical appraisal tool. Two domains, indicative of selection and survey bias, were used to identify high-quality studies. The cumulative incidence was standardized to 1 year and pooled in a random-effects meta-analysis. Subgroup and sensitivity analyses were conducted.

RESULTS

Twenty-seven studies were identified, of which 23 provided cumulative incidence and four provided incidence rates. The cumulative incidence of BP was 8·2 [95% confidence interval (CI) 4·8-13.7] per million people whereas the incidence rate was 34·2 (95% CI 19·2-60·7) per million person-years. Of the continents that contributed more than one study, the cumulative incidence was 10·3 (95% CI 5·8-18·2) and 5·6 (95% CI 3·5-9·0) per million people in Europe and Asia, respectively. The incidence was highest in studies including adults only (n = 2), in population-based studies (n = 9) and in more recent years. The cumulative incidence was higher (13·3 per million people, 95% CI 6·0-29·5) when restricting the analysis to higher-quality studies (n = 11). High heterogeneity (I² > 82%) was observed across all pooled estimates.

CONCLUSIONS

The incidence of BP varies globally, is generally low but appears to be increasing over time. The burden of disease is likely to be underestimated.

The epidemiology of autoimmune bullous diseases in Sudan between 2000 and 2016

Objectives

Autoimmune bullous diseases vary in their clinico-epidemiological features and burden across populations. Data about these diseases was lacking in Sudan. We aimed to describe the epidemiological profile and to estimate the burden of autoimmune bullous diseases in Sudan.

Methods

This was a retrospective cross-sectional study conducted at Khartoum Dermatological and Venereal Diseases Teaching Hospital. We used routinely collected health care data, and included all patients with an autoimmune bullous disease who presented to the hospital between 2001 and 2016.

Results

Out of the 4736 patients who were admitted to the hospital during the study period, 923 (19.5%) had an autoimmune bullous disease. The average rate of patients at the hospital was 57.7 per year representing 1.3 per 100,000 population per year. After exclusion of patients where the final diagnosis was missing, 585 were included in the further analysis. Pemphigus vulgaris was the most common disease (50.9%), followed by bullous pemphigoid (28.2%), linear IgA disease/chronic bullous disease of childhood (8.4%), and pemphigus foliaceous (8.2%). Pemphigoid gestationis and IgA pemphigus constituted 1.4% and 1.2% of the cohort, respectively. Paraneoplastic pemphigus, mucous membrane pemphigoid, lichen planus pemphigoidis, bullous systemic lupus erythematosus, and dermatitis herpetiformis were rare. None of the patients had epidermolysis bullosa acquisita.

Conclusions

The clinico-epidemiological characteristics vary among the types of autoimmune bullous diseases. Females were more predominant in most of them. Sudanese patients tended in general to present at a younger age than other populations. The pool of Sudanese patients with autoimmune bullous diseases is large which requires investigation for the local risk factors and presents a field for future trials.

Analysis of the Clinical Characteristics of Dipeptidyl Peptidase-4 Inhibitor-Induced Bullous Pemphigoid

OBJECTIVE

To analyze and discuss the clinical characteristics of dipeptidyl peptidase-4 inhibitor (DPP4i)-induced bullous pemphigoid (BP).

DATA SOURCES

We collected case reports of DPP4i-induced BP by searching databases from 2006 to mid-May 2021, as a retrospective analysis.

STUDY SELECTION AND DATA EXTRACTION

Relevant case reports and case analyses of DPP4i-induced BP were included.

DATA SYNTHESIS

The median time of symptom onset was 9 months (range 0.5-59 months). BP most often occurred in patients receiving vildagliptin (52.63%) followed by linagliptin (27.19%) and sitagliptin (17.54%). Tense bullae and blisters (85.51%) and erythema (82.61%) on the extremities and trunk were the most common presenting symptoms. In total, 64.06% of BP patients were anti-BP180 autoantibody positive, 58.97% were BP180NC16a autoantibody positive, and 31.25% were anti-BP230 autoantibody positive. Skin biopsy revealed subepidermal bulla eosinophil infiltration in 93.85% of BP patients, lymphocyte infiltration in 56.93%, and neutrophil infiltration in 44.62%. Direct immunofluorescence was positive in 98.94% of BP patients with linear deposition of IgG (97.80%) and/or complement C3 (98.94%) along the basement membrane zone. Indirect immunofluorescence was positive in 87.88% of BP patients. Complete remission of BP was achieved in 83.64% of patients on DPP4i withdrawal and after 4 months (range 0.13-72 months) of follow-up.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review analyzes and discusses the clinical characteristics of DPP4i-induced BP and provides a reference for the safe and reasonable clinical application of DPP4i.

CONCLUSIONS

DPP4i drugs are related to the occurrence of BP in diabetic patients, especially elderly men taking vildagliptin.

