Diagnosis of Autoimmune Blistering Diseases

MicroRNAs in patients with pemphigus: A systematic review

BACKGROUND

Pemphigus is a group of rare and severe autoimmune blistering diseases (AIBDs). MicroRNA's role in the pathogenesis of pemphigus disease has been previously studied, but MicroRNAmicroRNAs research in dermatology is still at its beginning.

METHODS

This review was carried out using a systematic search on PubMed, Scopus Embase, and Web of Science from 1990 to February 2025 to explore the role of microRNA in the diagnosis and severity evaluation of pemphigus disease.

RESULTS

A total of 8 studies were identified in the systematic review that indicated the expression level of 18 types of microRNA was significantly different from that of healthy people.

CONCLUSIONS

The collective data presented in this review indicate that MicroRNAmicroRNAs may help diagnose and predict the course of pemphigus, while the clinical application of these findings has yet to be verified.

Diagnostic methods and strategies for autoimmune bullous diseases

INTRODUCTION

Autoimmune bullous disease (AIBD), showing blistering lesions on the skin and/or mucous membranes, is characterized by autoantibodies against various structural molecules present in keratinocyte cell surfaces and epidermal basement membrane zone. In addition to the clinical and pathological features, identification of specific autoantibodies is essential for AIBD diagnosis, and therefore corresponding methods should be well summarized and popularized.

AREA COVERED

Currently, direct immunofluorescence using biopsy tissue specimen and indirect immunofluorescence using normal human skin, 1 M NaCl-split skin and rat bladder are primarily used to identify tissue-bound and circulating autoantibodies, respectively. Immunoblotting and enzyme-linked immunosorbent assay (ELISA) methods have been developed for detection of autoantibodies against AIBD autoantigens, including desmoglein 1, desmoglein 3, BP180, BP230, type VII collagen, laminin (LM) 332, integrin α6β4, p200 (LMγ1/LMβ4) and human serum albumin. In this review, we summarized the detailed laboratory protocols for AIBD diagnosis methods used in our three institutes (Kurume University and Osaka Metropolitan University in Japan, and Daqing Oilfield General Hospital in China) before 9 October 2024.

EXPERT OPINION

This review will benefit both clinical practitioners and basic researchers on AIBD. In the future, simpler and easier AIBD diagnostic algorithms using a smaller number of tests should be established.

Recurrent balanoposthitis and oral blistering in a young man

A 35-year-old man presented with a clinical history of recurrent blisters on the genital skin and oral mucosa. Lesions had started 3 years previously on the glans penis, with painful swelling, blistering and sloughing and a 2-year history of alternating activity/remitting symptoms. In the past year, painless blisters had developed on his hard palate. He had experienced painful eyes for 3 years.

From Pruritus to Bullae: Recognizing Furosemide-Induced Bullous Pemphigoid in an Elderly Male Patient

Bullous pemphigoid (BP) is an autoimmune blistering disorder characterized by tense bullae and severe generalized pruritus. However, atypical presentations in elderly patients may involve localized pruritus prior to the development of bullae, which can obscure the diagnosis and delay appropriate treatment. We present a case of BP induced by furosemide in an 83-year-old male patient with congestive heart failure. The patient initially experienced persistent pruritus on the bilateral arms and back, which emerged approximately three months after initiating furosemide therapy. This pruritus was initially attributed to xerosis. Subsequently, erythematous papules developed in these areas, raising suspicion for atypical scabies, although they did not respond to permethrin treatment. A shave biopsy revealed subepidermal bullous disease with numerous eosinophils, and direct immunofluorescence confirmed the diagnosis of BP, showing linear IgG and granular C3 deposition at the basement membrane zone. The papules then evolved into tense bullae, and serologic testing supported the diagnosis with elevated IgG titers and positive BP180 antibodies. Furosemide was discontinued as the likely trigger. Initial treatment with prednisone led to improvement; however, bullae reappeared upon tapering the medication. Further management with doxycycline and topical triamcinolone resulted in enhanced improvement. Ultimately, biweekly dupilumab injections effectively controlled the symptoms. This case underscores the diagnostic challenges of BP, particularly in the elderly, where isolated pruritus may precede the appearance of visible bullous lesions. Clinicians should maintain a high index of suspicion for BP in elderly patients with unexplained pruritus, especially when standard treatments are ineffective. Additionally, this case highlights the importance of considering drug-induced BP, with furosemide recognized as a potential trigger.

The Role of Nutrition in the Pathogenesis and Treatment of Autoimmune Bullous Diseases-A Narrative Review

Autoimmune bullous diseases (AIBDs) are a group of conditions marked by the formation of blisters and erosions on the skin and mucous membranes. It occurs in all age groups, slightly more often affecting women. Several factors may be linked to the development of AIBDs, with nutrition being one of them. The literature mentions various food products and food ingredients acting as disease modifiers. Given the complex relationship between bullous diseases and nutrition, the current literature on AIBDs has been reviewed, with an emphasis on the influence of dietary modifications, various diets, and the nutritional consequences of these conditions. This review summarizes the role of nutrition in the pathogenesis and treatment of the following AIBDs: (i) pemphigus, (ii) bullous pemphigoid and mucous membrane pemphigoid, (iii) dermatitis herpetiformis, and (iv) epidermolysis bullosa acquisita. Several nutrients and dietary factors have been studied for their potential roles in triggering or exacerbating AIBDs. The key nutrients and their potential impacts include thiols and bulb vegetables (Allium), phenols, tannic acid, tannins, phycocyanin, isothiocyanates, all trans-retinoic acids, cinnamic acid, and walnut antigens. Many patients with ABIDs may require supplementation, particularly of vitamin D and B3, calcium, potassium, zinc, selenium, and cobalt. In addition, various diets play an important role. A soft diet is recommended for individuals with issues in the oral cavity and/or esophagus, particularly for those who experience difficulties with biting or swallowing. This approach is commonly used in managing pemphigus. A high-protein, high-calcium diet, DASH (Dietary Approaches to Stop Hypertension), and the Mediterranean diet are utilized during long-term glucocorticoid therapy. However, in dermatitis herpetiformis it is advisable to follow a gluten-free diet and eliminate iodine from the diet. When it comes to herbal supplements, Algae (Spirulina platensis), Echinacea, and St. John's wort (Hyperitum perforatum) enhance the ABIDs, while Cassia fistula may be recommended in the treatment of erosions in pemphigus vulgaris. Fast foods enhance the development of ABIDs. However, the pathomechanism is not yet fully understood. Future researchers should more precisely define the relationships between nutrients and nutrition and blistering diseases by also looking at, i.e., genetic predispositions, microbiome differences, or exposure to stress.