Subepithelial autoimmune blistering dermatoses: Clinical features and diagnosis

Subepithelial autoimmune blistering dermatoses are a group of rare skin disorders that are characterized by the disruption of the dermal-epidermal junction through the action of autoantibodies. The third article in this continuing medical education series explores the background, epidemiology, clinical features, and diagnostic criteria of each of the major subepithelial autoimmune blistering dermatoses, including bullous pemphigoid, pemphigoid gestationis, lichen planus pemphigoides, mucous membrane pemphigoid, linear IgA bullous dermatosis, and dermatitis herpetiformis.

A survey of bullous diseases in a Turkish university hospital: clinicoepidemiological characteristics and follow-up

Background/aim

Autoimmune bullous diseases, if left untreated, are life-threatening conditions affecting primarily skin and mucous membranes. These blistering disorders are characterized by epidermal or subepidermal detachment. Autoimmunity plays a key role in pathogenesis; therefore, immunosuppressive agents are the treatment of choice. The aim of this study is to document relative frequencies of different autoimmune bullous diseases, patient characteristics, treatment options, and side effects in patients presenting to our bullous skin disease center at İstanbul University, Cerrahpaşa, Cerrahpaşa Medical Faculty.

Materials and methods

Medical files were examined retrospectively for all patients with autoimmune bullous diseases who were followed up between 2003 and 2019 at the Bullous Skin Disease Center at İstanbul University, Cerrahpaşa.

Results

A total of 346 patient files were examined. Pemphigus vulgaris was the most frequent autoimmune bullous disease, followed by bullous pemphigoid and pemphigus foliaceus, according to our study. There is a general female predominancy for all autoimmune bullous diseases. The most commonly preferred treatment options were high-dose daily corticosteroids.

Conclusion

This retrospective study summarizes the patient characteristics, comorbidities, treatment choices, and side effects during 16 years of clinical practice.

Incidence of pemphigoid diseases in Northern Germany in 2016 - first data from the Schleswig-Holstein Registry of Autoimmune Bullous Diseases

BACKGROUND

Autoimmune bullous diseases (AIBD) are rare disorders characterized by autoantibody formation against components of adhesion molecules; in pemphigoid diseases (PD), these are proteins of hemidesmosomes and basement membrane, important for cell-matrix adhesion in skin and/or mucous membranes. Incidences of these diseases vary considerably between different populations.

OBJECTIVES

To establish a registry prospectively recruiting all AIBD patients in a geographically well-defined region in Northern Germany (Schleswig-Holstein).

METHODS

Only patients with verified disease (by clinical presentation, histology, direct and/or indirect immunofluorescence and /or ELISA) living in Schleswig-Holstein were included. Incidences of PD were estimated based on the total number of inhabitants in Schleswig-Holstein, stratified by birth year and sex.

RESULTS

Of 67 patients with PD [35 male, 32 female, mean age 75 (standard deviation 14.3 years)], 83% were patients with bullous pemphigoid [n = 56, 28 male, 28 female, mean age 78 (SD 9.9)]. The resulting crude incidences were 23.4 patients/million/year for all pemphigoid patients, 19.6 patients/million/year for bullous pemphigoid (age-standardized 16.9 patients/million/year) with a strong increase in bullous pemphigoid patients in the age group of 85-90 years with 262 patients/million/year. Incidences for bullous pemphigoid were higher in urban compared to rural areas. Other PD (mucous membrane pemphigoid, linear IgA disease, anti-p200 pemphigoid) were less frequent with crude incidences of 2.1, 1.0 and 0.7 patients/million/year, respectively.

CONCLUSIONS

This study prospectively analyses the incidence of PD in a carefully defined geographical area. The highest incidence among PD patients was found for bullous pemphigoid. The incidence of bullous pemphigoid is considerably increased compared to previous reports and reveals regional differences. Further studies are needed in order to clarify these findings.

Bullous pemphigoid is a common associated disorder with acquired haemophilia A

Although the estimated incidence of acquired haemophilia A (AHA) in Singapore is similar to those reported in the literature, we have observed differences in the frequency of their associated diseases, particularly bullous pemphigoid (BP). We investigated the actual incidence of BP among our AHA cohort, their clinical characteristics and treatment outcomes. 6 out of 37 (16%) patients with AHA had BP, making it the most common underlying disorder in our cohort. The median age at diagnosis of AHA was 76 years old with a female preponderance. Most patients had their AHA diagnosed after BP with the median time between BP to AHA diagnosis being 107.5 days. Initial haemostasis was achieved, and factor VIII inhibitor was eliminated in all patients with a median time of disappearance being 52 days. Two patients had recurrence of their factor VIII inhibitor during the tapering of their immunosuppression. There was no relationship between the relapse of BP and AHA. This study suggests that BP is a common association with AHA. These patients respond well to bypassing agent and immunosuppression. However, they have a higher recurrence of factor VIII inhibitor and should be monitored closely for relapse during the tapering period of their immunosuppression.