Pemphigus Foliaceus Mimicking Ichthyosis: A Rare Clinical Presentation

Pemphigus foliaceus (PF) is an autoimmune blistering disease characterized by the disruption of the epidermal cell adhesion protein desmoglein 1 (DsG1). PF classically presents with superficial erosions or blisters, but can rarely mimic other dermatological conditions, which makes diagnosis challenging. We report the case of a 57-year-old Sri Lankan man with a one-month history of widespread ichthyosis-like plaques and scales which started on his scalp and progressed in a cranio-caudal fashion and were associated with pruritus and few blisters. Histopathology revealed features consistent with PF, and immunofluorescence studies further confirmed the diagnosis of PF. This case highlights the atypical presentation of PF resembling ichthyosis, emphasizing the need to consider autoimmune blistering diseases for unexplained scaling dermatoses. The unusual nature of PF presenting with ichthyosis-like scaly plaques highlights the need for further research. Accurate early diagnosis and treatment can both significantly improve outcomes.

HLA-Cw6 Polymorphism in Autoimmune Blistering Diseases

Autoimmune blistering diseases of the pemphigus and pemphigoid groups are immune-mediated disorders due to circulating pathogenetic autoantibodies. Multiple human leukocyte antigen (HLA) genes have been associated with predisposition to these disorders. HLA-Cw6 is involved in antigen presentation processes and has been linked to psoriasis. The aim of our study was to investigate the association between the presence of the HLA-Cw6 allele and susceptibility to pemphigus vulgaris and bullous pemphigoid. A genetic study in vitro with a cross-sectional design was performed enrolling forty patients with pemphigus vulgaris and forty patients with bullous pemphigoid. The detection of HLA-Cw6 was performed through the EUROArray test on DNA obtained from whole blood samples. The polymorphism was detected in 3/40 genotypes in the pemphigus vulgaris group and in 4/40 genotypes of patients with bullous pemphigoid, unveiling a non-statistically significant different frequency in pemphigus (p = 0.6368) and in pemphigoid (p = 0.62) compared to the reference frequency from the literature of 0.086. Further research is needed to better investigate the role of HLA-Cw6 in immune-mediated diseases and to identify novel genetic markers associated with susceptibility to autoimmune blistering diseases and with disease severity and response to immunosuppressive therapies.

C3d Immunohistochemical Staining on Paraffin-Embedded Tissue for Diagnosis of Pemphigus

CONTEXT.—

Pemphigus is an autoimmune blister disease that causes blisters on the skin and mucosal surfaces. Direct immunofluorescence (DIF) testing is critical for the clinical diagnosis of pemphigus. However, it is limited to fresh tissue specimens and fluorescence microscopy.

OBJECTIVE.—

To assess the value of C3d immunohistochemistry (IHC) on paraffin-embedded skin tissue for the diagnosis of pemphigus by comparing C3d-IHC results to DIF and enzyme-linked immunosorbent assay testing in pemphigus and other blister-related skin diseases.

DESIGN.—

C3d-IHC assays were retrospectively performed on paraffin-embedded skin tissue sections from 115 patients (63 with pemphigus and 52 controls). Both the case group and the control group underwent the same protocol, and cases with C3d position in the peripheral spinous layer were considered as positive samples.

RESULTS.—

C3d-IHC and DIF testing had similar performance for pemphigus diagnosis, with a sensitivity of 71.0% (95% CI, 51.8%-85.1%) and 77.4% (95% CI, 58.5%-89.7%), specificity of 96.4% (95% CI, 79.8%-99.8%) and 100% (95% CI, 85.0%-100%), positive predictive value of 95.7% (95% CI, 76.0%-99.8%) and 100% (95% CI, 82.8%-100%), and a negative predictive value of 75.0% (95% CI, 57.5%-87.3%) and 80.0% (95% CI, 62.5%-90.9%), respectively.

CONCLUSIONS.—

Our study indicated that C3d-IHC results for paraffin-fixed tissues were not significantly different from DIF results for the diagnosis of pemphigus. The C3d-IHC assay has the potential for routine diagnosis of pemphigus, especially in the absence of fresh-frozen tissue.

Dapsone as a Current Option for the Treatment of Autoimmune Bullous Diseases with Autoimmunity to Non-Enzymes: A Retrospective Study from a Single Central European Referral Center

Background and Objectives: Dapsone (DP) is employed in the management of various skin conditions, including autoimmune bullous diseases to non-enzymes (n-eAIBDs). This study aimed to assess the advantages and safety profile of DP treatment in n-eAIBDs patients. The evaluation focused on clinical remission, reduction in glucocorticosteroid (GCS) usage, and adverse incidents during a 12-month observation in a dermatology department at a Central European university. Materials and Methods: Our retrospective study included forty-one patients who met the inclusion criteria, comprising nineteen with pemphigus vulgaris, nine with pemphigus foliaceus, four with bullous pemphigoid, and nine with mucous membrane pemphigoid, including one patient with Brunsting-Perry pemphigoid. Patients received 25-50 mg/day of DP along with oral GCSs for a year, with a subsequent dose reduction where feasible. Results: The mean decreases in prednisone-equivalent dosages across all groups after 2, 6, and 12 months of DP treatment were 45.66%, 65.77%, and 63.03%, respectively. Throughout the 12-month observation period, 21.62% of patients experienced a relapse, while the remaining patients attained either complete or partial remission with minimal therapy. Adverse incidents were observed in 29.27% of patients; these were mild or moderate, and no severe negative effects were observed. Conclusions: DP is an effective and affordable choice to support the treatment of n-eAIBDs, but it may not be sufficient for long-term management in certain patients with severe n-eAIBDs.

State-of-the-art diagnosis of autoimmune blistering diseases

Autoimmune blistering disorders (AIBDs) are a heterogeneous group of approximately a dozen entities comprising pemphigus and pemphigoid disorders and dermatitis herpetiformis. The exact diagnosis of AIBDs is critical for both prognosis and treatment and is based on the clinical appearance combined with the detection of tissue-bound and circulating autoantibodies. While blisters and erosions on the skin and/or inspectable mucosal surfaces are typical, lesions may be highly variable with erythematous, urticarial, prurigo-like, or eczematous manifestations. While direct immunofluorescence microscopy (IFM) of a perilesional biopsy is still the diagnostic gold standard, the molecular identification of the major target antigens opened novel therapeutic avenues. At present, most AIBDs can be diagnosed by the detection of autoantigen-specific serum antibodies by enzyme-linked immunosorbent assay (ELISA) or indirect IFM when the clinical picture is known. This is achieved by easily available and highly specific and sensitive assays employing recombinant immunodominant fragments of the major target antigens, i.e., desmoglein 1 (for pemphigus foliaceus), desmoglein 3 (for pemphigus vulgaris), envoplakin (for paraneoplastic pemphigus), BP180/type XVII collagen (for bullous pemphigoid, pemphigoid gestationis, and mucous membrane pemphigoid), laminin 332 (for mucous membrane pemphigoid), laminin β4 (for anti-p200 pemphigoid), type VII collagen (for epidermolysis bullosa acquisita and mucous membrane pemphigoid), and transglutaminase 3 (for dermatitis herpetiformis). Indirect IFM on tissue substrates and in-house ELISA and immunoblot tests are required to detect autoantibodies in some AIBD patients including those with linear IgA disease. Here, a straightforward modern approach to diagnosing AIBDs is presented including diagnostic criteria according to national and international guidelines supplemented by long-term in-house expertise.

Frequency of infections during rituximab treatment of autoimmune blistering diseases

This study investigates the frequency of infections in autoimmune blistering disease (AIBD) patients treated with rituximab and evaluates the difference in infectious complications in patients on concomitant antibiotic and/or antiviral prophylaxis. The study retrospectively reviewed 43 AIBD patients who received rituximab over a five-year interval. The patients were categorized based on prophylaxis type (antibiotic, antiviral, or both) and concomitant immunosuppression status, which we defined as treatment with an immunosuppressive medication during the time frame they were given Rituximab. Our findings suggest that concomitant immunosuppression alongside rituximab did not significantly increase the risk of developing infectious complications compared to rituximab monotherapy. Results revealed that 34.4% of patients with concomitant immunosuppression had a secondary bacterial infection, defined as bacterial complications requiring hospitalization, consistent with prior studies. Moreover, antibiotic prophylaxis did not significantly reduce infection risk in patients on rituximab, with 45.1% of these patients experiencing bacterial complications. There was an absence of pneumocystis pneumonia in the study population. Despite the small sample size and limited timeline, this study suggests that antibiotic prophylaxis may not significantly mitigate the risk of infections in AIBD patients receiving rituximab, and the risk of infection with concomitant immunosuppression with rituximab requires additional investigation for definitive causal risk.

New Onset and Exacerbation of Autoimmune Bullous Dermatosis Following COVID-19 Vaccination: A Systematic Review

BACKGROUND

Cases of autoimmune bullous dermatosis (AIBD) have been reported following COVID-19 vaccination.

OBJECTIVE

We aimed to provide an overview of clinical characteristics, treatments, and outcomes of AIBDs following COVID-19 vaccination.

METHODS

We conducted a systematic review and searched the Embase, Cochrane Library, and Medline databases from their inception to 27 March 2024. We included all studies reporting ≥ 1 patient who developed new-onset AIBD or experienced flare of AIBD following at least one dose of any COVID-19 vaccine.

RESULTS

We included 98 studies with 229 patients in the new-onset group and 216 in the flare group. Among the new-onset cases, bullous pemphigoid (BP) was the most frequently reported subtype. Notably, mRNA vaccines were commonly associated with the development of AIBD. Regarding the flare group, pemphigus was the most frequently reported subtype, with the mRNA vaccines being the predominant vaccine type. The onset of AIBD ranged from 1 to 123 days post-vaccination, with most patients displaying favorable outcomes and showing improvement or resolution from 1 week to 8 months after treatment initiation.

CONCLUSIONS

Both new-onset AIBD and exacerbation of pre-existing AIBD may occur following COVID-19 vaccination. Healthcare practitioners should be alert, and post-vaccination monitoring may be essential.

Clinical Significance of Uncommon, Non-Clinical, and Novel Autoantibodies

Autoantibodies are a common mark of autoimmune reaction and their identification in the patients' serum, cerebrospinal fluid, or tissues is generally believed to represent diagnostic or prognostic biomarkers of autoimmune diseases or autoinflammatory conditions. Traditionally, autoantibody testing is an important part of the clinical examination of suspected patients, and in the absence of reliable T cell tests, characterization of autoantibody responses might be suitable in finding causes of specific autoimmune responses, their strength, and sometimes commencement of autoimmune disease. Autoantibodies are also useful for prognostic stratification in clinically diverse groups of patients if checked repeatedly. Antibody discoveries are continuing, with important consequences for verifying autoimmune mechanisms, diagnostic feasibility, and clinical management. Adding newly identified autoantibody-autoantigen pairs to common clinical laboratory panels should help upgrade and harmonize the identification of systemic autoimmune rheumatic disorders and other autoimmune conditions. Herein, we aim to summarize our current knowledge of uncommon and novel autoantibodies in the context of discussing their validation, diagnostic practicability, and clinical relevance. The regular updates within the field are important and well justified.

Evaluation of Dry Eye Severity and Ocular Surface Inflammation in Patients with Pemphigus and Pemphigoid

PURPOSE

To evaluate ocular surface involvement, tear cytokine levels, and histopathological changes in pemphigus and pemphigoid patients.

METHODS

A total of 22 patients (15 pemphigus and 7 pemphigoids) and 21 non-diseased controls were enrolled in our study. All participants underwent ocular surface evaluation, which included ocular surface disease index test, slit lamp observation, dry eye-related examination, tear multicytokine analysis, and conjunctival impression cytology.

RESULTS

Pemphigus and pemphigoid patients presented much more severe conjunctivochalasis, corneal epithelial defects, corneal opacity, symblepharon   and dry eye. Severe ocular surface squamous metaplasia and a significant increase of tear macrophage inflammatory protein-1beta, tumor necrosis factor-alpha, interleukin (IL)-1β, IL -6, and IL-8 occurred in pemphigus and pemphigoid patients.

CONCLUSIONS

Our results revealed that ocular surface inflammation and dry eye persist in most pemphigus and pemphigoid patients, and do not occur in parallel with the systemic course. Regular ophthalmological examinations and local anti-inflammatory should be provided for pemphigus and pemphigoid patients.

Diagnostic Techniques in Autoimmune Blistering Diseases

Autoimmune blistering diseases (AIBD) comprise a heterogeneous group of uncommon disorders of the skin and mucous membranes, characterised by antibodies targeting structural proteins within epithelial tissue and the underlying basement membrane. There can be significant overlap in clinical presentation of these diseases and accurate diagnosis relies on the detection and characterisation of relevant autoantibodies. Immunofluorescence provides the gold-standard diagnostic tool for these diseases, identifying both tissue-bound autoantibodies in biopsy material using direct immunofluorescence and circulating antibodies in serum through indirect immunofluorescence. Following advances in the identification and subsequent characterisation of numerous antigenic targets in these diseases, the development of antigen-specific tests, in particular, enzyme-linked immunosorbent assays on serum specimens, has provided a third key tool to not only identify, but also quantify AIBD autoantibodies. This quantification has proven particularly useful in monitoring disease activity and informing clinical management decisions. Accurate diagnosis of these diseases is important since optimal treatment strategies differ between them and, prognostically, some diagnoses are associated with an increased risk of malignancy. This review outlines the molecular pathology underlying the major AIBD and describes how the three principal techniques can be used in combination, to provide best practice for diagnosis and treatment monitoring.

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.

[Pemphigoid diseases in older adults]

Pemphigoid diseases are a group of bullous autoimmune diseases characterized by autoantibodies against structural proteins of the dermal-epidermal junction. With a steadily growing aging population, pemphigoid diseases are emerging as a significant medical challenge, because they occur primarily in older individuals. The by far most common disease is bullous pemphigoid, which is clinically characterized by tense blisters, erosions, erythema or urticarial plaques, while severe pruritus is the leading subjective symptom. Mucous membrane pemphigoid predominantly affects surface-close mucous membranes with painful erosions and blisters as well as frequently scarring usually in the mouth, nose, and eyes. Anti-p200 pemphigoid clinically resembles bullous pemphigoid but is much less common. Diagnosis of these diseases involves the combination of clinical evaluation, lesional histopathology, direct immunofluorescence microscopy of a perilesional biopsy and serology. Topical and systemic corticosteroids are the mainstay of pemphigoid diseases treatment. Depending on the severity of the disease, various potentially corticosteroid-sparing therapies, such as dapsone, doxycycline, methotrexate, azathioprine and mycophenolate may be used. In severe courses, treatment with rituximab, cyclophosphamide, intravenous immunoglobulins or immunoadsorption are second- or third-line treatment options. Patients are best managed in centers experience with the management of pemphigoid diseases. Updated national and international guidelines for the diagnosis and treatment of bullous pemphigoid and mucous membrane pemphigoid have recently been published.