A Review Comparing International Guidelines for the Management of Bullous Pemphigoid, Pemphigoid Gestationis, Mucous Membrane Pemphigoid, and Epidermolysis Bullosa Acquisita

Autoimmune blistering disease management can be challenging as treatment modalities vary greatly and no single standard of care exists. We consolidated the recommendations of international management guidelines in order to provide optimal management suggestions to physicians. A comprehensive literature search in PubMed/MEDLINE for published blistering disease management guidelines and consensus statements was conducted in November 2019. Search terms included "guideline or guidelines" or "consensus" and "pemphigoid" or "autoimmune blistering disease" or "epidermolysis bullosa acquisita". We included guidelines from established dermatologic societies and expert consensus groups. We excluded literature reviews, guidelines established by an association without dermatologists, or those specific to a single treatment. Guidelines in all languages were considered. Eleven guidelines from dermatologic associations and consensus groups meeting our inclusion criteria were selected. Several differences between recommendations, most notably when to introduce adjuvants for refractory disease, were found in bullous pemphigoid. In mucous membrane pemphigoid, treatment was directed to the sites involved and managed with systemic corticosteroids and immunosuppressants/biologics. There was no universal consensus on the first-line treatment for epidermolysis bullosa acquisita, but a combination of immunosuppressive, anti-inflammatory, and anti-neutrophil therapy was utilized. Comparison of the management guidelines revealed underrepresentation of guidelines from developing nations and key differences between the management styles among dermatologists from Europe and Asia. We attribute these discrepancies to the time elapsed between guidelines, regional differences, and demands of the local healthcare systems.

Incidence, prevalence and mortality of bullous pemphigoid in England 1998-2017: a population-based cohort study

BACKGROUND

A rising incidence and high mortality were found for bullous pemphigoid (BP) over a decade ago in the UK. Updated estimates of its epidemiology are required to understand the healthcare needs of an ageing population.

OBJECTIVES

To determine the incidence, prevalence and mortality rates of BP in England from 1998 to 2017.

METHODS

We conducted a cohort study of longitudinal electronic health records using the Clinical Practice Research Datalink and linked Hospital Episode Statistics. Incidence was calculated per 100 000 person-years and annual point prevalence per 100 000 people. Multivariate analysis was used to determine incidence rate ratios by sociodemographic factors. Mortality was examined in an age-, sex- and practice-matched cohort, using linked Office of National Statistics death records. Hazard ratios (HRs) were stratified by matched set.

RESULTS

The incidence was 7·63 [95% confidence interval (CI) 7·35-7·93] per 100 000 person-years and rose with increasing age, particularly for elderly men. The annual increase in incidence was 0·9% (95% CI 0·2-1·7). The prevalence almost doubled over the observation period, reaching 47·99 (95% CI 43·09-53·46) per 100 000 people and 141·24 (95% CI 125·55-158·87) per 100 000 people over the age of 60 years. The risk of all-cause mortality was highest in the 2 years after diagnosis (HR 2·96; 95% CI 2·68-3·26) and remained raised thereafter (HR 1·54; 95% CI 1·36-1·74).

CONCLUSIONS

We report a modest increase in the incidence rate of BP, but show that the burden of disease in the elderly population is considerable. Mortality is high, particularly in the first 2 years after diagnosis.

Lichen Planus Pemphigoides: From Lichenoid Inflammation to Autoantibody-Mediated Blistering

Lichen planus pemphigoides (LPP) is a very rare autoimmune sub-epidermal blistering disease associated with lichenoid skin changes. Initially thought to be a mere variant of more common inflammatory dermatoses, particularly Bullous Pemphigoid (BP) or Lichen Planus (LP), a growing body of evidence suggests that it is a disease entity in its own right. In common with a range of autoimmune blistering diseases, including BP, pemphigoid gestationis (PG), mucous membrane pemphigoid (MMP) and linear IgA dermatosis (LAD), a key feature of the disease is the development of autoantibodies against type XVII collagen (COL17). However, accurately establishing the diagnosis is dependent on a careful correlation between the clinical, histological and immunological features of the disease. Therefore, we present an up to date summary of the epidemiology and etiopathogenesis of LPP, before illustrating the predisposing and precipitating factors implicated in the development of the disease. In addition to a selective literature search, we compare reports of potential drug-induced cases of LPP with pharmacovigilance data available via OpenVigil. We subsequently outline the cardinal clinical features, important differential diagnoses and current treatment options. We conclude by demonstrating that an improved understanding of LPP may not only lead to the development of novel treatment strategies for the disease itself, but may also shed new light on the pathophysiology of more common and treatment-refractory autoimmune blistering diseases.

Bullous pemphigoid

Bullous pemphigoid is the most frequent autoimmune bullous disease and mainly affects elderly individuals. Increase in incidence rates in the past decades has been attributed to population aging, drug-induced cases and improvement in the diagnosis of the nonbullous presentations of the disease. A dysregulated T cell immune response and synthesis of IgG and IgE autoantibodies against hemidesmosomal proteins (BP180 and BP230) lead to neutrophil chemotaxis and degradation of the basement membrane zone. Bullous pemphigoid classically manifests with tense blisters over urticarial plaques on the trunk and extremities accompanied by intense pruritus. Mucosal involvement is rarely reported. Diagnosis relies on (1) the histopathological evaluation demonstrating eosinophilic spongiosis or a subepidermal detachment with eosinophils; (2) the detection of IgG and/or C3 deposition at the basement membrane zone using direct or indirect immunofluorescence assays; and (3) quantification of circulating autoantibodies against BP180 and/or BP230 using ELISA. Bullous pemphigoid is often associated with multiple comorbidities in elderly individuals, especially neurological disorders and increased thrombotic risk, reaching a 1-year mortality rate of 23%. Treatment has to be tailored according to the patient's clinical conditions and disease severity. High potency topical steroids and systemic steroids are the current mainstay of therapy. Recent randomized controlled studies have demonstrated the benefit and safety of adjuvant treatment with doxycycline, dapsone and immunosuppressants aiming a reduction in the cumulative steroid dose and mortality.