S2k guidelines on the management of paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome initiated by the European Academy of Dermatology and Venereology (EADV)

BACKGROUND

Paraneoplastic pemphigus (PNP), also called paraneoplastic autoimmune multiorgan syndrome (PAMS), is a rare autoimmune disease with mucocutaneous and multi-organ involvement. PNP/PAMS is typically associated with lymphoproliferative or haematological malignancies, and less frequently with solid malignancies. The mortality rate of PNP/PAMS is elevated owing to the increased risk of severe infections and disease-associated complications, such as bronchiolitis obliterans.

OBJECTIVES

These guidelines summarize evidence-based and expert-based recommendations (S2k level) for the clinical characterization, diagnosis and management of PNP/PAMS. They have been initiated by the Task Force Autoimmune Blistering Diseases of the European Academy of Dermatology and Venereology with the contribution of physicians from all relevant disciplines. The degree of consent among all task force members was included.

RESULTS

Chronic severe mucositis and polymorphic skin lesions are clue clinical characteristics of PNP/PAMS. A complete assessment of the patient with suspected PNP/PAMS, requiring histopathological study and immunopathological investigations, including direct and indirect immunofluorescence, ELISA and, where available, immunoblotting/immunoprecipitation, is recommended to achieve a diagnosis of PNP/PAMS. Detection of anti-envoplakin antibodies and/or circulating antibodies binding to the rat bladder epithelium at indirect immunofluorescence is the most specific tool for the diagnosis of PNP/PAMS in a patient with compatible clinical and anamnestic features. Treatment of PNP/PAMS is highly challenging. Systemic steroids up to 1.5 mg/kg/day are recommended as first-line option. Rituximab is also recommended in patients with PNP/PAMS secondary to lymphoproliferative conditions but might also be considered in cases of PNP/PAMS associated with solid tumours. A multidisciplinary approach involving pneumologists, ophthalmologists and onco-haematologists is recommended for optimal management of the patients.

CONCLUSIONS

These are the first European guidelines for the diagnosis and management of PNP/PAMS. Diagnostic criteria and therapeutic recommendations will require further validation by prospective studies.

Skin disorders and interstitial lung disease: Part II-The spectrum of cutaneous diseases with lung disease association

Part 2 of this 2-part CME introduces dermatologists to noninfectious inflammatory skin diseases associated with pulmonary involvement. In many cases, dermatologists may be the first physicians recognizing respiratory complications associated with these diagnoses. Because pulmonary involvement is often the leading cause of morbidity and mortality, dermatologists should be comfortable screening and monitoring for lung disease in high-risk patients, recognizing cutaneous stigmata of lung disease in these patients and referring to pulmonary specialists, when appropriate, for prompt treatment initiation. Some treatments used for skin disease may not be appropriate in the context of lung disease and hence, choosing a holistic approach is important. Interstitial lung disease and pulmonary hypertension are the most common pulmonary complications and a significant cause of mortality in autoimmune connective tissue diseases, especially systemic sclerosis, dermatomyositis, and mixed connective tissue disease. Pulmonary complications, notably interstitial lung disease, are also common and life-threatening in sarcoidosis and vasculitis, while they are variable in neutrophilic and autoimmune blistering diseases.

Risk factors and sequelae of epidermolysis bullosa acquisita: A propensity-matched global study in 1,344 patients

Identification of risk factors and sequelae of any given disease is of key importance. For common diseases, primary prevention and disease management are based on this knowledge. For orphan diseases, identification of risk factors and sequelae has been challenging. With the advent of large databases, e.g., TriNetX, this can now be addressed. We used TriNetX to identify risk factors and sequelae of epidermolysis bullosa acquisita (EBA), a severe and orphan autoimmune disease. To date, there is only enigmatic information on EBA comorbidity. We recruited 1,344 EBA patients in the Global Collaborative Network of TriNetX. Using the "explore outcomes" function we identified 55 diagnoses with a different prevalence between EBA and no-EBA patients. We next performed propensity-matched, retrospective cohort studies in which we determined the risk of EBA development following any of the identified 55 diseases. Here, 31/55 diseases were identified as risk factors for subsequent EBA. Importantly, the highest risk for EBA were other chronic inflammatory diseases (CID), especially lupus erythematosus and lichen planus. Lastly, we determined the risk to develop any of the identified diseases after EBA diagnosis. Here, 38/55 diseases were identified as sequelae. Notably, EBA patients showed an increased risk for metabolic and cardiovascular disease, and thrombosis. Furthermore, the risk for CIDs, especially lupus erythematosus and lichen planus, was elevated. These insights into risk factors and sequelae of EBA are not only of clinical relevance, e.g., optimizing cardiovascular disease risk, but in addition, point to shared pathogenetic pathways between EBA and other inflammatory diseases.

Lymphocyte-predominant lesional inflammatory infiltrates of the skin are associated with mucosal-dominant phenotype in pemphigus

INTRODUCTION

Pemphigus is a potentially life-threatening autoimmune blistering disease. To date, studies assessing the association of histopathology with clinical phenotype are lacking. We sought to evaluate the main histopathologic findings and, also, the potential links between cutaneous inflammatory infiltrates and clinical characteristics in pemphigus.

METHODS

We conducted a retrospective cohort study in patients diagnosed with pemphigus vulgaris (PV) and pemphigus foliaceus (PF) in a referral center for autoimmune blistering diseases.

RESULTS

A total of 124 patients were included in the study (97 had PV and 27 had PF). On biopsy specimens, PV was more frequently associated with the "row of tombstones" feature (36.1% vs. 11.1%, p = 0.013), and PF was associated with acanthosis (44.4% vs. 23.7%, p = 0.034). Acantholysis was found in the upper half of the epidermis in PF (96.3% vs. 5.15%, p < 0.001), as opposed to the lower half in PV (75.2% vs. 0%, p = 0.002). Patients with lymphocyte-predominant inflammatory infiltrates in lesional skin specimens presented with a higher frequency of the mucosal-dominant phenotype (25.5% vs. 9.1%, p = 0.014), higher-density cellular infiltrate (100% vs. 41.6%, p < 0.001), and more frequent acantholytic cells (42.6% vs. 23.4%, p = 0.025). Neutrophil-predominant infiltrates in specimens from lesional skin were linked to a milder disease based on median Pemphigus Disease Area Index (38.9% vs. 13.2%, p = 0.036) and Autoimmune Bullous Skin Disorder Intensity Score (20.2 vs. 36.3, p = 0.019), while eosinophil-predominant inflammatory infiltrates were more often associated with eosinophilic spongiosis (100% vs. 23.1%, p = 0.014).