Subepidermal autoimmune bullous diseases: overview, epidemiology, and associations

Subepidermal autoimmune bullous diseases of the skin and mucosae comprise a large group of chronic diseases, including bullous pemphigoid, pemphigoid gestationis, mucous membrane pemphigoid, linear IgA bullous dermatosis, epidermolysis bullosa acquisita, and anti-p200 pemphigoid. These diseases are characterized by an antibody response toward structural components of the basement membrane zone, resulting in subepidermal blistering. The epidemiological features of these diseases vary substantially in different regions of the world. Observational studies investigating comorbidities and associations among patients with these diseases are inconsistent and sometimes inconclusive. This review provides a brief overview regarding each one of the subepidermal autoimmune bullous diseases. In addition, it summarizes the most recent understanding of the epidemiological features and associations of this group of organ-specific autoimmune diseases.

Epidermolysis Bullosa Acquisita: The 2019 Update

Epidermolysis bullosa acquisita (EBA) is an orphan autoimmune disease. Patients with EBA suffer from chronic inflammation as well as blistering and scarring of the skin and mucous membranes. Current treatment options rely on non-specific immunosuppression, which in many cases, does not lead to a remission of treatment. Hence, novel treatment options are urgently needed for the care of EBA patients. During the past decade, decisive clinical observations, and frequent use of pre-clinical model systems have tremendously increased our understanding of EBA pathogenesis. Herein, we review all of the aspects of EBA, starting with a detailed description of epidemiology, clinical presentation, diagnosis, and current treatment options. Of note, pattern analysis via direct immunofluorescence microscopy of a perilesional skin lesion and novel serological test systems have significantly facilitated diagnosis of the disease. Next, a state-of the art review of the current understanding of EBA pathogenesis, emerging treatments and future perspectives is provided. Based on pre-clinical model systems, cytokines and kinases are among the most promising therapeutic targets, whereas high doses of IgG (IVIG) and the anti-CD20 antibody rituximab are among the most promising "established" EBA therapeutics. We also aim to raise awareness of EBA, as well as initiate basic and clinical research in this field, to further improve the already improved but still unsatisfactory conditions for those diagnosed with this condition.

Incidence of autoimmune bullous diseases in Serbia: a 20-year retrospective study

BACKGROUND AND OBJECTIVES

While most previous surveys on the clinico-epidemiological features of autoimmune bullous diseases (AIBDs) have predominantly focused on a single disease entity or just one disease group, there have been only few studies examining the incidence of various AIBDs. In the present study, we set out to determine the spectrum of AIBDs, to estimate the incidence of the most common AIBDs, and to examine their temporal trends in Central Serbia over a period of 20 years.

METHODS

We retrospectively recruited 1,161 new AIBD cases diagnosed in Central Serbia during the period from January 1991 to December 2010. The diagnosis was based on strict clinical, histological, and immunohistological evaluation.

RESULTS

The incidence rates were: 4.35 per million population/year (pmp/year) for pemphigus, 4.47 pmp/year for pemphigoid, 1.42 pmp/year for dermatitis herpetiformis (DH), 0.25 pmp/year for linear IgA disease, and 0.08 pmp/year for epidermolysis bullosa acquisita. In the period observed, age-adjusted incidence rates significantly increased for pemphigus and particularly for pemphigoid, whereas they decreased, albeit not significantly, for DH.

CONCLUSIONS

For the first time, our study evaluates the incidence rates of the entire spectrum of AIBDs in Serbia, and examines their temporal trends over a 20-year period. To the best of our knowledge, our finding of similar incidence rates for pemphigus and pemphigoid has previously not been reported.

Ethnic variations in the epidemiology of bullous pemphigoid in Israel

BACKGROUND

No ethnic or geographic predisposition to bullous pemphigoid (BP) was reported so far.

OBJECTIVE

To evaluate trends in the incidence of BP in northern Israel, shedding light on differences between two distinct ethnic populations who inhabit the same region, namely Jews and Arabs.

METHODS

Bullous pemphigoid incidence was retrospectively estimated from January 2000-December 2015 in two Israeli regions with a total population of 1.56 million inhabitants.

RESULTS

A total of 287 new-onset BP patients (mean age: 77.6 ± 12.1) were identified. The incidence rate was 11.4 per million inhabitants per year (95% CI, 10.2-12.9). The crude incidence rate in Jews was 4.8-fold higher than that in Arabs (16.4 vs. 3.4 cases per million per year, respectively [P < 0.0001]). After adjusting for age, the discrepancy between the two populations diminished (11.7 vs. 8.9 cases per million per year, respectively) but remained statistically significant (P = 0.032). The incidence increased consistently from 7.6 cases per million per year in the calendar period 2000-2005 to 12.6 and 14.3 cases in 2006-2010 and 2011-2015, respectively (P < 0.0001). Bullous pemphigoid patients of Arab ancestry presented with the disease significantly earlier than Jews (69.5 ± 15.3 vs. 78.7 ± 11.1 years, respectively, P = 0.002).

CONCLUSIONS

The incidence of BP in northern Israel has increased in the last 16 years and is significantly higher among Jews compared to Arabs. The age of presentation is remarkably different between patients belonging to the two populations.

Incidence of bullous pemphigoid in Sweden 2005-2012: a nationwide population-based cohort study of 3761 patients

Studies that report the incidence of bullous pemphigoid from validated nationwide population-based registries are rare. The aim of this study was to estimate the incidence of bullous pemphigoid in Sweden 2005–2012. A population-based open cohort study was designed including all patients diagnosed by a dermatologist with bullous pemphigoid (BP) in Sweden from 2005 to 2012 (n = 3761), identified from the National Patient Register (NPR). The diagnosis of bullous pemphigoid in the NPR was recently validated from medical records, histopathological and immunopathological data by our group in a previous study. The average annual incidence of bullous pemphigoid was 7.1/100,000 (95% CI 6.5–7.7). Female to male ratio was 1.2:1, mean age at diagnosis was 78.9 years. The age-specific incidence rate increased markedly after 80 years of age with an incidence peak between 90 and 99 years of age, 81.9/100,000 (95% CI 75.0–89.2). This large nationwide cohort study presents an adjusted incidence of BP of 7.1/100,000 (95% CI 6.5–7.7) in Sweden. The incidence of bullous pemphigoid is higher than expected and bullous pemphigoid is a common disease in the elderly population.

The 2016 Bowman Lecture Conjunctival curses: scarring conjunctivitis 30 years on

This review is in two sections. The first section summarises 35 conditions, both common and infrequent, causing cicatrising conjunctivitis. Guidelines for making a diagnosis are given together with the use of diagnostic tests, including direct and indirect immunofluorescence, and their interpretation. The second section evaluates our knowledge of ocular mucous membrane pemphigoid, which is the commonest cause of cicatrizing conjunctivitis in most developed countries. The clinical characteristics, demographics, and clinical signs of the disease are described. This is followed by a review and re-evaluation of the pathogenesis of conjunctival inflammation in mucous membrane pemphigoid (MMP), resulting in a revised hypothesis of the autoimmune mechanisms causing inflammation in ocular MMP. The relationship between inflammation and scarring in MMP conjunctiva is described. Recent research, describing the role of aldehyde dehydrogenase (ALDH) and retinoic acid (RA) in both the initiation and perpetuation of profibrotic activity in MMP conjunctival fibroblasts is summarised and the potential for antifibrotic therapy, using ALDH inhibition, is discussed. The importance of the management of the ocular surface in MMP is briefly summarised. This is followed with the rationale for the use of systemic immunomodulatory therapy, currently the standard of care for patients with active ocular MMP. The evidence for the use of these drugs is summarised and guidelines given for their use. Finally, the areas for research and innovation in the next decade are reviewed including the need for better diagnostics, markers of disease activity, and the potential for biological and topical therapies for both inflammation and scarring.

Clinical features and diagnosis of epidermolysis bullosa acquisita

INTRODUCTION

Epidermolysis bullosa acquisita (EBA) is a rare autoimmune blistering disease of skin and mucous membranes. EBA is caused by autoantibodies against type VII collagen, which is a major component of anchoring fibrils, attaching epidermis to dermis. Binding of autoantibodies to type VII collagen leads to skin fragility and, finally, blister formation. The clinical picture of EBA is polymorphic, with several distinct phenotypes being described. Despite recent progress in understanding the pathophysiology of EBA, its diagnosis is still challenging. Areas covered: This review provides an update on the clinical manifestations and diagnostic methods of EBA. We searched PubMed using the terms 'epidermolysis bullosa acquisita' covering articles in English between 1 January 2005 and 31 May 2016. Relevant older publications were retrieved form cited literature. Expert commentary: While the clinical picture is highly variable, diagnosis relies on direct immunofluorescence (IF) microscopy of a perilesional skin biopsy. Linear deposits of IgG, IgA and/or C3 along the dermal-epidermal junction with an u-serrated pattern are diagnostic for EBA alike the detection of serum autoantibodies against type VII collagen. Several test systems for the serological diagnosis of EBA have recently become widely available. In some patients, sophisticated diagnostic approaches only available in specialized centers are required.

Spectrum of autoimmune vesiculobullous diseases in Iran: a 13-year retrospective study

BACKGROUND

Autoimmune bullous diseases (ABDs) represent a group of rare, acquired disorders characterized by overlapping features with involvement of the skin and mucous membranes, resistance to treatment, and potential lethality that comprise pemphigus, bullous pemphigoid (BP), epidermolysis bullosa, dermatitis herpetiformis, and linear immunoglobulin A bullous dermatosis.