CONCLUSIONS

Lymphocyte-predominant infiltrates in lesional skin specimens of pemphigus patients predict a mucosal-dominant phenotype, while neutrophil-predominant infiltrates are associated with a milder disease.

Direct Immunofluorescence of IgG on Formalin-Fixed Paraffin-Embedded Tissue by Heat-Induced Antigen Retrieval as a Sensitive Method for the Diagnosis of Pemphigus

Purpose

Direct immunofluorescence (DIF) on frozen sections (DIF-F) plays a key role in the identification and differential diagnosis of bullous dermatoses, which are a group of critical autoimmune diseases that include pemphigus, bullous pemphigoid (BP), and epidermolysis bullosa acquisita (EBA). However, this technique requires specialized laboratory equipment conditions, sample acquisition and sample preservation. In this study, the application value of DIF on paraffin-embedded tissue sections (DIF-P) detecting IgG using heat-induced antigen retrieval (HIAR) in the diagnosis of bullous dermatosis was explored.

Patients and Methods

Samples from 12 patients with pemphigus vulgaris (PV), 10 patients with pemphigus foliaceus (PF), 17 patients with BP, and 4 patients with EBA were retrospectively studied for DIF-P IgG detection. Formalin-fixed, paraffin-embedded tissue (FFPE) was used, and the antigen retrieval method used in the experiment was HIAR. All patients were diagnosed with the autoimmune bullous disease (AIBD) based on clinical presentation, histopathology, DIF-F, and enzyme-linked immunosorbent assay (ELISA).

Results

Intercellular staining for IgG in the epidermis was successful in paraffin-embedded tissue sections in 11 of 12 PV samples and in all 10 PF samples. IgG at the basement membrane zone (BMZ) was not detected by immunofluorescent staining in 17 BP samples and 4 EBA samples.

Conclusion

The detection of IgG by DIF-P using HIAR can be used for the diagnosis of pemphigus as an alternative method to DIF-F.

Levofloxacin-Associated Bullous Pemphigoid in a Hemodialysis Patient After Kidney Transplant Failure

BACKGROUND Patients with end-stage renal disease (ESRD) who require dialysis can develop a variety of skin conditions, such as pruritus, xerosis, skin infections, and autoimmune reactions. Bullous pemphigoid (BP) is an autoimmune bullous disorder with an increasing incidence. It can be caused by over 90 medications, but levofloxacin-induced BP in hemodialysis patients has not yet been reported. This report is of a 27-year-old woman with ESRD on hemodialysis who developed BP after levofloxacin treatment. CASE REPORT A 27-year-old woman with hemodialysis after kidney transplantation failure was started with levofloxacin for suspected urinary tract infection 1.5 months prior to admission. Her urinary tract infection symptoms were improved after 3 weeks of levofloxacin treatment, but a serious rash developed, presenting with progressive bullous throughout the body and facial involvement. A thorough workup showed a remarkably elevated hemidesmosomal antigen, BP180 (116 RU/mL), and cutaneous indirect immunofluorescence on human salt-split skin substrate was positive for serum basement membrane zone IgG with an epidermal pattern. Skin biopsy direct immunofluorescence staining showed continuous linear C3 deposition along the basement membrane zone. Prednisone 60 mg daily was started with a taper schedule. She no longer had new skin rash during a follow-up of over 3 months. CONCLUSIONS To the best of our knowledge, this is the first case of levofloxacin-induced BP in a patient undergoing hemodialysis. This report highlights the importance of recognizing skin reactions associated with ESRD in dialysis patients, the correct diagnosis by biopsy and histopathology, and the correct and timely management.

Staphylococcal Scalded Skin Syndrome in Neonates: Case Series and Overview of Outbreaks

Skin and soft tissue infections caused by Staphylococcus aureus (S. aureus) cover a wide spectrum of diseases in neonates, including staphylococcal scalded skin syndrome (SSSS). We describe a representative case of SSSS in neonatal twins, which despite recurrence showed a mild clinical disease course. This case was part of a small outbreak on a neonatal intensive care unit and therefore exemplifies the existence of neonatal outbreaks with skin and soft tissue infections by S. aureus. Diagnosis is generally based on the clinical picture and response to antibiotics, but can be aided by histology and cultures. Sequence-based molecular techniques are available to evaluate typing and virulence of S. aureus in outbreak or surveillance settings. The pillars of treatment are antibiotics and supportive care. Methicillin resistance remains a topic of concern, especially in outbreak settings. Our overview of numerous outbreaks of neonatal S. aureus skin infections underlines the importance of outbreak management strategies, including screening to identify the source of the outbreak, and limiting exposure through hygienic measures and establishment of physical boundaries.

Novel PGM3 mutation in two siblings with combined immunodeficiency and childhood bullous pemphigoid: a case report and review of the literature

BACKGROUND

Bullous pemphigoid is the most common autoimmune subepidermal blistering disorder with a low incidence in childhood. Combined immunodeficiencies (CIDs) are a group of monogenic inborn errors of immunity (IEIs) characterized by T- and B-cell dysfunction leading to recurrent infections, lymphoproliferation, predisposition to malignancy, and autoimmunity. Here, we report two Afghan siblings with a diagnosis of CID and extremely rare manifestation of diffuse bullous pemphigoid skin lesions.

CASE PRESENTATION

The older sibling (patient 1) was a 32-month-old male with facial dysmorphism, protracted diarrhea, failure to thrive, recurrent oral candidiasis, recurrent otitis media with tympanic membrane perforation, who had been previously diagnosed with CID. While he was under treatment with intravenous immunoglobulin (IVIg), he developed extensive blistering lesions, which were diagnosed as childhood bullous pemphigoid. Methylprednisolone and azathioprine were added to the regimen, which resulted in a remarkable improvement of the skin lesions and also the feeding condition. However,2 weeks later, he was re-admitted to the intensive care unit (ICU) and eventually died due to fulminant sepsis. Later, his 12-month-old sister (patient 2) with similar facial dysmorphism and a history of developmental delay, food allergy, recurrent oral candidiasis, and respiratory tract infections also developed blistering skin lesions. She was under treatment for occasional eczematous lesions, and had been receiving IVIg for 3 months due to low levels of immunoglobulins. Further immunologic workup showed an underlying CID and thus treatment with IVIg continued, gradually improving her clinical condition. The genetic study of both siblings revealed a novel homozygous mutation in exon 7 of the PGM3 gene, c.845 T > C (p.Val282Ala).

CONCLUSIONS

Dermatologic disorders may be the presenting sign in patients with CID and mutated PGM3. This case report further extends the spectrum of skin manifestations that could be observed in PGM3 deficiency and emphasizes the importance of considering CIDs during the assessment of skin disorders, particularly if they are extensive, recurrent, refractory to treatment, and/or associated with other signs of IEIs.