AIM

The main aim of this study was to identify the epidemiologic characteristics and clinical courses of these common diseases in Hamadan, Iran. Few surveys have been carried out to demonstrate the whole spectrum of ABDs in the literature. Notably, in Hamadan we are the first.

MATERIALS AND METHODS

This 13-year retrospective study was designed to evaluate all of documented data obtained from hospitalized patients with ABDs at Farshchian Hospital from October 1999 to October 2012. We collected information on epidemiologic data, clinical aspects, histologic findings, and therapy prescribed. Data were analyzed using SPSS.

RESULTS

Of 168 patients, 78% had pemphigus. The age of patients at presentation ranged from 1 month to 115 years, with a mean of 47.5±19.93 years. Mucosal or skin involvement of ABDs was statistically significant (P<0.001). The incidence of ABDs differed significantly based on anatomic location (P=0.003). We documented three deaths.

CONCLUSION

Compared to previous literature, our findings showed equal epidemiologic properties in Iran. Although pemphigus was the most common ABD followed by BP, it is expected that in line with the global trend, an increase in BP will be driven by population aging in Iran.

Retrospective Study on Autoimmune Blistering Disease in Paediatric Patients

BACKGROUND

Autoimmune blistering diseases (AIBDs) are rare in children and their prevalence in Singapore is unclear. We aimed to investigate the clinical and immunopathologic characteristics of children diagnosed with AIBDs in Singapore.

MATERIALS AND METHODS

The clinical and histology databases at the National Skin Centre in Singapore were searched to identify patients younger than 18 years old diagnosed with an AIBD from January 1, 1998, through December 31, 2012. Patient demographic characteristics, presentation, triggers, investigations, treatments, and disease course were analyzed.

RESULTS

Twelve patients with AIBDs were identified; five (41.7%) had linear immunoglobulin A disease (LAD); two (16.7%) each had pemphigus vulgaris (PV), bullous pemphigoid, and bullous systemic lupus erythematosus; and one (8.3%) had pemphigus foliaceus. Four (33.3%) were female and eight (66.7%) male. The mean age of onset was 8.7 years (range 2-17 years). Most patients were treated with steroids and adjuvant immunosuppressants. Intravenous rituximab was used effectively in a patient with recalcitrant PV. The mean follow-up was 2.35 years (range 0.17-7.33 years). As of the last follow-up, four (33.3%) patients were in complete remission off therapy, two (16.7%) were in complete remission on therapy, four (33.3%) were in partial remission on therapy, and two (16.7%) were lost to follow-up.

CONCLUSION

Consistent with the existing literature, our study shows that LAD is the most common cause of AIBDs in children. Although common in the West, dermatitis herpetiformis was not identified in the current study. Intravenous rituximab may be considered in recalcitrant childhood PV, but vigilant monitoring for side effects is crucial. Immunohistopathologic evaluation is important and repeat biopsies may be of value in patients with atypical disease courses.

Immune mechanism-targeted treatment of experimental epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita (EBA) is an autoimmune bullous dermatosis characterized by chronic mucocutaneous blistering caused by autoantibodies directed against type VII collagen. EBA causes a high morbidity and is difficult to treat. Model systems have significantly broadened our understanding of EBA pathogenesis, leading to the identification of numerous therapeutic targets. Of these, so far, a few have been evaluated for their therapeutic potential in preclinical models. In mice, EBA can be induced by transfer of anti-type VII collagen antibodies or by immunization with the protein. The latter model, immunization-induced EBA, is ideal to test drugs for their therapeutic efficacy. Here, mice with already established disease can be treated for prolonged periods. Albeit time consuming, results from immunization-induced EBA will pave the way for clinical application in patients. As the key pathogenic principle, that is, autoantibody-induced, leukocyte-mediated tissue injury and inflammation, is shared by other diseases, these findings may have translational applications beyond EBA.

Epidermolysis bullosa acquisita in a 17-year-old boy with Crohn's disease

Epidermolysis bullosa acquisita is a rare, acquired, autoimmune subepidermal blistering disease of the skin, characterised by blisters and erosions, especially in trauma-prone sites and extensor skin surface, scarring with formation of milia, skin fragility and nail dystrophy. Epidermolysis bullosa acquisita is extremely rare in childhood and it has been reported to be frequently associated with Crohn's disease. Furthermore, autoantibodies against type VII collagen have been found in a large number of patients with Crohn's disease without epidermolysis bullosa acquisita. We report a case of a 17-year-old boy affected by Crohn's disease who presented with milia on infiltrated erythematous plaques over the back of the hands. The diagnosis of epidermolysis bullosa acquisita was confirmed by histopathology, direct and indirect immunofluorescence analysis and ELISA.

A retrospective review of the therapeutic response with remission in patients with newly diagnosed bullous pemphigoid

We reviewed the clinical characteristics and therapeutic response in cases of newly diagnosed bullous pemphigoid at the National Skin Centre between June 2009 and December 2010. Most (76%, n = 68/90) achieved clinical remission within 6 months of commencement of therapy. Oral mucosal involvement was identified as a risk factor associated with a prolonged duration of treatment beyond 6 months.

Autoimmune blistering diseases in females: a review

The autoimmune blistering diseases (AIBDs) are a group of heterogeneous skin diseases with autoantibodies directed against structural proteins in the skin. A new interest in the female bias towards autoimmune diseases in general has led to our attention to focus on how and why this female bias manifests in AIBD. The authors aim to review and explore the various aspects of AIBD affecting females more than males, including the higher prevalence, worse quality of life, and complex management issues such as pregnancy and lactation.

What is already known on this topic?

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Echoing autoimmune diseases in general, most autoimmune blistering diseases (AIBDs) have a female predominance, but the exact level of predominance is unknown.

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Pregnancy raises several complicated management issues for females with an AIBD.

What does this article add to our knowledge?

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Review of sex-specific epidemiology and etiology of each AIBD.

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Exploration and explanation of the key factors underlying the detrimental impacts of AIBD on women’s quality of life (QOL).

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Discussion of management issues in pregnancy and lactation for females with an AIBD.

How does this information impact clinical practice and/or change patient care?

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An awareness and understanding of the female predominance in AIBDs will ensure more appropriate diagnosis, evaluation, and future research.

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Emphasizing holistic care targeting the debilitating effects of AIBDs on women’s QOL.

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Informing the reader of optimal, yet safe interventions for pregnant women with an AIBD.

Geographic variations in epidemiology of two autoimmune bullous diseases: pemphigus and bullous pemphigoid

Autoimmune bullous diseases are rare, organ-specific, a group of blistering disease of skin and mucous membranes. Recent studies suggest that the frequency of the autoimmune bullous diseases has been increasing. Pemphigus vulgaris and bullous pemphigoid are the most frequently reported autoimmune bullous diseases. High incidence of autoimmune bullous diseases in some ethnic groups such as pemphigus in Ashkenazi Jewish, or in some regions such as pemphigus foliaceus in Brazil has been shown to be related to genetic and environmental factors, respectively. Pemphigus has been reported more frequently in the female gender. Although it is most frequently diagnosed between the ages 50 and 60 in European countries, in the remaining countries in the world, it is seen between the ages of 30 and 50. Bullous pemphigoid is generally seen above 70 years of age. Although overall incidence is slightly higher in females, after the age of 80 years it is more frequent in males. Both pemphigus vulgaris and bullous pemphigoid has a chronic course with recurrences. Mortality risk of the patients with bullous pemphigoid was found at least 2 times higher and the mortality risk of the patients with pemphigus was found approximately 3 times higher than that of the general population. In this review, the results obtained from the epidemiological studies were analyzed according to geographic regions, and especially epidemiologic features of two prevalent autoimmune bullous diseases, pemphigus and bullous pemphigoid have been discussed.

A Cross-sectional Study of Direct Immunofluorescence in the Diagnosis of Immunobullous Dermatoses

Background:

Autoimmune blistering diseases are a group of bullous disorders characterized by pathogenic antibodies directed at the target antigens, which are components of the desmosomes or adhesion complex at the dermoepidermal junction. Direct immunofluorescence (DIF) is invaluable in the diagnosis of these lesions.

Aim:

The aim of this study was to evaluate the sensitivity of DIF in immunobullous dermatoses and to study the pattern of DIF. The study also aims to correlate DIF with clinical and histologic findings and to analyze discrepancies.

Materials and Methods:

Total 100 biopsies received over a period of 2 years in the Department of Pathology were analyzed. DIF, histopathology and clinical data were reviewed.

Results:

Out of 100, 89 cases showed DIF patterns concordant with clinical/histologic diagnosis. The sensitivity of DIF was 94.44% (51/58) in the pemphigus and 84% (21/25) in the bullous pemphigoid (BP) group, 100% each in dermatitis herpetiformis (2/2) and linear IgA disease (1/1). A total of 11 histologically proven cases of immunobullous lesions were DIF negative-four (three of pemphigus vulgaris and one of BP) due to having no epidermis, three (cases of BP) owing to sampling/technical errors and the remaining four (cases of pemphigus vulgaris) due to being on treatment.

Conclusion:

Immunofluorescence helps confirm the diagnosis of bullous lesions in which there is clinical and the histopathologic overlap. Sampling errors contributed to false negative (FN) results.

Mortality of bullous pemphigoid in Singapore: risk factors and causes of death in 359 patients seen at the National Skin Centre

BACKGROUND

Bullous pemphigoid (BP) is the most common autoimmune-mediated subepidermal blistering skin disease and is associated with significant morbidity and mortality.

OBJECTIVES

To determine the 3-year mortality rate, risk factors and causes of death in patients with BP in Singapore, compared with the general population.

METHODS

We conducted a retrospective cohort study of all newly diagnosed patients with BP seen at the National Skin Centre from 1 April 2004 to 31 December 2009. Demographic and clinical data on comorbidities and treatment were recorded. Mortality information was obtained from the National Registry of Diseases.