The basement membrane in epidermal polarity, stemness, and regeneration

The epidermis is a specialized epithelium that constitutes the outermost layer of the skin, and it provides a protective barrier against environmental assaults. Primarily consisting of multilayered keratinocytes, the epidermis is continuously renewed by proliferation of stem cells and the differentiation of their progeny, which undergo terminal differentiation as they leave the basal layer and move upward toward the surface, where they die and slough off. Basal keratinocytes rest on a basement membrane at the dermal-epidermal junction that is composed of specific extracellular matrix proteins organized into interactive and mechanically supportive networks. Firm attachment of basal keratinocytes, and their dynamic regulation via focal adhesions and hemidesmosomes, is essential for maintaining major skin processes, such as self-renewal, barrier function, and resistance to physical and chemical stresses. The adhesive integrin receptors expressed by epidermal cells serve structural, signaling, and mechanosensory roles that are critical for epidermal cell anchorage and tissue homeostasis. More specifically, the basement membrane components play key roles in preserving the stem cell pool, and establishing cell polarity cues enabling asymmetric cell divisions, which result in the transition from a proliferative basal cell layer to suprabasal cells committed to terminal differentiation. Finally, through a well-regulated sequence of synthesis and remodeling, the components of the dermal-epidermal junction play an essential role in regeneration of the epidermis during skin healing. Here too, they provide biological and mechanical signals that are essential to the restoration of barrier function.

Annular lichenoid diseases

Annular lichenoid diseases encompass a diverse range of pathologies that present as circular, raised, or flat lesions that may vary in size and number. Examples include annular lichenoid dermatitis of youth, annular lichen planus, erythema dyschromicum perstans, erythema multiforme, fixed drug eruption, lichen sclerosus, neonatal lupus, porokeratosis, subacute cutaneous lupus erythematosus, and lichenoid syphilis. Clinical morphology and histopathology can differentiate these entities.

Western blotting: a powerful staple in scientific and biomedical research

Western blotting (WB), also known as immunoblotting, is a well-known molecular biology method that biologists often use to investigate many features of the protein, ranging from basic protein analysis to disease detection. WB is simple, unique, rapid, widely used routine tool with easy interpretation and definite results. It is being used in various fields of science, research and development, diagnostic labs and hospitals. The principle of WB is to accomplish the separation of proteins based on molecular weight and charge. This review addresses in detail the individual steps involved in the WB technique, its troubleshooting, internal loading controls, total protein staining and its diverse applications in scientific research and clinical settings, along with its future perspectives.

Current and Innovated Managements for Autoimmune Bullous Skin Disorders: An Overview

Autoimmune bullous skin disorders are a group of disorders characterized by the formation of numerous blisters and erosions on the skin and/or the mucosal membrane, arising from autoantibodies against the intercellular adhesion molecules and the structural proteins. They can be classified into intraepithelial or subepithelial autoimmune bullous dermatoses based on the location of the targeted antigens. These dermatoses are extremely debilitating and fatal in certain cases, depending on the degree of cutaneous and mucosal involvement. Effective treatments should be implemented promptly. Glucocorticoids serve as the first-line approach due to their rapid onset of therapeutic effects and remission of the acute phase. Nonetheless, long-term applications may lead to major adverse effects that outweigh the benefits. Hence, other adjuvant therapies are mandatory to minimize the potential harm and ameliorate the quality of life. Herein, we summarize the current therapeutic strategies and introduce promising therapies for intractable autoimmune bullous diseases.

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.

Gestational Pemphigoid Presenting in the Second Trimester of Pregnancy: A Rare Finding

Gestational pemphigoid (GP) is a rare autoimmune blistering disorder, occurring in 1 in 60,000 pregnancies. It occurs in the second or third trimester of pregnancy and is characterized by autoantibodies against hemidesmosomal proteins. A variety of dermatological conditions are associated with pregnancy; among these skin diseases, gestational pemphigoid is very rare. The purpose of this report is to highlight the specific findings of this rare disease to enable clinicians to take prompt intervention in treating this condition. A 23-year-old multigravida, with no known comorbidities, presented to us at 18 weeks of gestation with complaints of intensely pruritic tense blisters all over the body, sparing the scalp, palms, and soles. The diagnosis was confirmed by skin biopsy for histopathology, after which the patient was started on prednisolone, which was then gradually tapered to an appropriate maintenance dose and then discontinued as the patient did not report any new lesions after delivery. Gestational pemphigoid can recur in subsequent pregnancies with more severe lesions. However, this was the first time the patient presented with this condition in her third pregnancy. Proper management of this disease requires close monitoring and appropriate drug therapy to reduce maternal and neonatal morbidity.

Challenges and pitfalls between lichen planus pemphigoides and bullous lichen planus

Lichen planus pemphigoides (LPP) and bullous lichen planus (BLP) are rare dermatoses, which are characterised by blisters and lichenoid lesions. Their clinical presentation is heterogenous, displaying overlapping features or mimicking other dermatological diseases. Therefore, diagnosis can often be challenging, requiring a thorough dermatological examination along with distinctive histological and immunopathological characteristics. Lichenoid degeneration of the basal epidermis exposes various antigens of the dermal-epidermal junction in LPP, resulting in the breakdown of immune tolerance, hence, the production of autoantibodies against type XVII collagen. Conversely, no pathogenic autoantibodies are detected in BLP. However, some cases of mucosal lichen planus might display immunopathological features suggestive of autoimmune blistering diseases. Therefore, a better understanding of the pathophysiology of these two distinct dermatoses is imperative. The aim of this review was to provide a summary of the current knowledge on the clinical hallmarks, diagnosis and available therapeutic options in LPP and BLP.

When Bullous Pemphigoid Is Not Bullous Pemphigoid: The Importance of Going Beyond Direct Immunofluorescence

Bullous pemphigoid (BP) is the most common autoimmune bullous disease, but rarer forms of pemphigoid may appear identical to BP on routine histopathology and direct immunofluorescence (DIF). Here, we present the case of a 60-year-old man, who was initially thought to have BP, with supportive findings on routine histopathology and DIF. However, prominent oral involvement and cutaneous lesions refractory to conventional treatment suggested an alternate diagnosis. Further workup was performed, including indirect immunofluorescence (IIF) on salt-split skin, which showed binding of antibodies to the dermal floor rather than to the blister roof, and enzyme-linked immunosorbent assay for pemphigus and pemphigoid antibodies. With these additional tests, we concluded that the patient does not have BP but rather anti-p200 pemphigoid, anti-p105 pemphigoid, or a yet undiscovered form of pemphigoid. We reached a presumptive diagnosis of anti-p200 pemphigoid, as it is the most common pemphigoid with serum antibodies to the dermal floor of human salt-split skin by IIF. This case demonstrates that suspicion for other autoimmune bullous diseases in cases of treatment-refractory and clinically aberrant BP is essential. A limited workup may lead to a missed diagnosis and ultimately less efficient disease management.

Assessment of Clinical and Laboratory Use of the Cutaneous Direct Immunofluorescence Assay

Importance

Dermatologists submit direct immunofluorescence (DIF) biopsies on a daily basis, using an assay detecting immunoreactant deposition with a panel that has traditionally comprised immunoglobulin (Ig) G, IgA, IgM, C3, and fibrin, with or without albumin antibodies.

Objectives

To evaluate and compare the frequency of immunoreactants in DIF biopsies submitted over an 8-year period and assess use by dermatologists based on clinical impression.

Design, Setting, and Participants

A quality improvement study was conducted in a community outreach reference laboratory associated with a large academic medical center. Results of 2050 consecutive DIF skin biopsies submitted to the laboratory between April 1, 2012, and June 12, 2020, were analyzed by final pathologic diagnosis and antibody subtype positivity, in comparison with clinical impression. Biopsies in which the submitting physician had not performed the biopsy were excluded.

Main Outcomes and Measures

Histopathologic findings and the results of DIF biopsies using the standard 6-antibody panel were evaluated in correlation with the submitted clinical diagnosis to assess immunoreactivity of the assay.

Results

Of 2050 DIF biopsies submitted, 367 (17.9%) were positive; IgG, IgA, and C3 alone identified all primary immunobullous disease cases (pemphigoid, pemphigus, linear IgA, and dermatitis herpetiformis), and IgA, C3, and fibrin antibodies alone identified all vasculitis cases. A panel of IgG, IgA, IgM, and fibrin identified all cases of lupus erythematosus. DIF results were positive in less than half of cases of hematoxylin and eosin biopsy-confirmed lupus erythematosus (23 of 47 [49%]). A total of 247 biopsies were submitted for clinical diagnoses not optimally supported on DIF: lichen planus, porphyria, and connective tissue disease.

Conclusions and Relevance

The findings of this study suggest that there is a knowledge gap among dermatologists relating to the opportunity for high-value, cost-conscious use of DIF. The practice of reflexive antibody testing using a 6-antibody panel for all DIF biopsies is likely unnecessary. DIF protocols tailored to the clinical diagnosis may enhance cost-effectiveness without loss of test sensitivity or specificity.

Targeted Therapies in Autoimmune Skin Diseases

Unlike the established anti-inflammatory drugs with a broad range, new-targeted therapeutic approaches have emerged in the management of autoimmune skin diseases to increase efficacy and decrease adverse reactions on the basis of an improved molecular understanding of pathogenesis. Most inflammatory dermatoses are driven by misled immune responses physiologically directed at exogenous pathogens, that is, type 1 immunity against viral pathogens, type 2 immunity against parasites, and type 3 immunity against fungi and bacteria. Pathogenic hallmarks of these major immune reaction patterns are characterized within this article, and a comprehensive overview of current clinical trials evaluating targeted therapeutics for respective dermatoses is outlined.

Immunoglobulin and Complement Immunohistochemistry on Paraffin Sections in Autoimmune Bullous Diseases: A Systematic Review and Meta-analysis

ABSTRACT

Immunohistochemistry (IHC) on formalin-fixed, paraffin-embedded tissue has been proposed as a potential tool in the diagnosis of autoimmune bullous diseases (AIBDs) in lieu of standard direct immunofluorescence (DIF) microscopy. To comprehensively determine the diagnostic accuracy of immunoglobulin and complement IHC for diagnosis of AIBDs, we conducted a systematic review and multivariate Bayesian model-based meta-analysis of the literature. Quality and heterogeneity assessment of studies was performed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) checklist and the I2 index, respectively. Electronic searches using PubMed from April 1964 to July 2020 identified 14 articles meeting predetermined inclusion and exclusion criteria. Median sensitivities with 95% credible intervals in pemphigus and pemphigoid were 0.24 (0.01-0.89) and 0.22 (0.02-0.77) with immunoglobulin G (IgG), 0.77 (0.39-0.95) and 0.25 (0.02-0.85) with IgG4, 0.11 (0.02-0.32) and 0.86 (0.56-0.98) with C3d, and 0.84 (0.56-0.97) and 0.75 (0.37-0.94) with C4d, respectively. Specificities were 1.00 (0.00-1.00) with IgG, 0.98 (0.89-1.00) with IgG4, 0.99 (0.97-1.00) with C3d, and 0.99 (0.97-1.00) with C4d. The risk of bias and heterogeneity among studies was a serious problem, decreasing the level of evidence. Our work suggests that, in selected cases, paraffin-based IHC may be a helpful procedure to screen for AIBDs, especially when specialized laboratories and/or biopsy specimens for DIF do not exist. Nevertheless, more studies with a refined quality design are needed to explore the true usefulness of this diagnostic method in AIBDs.

Detection of circulating anti-skin antibodies by indirect immunofluorescence and by ELISA: a comparative systematic review and meta-analysis

Background Both enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence (IIF) are available for the diagnosis of autoimmune bullous diseases (AIBD). Many studies have reported on the performance of ELISAs and concluded that ELISAs could replace IIF. This study compares the diagnostic accuracy of ELISA and IIF for the detection of autoantibodies to desmoglein 1 (DSG1), desmoglein 3 (DSG3), bullous pemphigoid antigen 2 (BP180) and bullous pemphigoid antigen 1 (BP230) to support the diagnosis of pemphigus vulgaris (PV), pemphigus foliaceus (PF) and bullous pemphigoid (BP). Methods A literature search was performed in the PubMed database. The meta-analysis was performed using summary values and a bivariate random effect model. Results The five included studies on PV did not demonstrate significant differences between IIF and DSG3-ELISA (sensitivity 82.3% vs. 81.6%, p = 0.9284; specificity 95.6% vs. 93.9%, p = 0.5318; diagnostic odds ratio [DOR] 101.60 vs. 67.760, p = 0.6206). The three included studies on PF did not demonstrate significant differences between IIF and DSG1-ELISA (sensitivity 80.6% vs. 83.1%, p = 0.8501; specificity 97.5% vs. 93.9%, p = 0.3614; DOR 160.72 vs. 75.615, p = 0.5381). The eight included studies on BP showed that BP230-ELISA differed significantly from both IIF on monkey esophagus (MO) and BP180-ELISA with regard to DOR (11.384 vs. 68.349, p = 0.0008; 11.384 vs. 41.699, p = 0.0125, respectively) Conclusions Our meta-analysis shows that ELISA performs as well as IIF for diagnosing PV, PF and BP.

Immunological features and factors associated with mucocutaneous bullous pemphigoid - a retrospective cohort study

BACKGROUND AND OBJECTIVES

The features of bullous pemphigoid (BP) patients presenting with mucosal lesions are not established. We aimed to elucidate the clinical and immunological features of BP patients with mucosal involvement, and to identify factors associated with mucosal lesions.

PATIENTS AND METHODS

A retrospective study encompassing all consecutive patients diagnosed with BP throughout the years 2009-2019 in a tertiary referral center.