RESULTS

In total 359 patients were included in our study. The 1-, 2-, 3-year mortality rates were 26·7%, 38·4% and 45·7%, respectively. The 3-year standardized mortality risk for patients with BP was 2·74 (95% confidence interval 2·34-3·19) times higher than for the age- and sex-matched general population. Parkinson disease, heart failure and chronic renal disease were associated with increased mortality, while combination treatment with low-to-moderate-dose corticoste-roids and immunomodulatory agents such as doxycycline and/or nicotinamide was associated with lower mortality. Overall, infections were the most common cause of death (59·8%), with the main causes of death being pneumonia (42·7%), cardiovascular disease (14·6%) and stroke (11·6%).

CONCLUSIONS

This study confirms an increased 3-year mortality rate for patients with BP in Singapore. Risk factors for increased mortality include medical comorbidities, especially neurological, cardiac and renal diseases. Treatment with combination therapy, including the use of low-to-moderate-dose corticosteroid, appeared to decrease mortality risk in patients with BP.

Clinical presentation, pathogenesis, diagnosis, and treatment of epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita (EBA) is a chronic mucocutaneous autoimmune skin blistering disease. The pathogenic relevance of autoantibodies targeting type VII collagen (COL7) has been well-documented. Therefore, EBA is a prototypical autoimmune disease with a well-characterized pathogenic relevance of autoantibody binding to the target antigen. EBA is a rare disease with an incidence of 0.2 new cases per million and per year. The current treatment of EBA relies on general immunosuppressive therapy, which does not lead to remission in all cases. Therefore, there is a high, so far unmet medical need for the development of novel therapeutic options. During the last 10 years, several novel in vitro and in vivo models of EBA have been established. These models demonstrated a critical role of the genetic background, T cells, and cytokines for mediating the loss of tolerance towards COL7. Neutrophils, complement activation, Fc gamma receptor engagement, cytokines, several molecules involved in cell signaling, release of reactive oxygen species, and matrix metalloproteinases are crucial for autoantibody-induced tissue injury in EBA. Based on this growing understanding of the diseases' pathogenesis, several potential novel therapeutic targets have emerged. In this review, the clinical presentation, pathogenesis, diagnosis, and current treatment options for EBA are discussed in detail.

Pemphigoid diseases

Pemphigoid diseases are a group of well defined autoimmune disorders that are characterised by autoantibodies against structural proteins of the dermal-epidermal junction and, clinically, by tense blisters and erosions on skin or mucous membranes close to the skin surface. The most common of these diseases is bullous pemphigoid, which mainly affects older people and the reported incidence of which in Europe has more than doubled in the past decade. Prognosis and treatments vary substantially between the different disorders and, since clinical criteria are usually not sufficient, direct immunofluorescence microscopy of a perilesional biopsy specimen or serological tests are needed for exact diagnosis. In eight pemphigoid diseases the target antigens have been identified molecularly, which has allowed the development of standard diagnostic assays for detection of serum autoantibodies-some of which are commercially available. In this Seminar we discuss the clinical range, diagnostic criteria, diagnostic assay systems, and treatment options for this group of diseases.

Linear immunoglobulin A bullous dermatosis

Linear immunoglobulin A (IgA) bullous dermatosis, also known as linear IgA disease, is an autoimmune mucocutaneous disorder characterized by subepithelial bullae, with IgA autoantibodies directed against several different antigens in the basement membrane zone. Its immunopathologic characteristic resides in the presence of a continuous linear IgA deposit along the basement membrane zone, which is clearly visible on direct immunofluorescence. This disorder shows different clinical features and distribution when adult-onset of linear IgA disease is compared with childhood-onset. Diagnosis is achieved via clinical, histopathologic, and immunopathologic examinations. Two common therapies are dapsone and sulfapyridine, which reduce the inflammatory response and achieve disease remission in a variable period of time.

Black patients of African descent and HLA-DRB1*15:03 frequency overrepresented in epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita (EBA) is a rare autoimmune bullous disease (AIBD). However, higher EBA incidence and predisposing genetic factor(s) involving an HLA haplotype have been suspected in some populations. This retrospective study assessed the overrepresentation of black patients with EBA, its link with HLA-DRB1*15:03, and their clinical and immunological characteristics. Between 2005 and 2009, 7/13 (54%) EBA and 6/183 (3%) other-AIBD patients seen consecutively in our department were black (P=10(-6)); moreover 7/13 (54%) black patients and 6/183 (3%) white patients had EBA (P=10(-6)). In addition, between 1983 and 2005, 12 black patients had EBA. Finally, among the 19 black EBA patients, most of them had very atypical clinical presentations, 9 were natives of sub-Saharan Africa, 1 from Reunion Island, 7 from the West Indies, and 2 were of mixed ancestry. HLA-DRB1*15:03 allelic frequencies were 50% for African patients, significantly higher than the control population (P<10(-3)), and 21% for the West Indians (nonsignificant). High EBA frequencies have already been reported in American blacks significantly associated with the HLA-DR2. In conclusion, black-skinned patients developing EBA seem to have a genetic predisposition, and EBA should be suspected systematically for every AIBD seen in this population.