RESULTS

The study encompassed 273 patients with BP, of whom 31 (11.4 %) presented with mucosal lesions. The oral mucosa was the most frequently affected mucosal surface (71.0 %), followed by the genital (25.8 %) and the nasal (22.6 %) mucosae. Relative to other patients with BP, patients with mucosal involvement had a more prominent palmoplantar involvement (67.7 % vs. 37.2 %; P = 0.001); lower seropositivity rate (18.2 % vs. 54.2 %; P = 0.027) and lower levels (29.3 ± 64.5 vs. 129.5 ± 304.4 U/ml; P = 0.016) of anti-BP230 autoantibodies; and decreased peripheral eosinophil counts (760.0 ± 638.6 vs. 1296.3 ± 1013.7; P < 0.001). Absence of anti-BP230 autoantibodies (OR, 5.32; 95 % CI, 1.07-26.32; P = 0.026) and lack of peripheral eosinophilia (OR, 4.31; 95 % CI, 1.14-16.39; P = 0.021) were associated with the presence of mucosal involvement in BP.

CONCLUSIONS

Mucosal involvement is present in a notable subgroup of patients with BP and is associated with the absence of both anti-BP230 antibodies and peripheral eosinophilia.

The impact of lesional inflammatory cellular infiltrate on the phenotype of bullous pemphigoid

BACKGROUND

The influence of cutaneous cellular infiltration on the phenotype of bullous pemphigoid (BP) remains to be established.

OBJECTIVES

To evaluate the main histopathological characteristics of patients with BP and to assess the association between the composition of lesional inflammatory infiltrate and the various clinical, immunological and immunopathological aspects of the disease.

METHODS

Retrospective study encompassing patients diagnosed with BP throughout the years 2009-2020 in a specialized tertiary referral centre.

RESULTS

The study encompassed 136 patients with BP, of whom 27 (19.9%) demonstrated a cell-poor inflammatory infiltrate in lesional skin specimens. Overall, 78 (57.4%), 71 (52.2%) and 5 (3.7%) specimens were found to include eosinophil-predominant, lymphocyte-predominant and neutrophil-predominant inflammatory infiltrates, respectively. Relative to the remaining patients with BP, those with an eosinophil-predominant inflammatory infiltrate had higher (90.8% vs. 77.2%; P = 0.030) whilst those with a cell-poor inflammatory infiltrate lower (70.3% vs. 88.7%; P = 0.017) seropositivity of anti-BP180 NC16A IgG. The latter subgroup presented with higher prevalence of mucosal involvement (25.9% vs. 8.3%; P = 0.011) and a non-inflammatory clinical phenotype (50.0% vs. 17.1%; P = 0.041). Patients with lymphocyte-predominant inflammatory infiltrate manifested with higher severity BPDAI scores and a lower frequency of the non-inflammatory subtype (11.1% vs. 36.4%; P = 0.035), whilst those with a neutrophilic infiltrate presented with lower mean (SD) levels of anti-BP180 NC16A IgG [269.3 (227.6) vs. 722.7 (1499.6) U/mL; P = 0.003].

CONCLUSIONS

Eosinophil-predominance and high cellularity in the lesional inflammatory infiltrate of BP skin are associated with increased seropositivity of anti-BP180 NC16A IgG. Lymphocyte-predominant infiltrates predict a more severe phenotype, pointing towards a pathogenic role of autoreactive lymphocytes.

S2k guidelines (consensus statement) for diagnosis and therapy of dermatitis herpetiformis initiated by the European Academy of Dermatology and Venereology (EADV)

INTRODUCTION

Dermatitis herpetiformis (DH) is a chronic, pruritic, gluten-induced skin disorder characterized by subepidermal granular IgA deposition and a variable degree of enteropathy identical to that seen in coeliac disease. So far, there has been no European consensus about the management of DH.

METHODS

The guidelines were created by small subgroups of a guideline committee consisting of 26 specialists from various medical fields and one patients' representative. The members of the committee then discussed the guidelines and voted for the final version at two consensus meetings. The guidelines were developed under the support of the European Academy of Dermatology and Venereology (EADV) and in collaboration with the European Dermatology Forum (EDF).

RESULTS

The guidelines summarize evidence-based and expert-based recommendations (S2 level) for the management of DH (see Appendix).

CONCLUSION

These guidelines will improve the quality of management of DH and support dermatologists in their diagnostic and therapeutic decisions.

Simultaneous immunofluorescence and histology in pemphigus vulgaris using ex vivo confocal laser scanning microscopy

Ex vivo confocal laser scanning microscopy (ex vivo CLSM) provides rapid, high-resolution imaging and immunofluorescence examinations of the excised tissues. We aimed to evaluate the applicability of ex vivo CLSM in histomorphological and direct immunofluorescence (DIF) examination of pemphigus vulgaris (PV). 20 PV sections were stained with fluorescent-labeled anti-IgG and anti-C3 using various dilutions and incubation periods. Subsequently, the determined ideal staining protocol was applied on 20 additional PV and 20 control sections. Ex vivo CLSM identified intraepidermal blisters and acantholytic cells in 80% and 60% of PV patients, respectively. The sensitivity of ex vivo CLSM in detecting intraepidermal fluorescence was 90% both with IgG and C3. The specificity of staining for IgG and C3 was 70% and 90%, respectively. Histomorphological and immunofluorescence features of PV could be detected within the same ex vivo CSLM session showing a comparable performance to conventional histopathology and DIF microscopy.

Beyond the skin: disease parameters in pemphigus

Pemphigus represents a group of rare autoimmune bullous diseases that affect the skin and mucous membranes. This group has a chronic course leading to high morbidity and mortality. Because of the painful chronic-recurring blisters and/or erosions on skin and mucosa, pemphigus can impair quality of life (QOL). Therapeutic modalities, anxiety and depression can also have an additional negative impact in the QOL of the pemphigus patients. Since the nature and course of the pathology and the fact that pemphigus worsens the quality of life of affected patients, scoring systems to objectively evaluate the clinical activity of the disease and to correlate that with the QOL are needed. Nowadays the most used global scales to assess the clinical activity of pemphigus are the Autoimmune Bullous Skin Disorder Intensity Score (ABSIS), the Pemphigus Disease Area Index (PDAI) and the Pemphigus Visual Activity Scale (PVAS). To evaluate the patient's generic QOL the most used score is the Dermatology Life Quality Index (DLQI), but all the sponsered clinical trials in pemphigus are using ABQOL this rather than DLQI.

Current approaches to the diagnosis of autoimmune bullous dermatoses

A modern review of highly effective methods for the diagnosis of autoimmune bullous dermatoses are presented. The specificity of the production of autoantibodies underlying bullous dermatoses are described. Considering the severity of the disease and a significant deterioration in the quality of life of patients suffering from bullous dermatoses; the systematization of diagnostic criteria will help improve the prognosis and management of patients; and it will also help optimize work on the development of targeted drugs for the treatment of patients with this pathology.

A 62-year-old man with new-onset bullae

Cutaneous blisters and/or bullae can occur in autoimmune disorders, infections, genetic diseases, and drug hypersensitivity. We present the case of a 62-year-old man with two autoimmune conditions who was admitted for antibiotic treatment of a lower extremity infection and suddenly developed a bullous rash. His physical examination was significant for tense, bullous lesions that involved his chin, palms, and inner thighs. Narrowing the differential diagnosis for patients with blistering skin lesions is imperative for timely and appropriate management.