Pemphigus trigger factors: special focus on pemphigus vulgaris and pemphigus foliaceus

Focus on pemphigus treatment publications: A bibliometric and visual analysis (1992-2022)

Pemphigus is a chronic recurrent disease in dermatology. Although it is not very common, its treatment has been an increasing concern in recent years because it is difficult and long-lasting. At present, there are many papers on pemphigus treatment, and to better understand the research trends and research frontiers of pemphigus treatment, it is necessary to conduct a comprehensive systematic review and analysis. We combined bibliometric and visualization methods to analyze 1365 papers published in the Web of Science database from 1992 to 2022, including basic information about countries, institutions and authors, to gain a general understanding of the treatment of pemphigus. Among them, the United States is the country with the most output, Iran's Tehran University of Medical Sciences is the institution with the most published works, and Ahmed, A. Razzaque of Tufts University is the most influential scholar. In addition, we also learned about the research hotspots and frontiers of pemphigus treatment through a series of analyses on the frequency, clustering, keywords bursts and cited literature, and we briefly reviewed the highly cited literature. We found that the current research focuses in the study of pemphigus treatment are the types, pathogenesis, and treatment of pemphigus, including glucocorticoids, immunosuppressants and many other major treatment methods. Hailey-Hailey disease, genetic susceptibility, and traditional Chinese medicine are potential research hotspots. Rituximab is a research frontier. In conclusion, we hope to provide new research ideas for promoting the development of pemphigus treatment.

Restoring immune tolerance in pemphigus vulgaris

Intravenous immunoglobulin (IVIg), a preparation of polyclonal serum IgG pooled from numerous blood donors, has been used for nearly three decades and is proving to be an efficient treatment for many autoimmune blistering diseases, including pemphigus vulgaris (PV). Despite its widespread use and therapeutic success, its mechanisms of action are not completely understood. Some of its anti-inflammatory and immunomodulatory actions have been studied. In this study, the authors present a twenty-year follow-up of 21 patients with clinical and immunopathological confirmed PV, treated with IVIg as monotherapy, according to an established published protocol. IVIg therapy produced long-term sustained, clinical, serological, and immunopathological remission. For 20 y, these patients received no drugs and experienced no disease. This observation suggests that there was the establishment of immune balance or restoration of immune regulation in these PV patients. Twelve (57%) patients experienced no relapse during follow-up. Six (29%) patients experienced a relapse due to acute stress or post-coronavirus infection and/or vaccination. Reinstitution of IVIg resulted in prompt sustained recovery. Three (14.2%) patients, in clinical and serological remission, died due to unrelated causes. No severe adverse effects from IVIg were documented in all 21 patients. The simultaneous or sequential anti-inflammatory and immunomodulatory effects of IVIg may have influenced the long-term clinical remission observed. This study provides a human prototype to examine the pathophysiology of autoimmunity and a model to study immune regulation and mechanisms that can facilitate restoring immune tolerance.

Epidemiological and clinical study of cases of endemic pemphigus foliaceus and pemphigus vulgaris in a reference center in the state of Minas Gerais, Brazil

BACKGROUND

Pemphigus constitutes a group of autoimmune bullous diseases. A reduction in the incidence of endemic pemphigus foliaceus and an increase in pemphigus vulgaris has been described, but there are no studies in Minas Gerais that address the subject.

OBJECTIVE

To describe the epidemiological and clinical profile of patients with pemphigus treated at the Dermatology Service of a public University Hospital in the state of Minas Gerais, Brazil.

METHODS

An observational, descriptive, and cross-sectional study was carried out of cases of endemic pemphigus foliaceus and pemphigus vulgaris, for a period of six months. A questionnaire was filled out with epidemiological and clinical data on the disease.

RESULTS

A total of 122 patients were included in the study, 64 with endemic pemphigus foliaceus and 58 with pemphigus vulgaris. When comparing patients with endemic pemphigus foliaceus and those with pemphigus vulgaris, a statistical difference was observed between the median age of initial disease manifestation (p = 0.001), patient occupation (p = 0.010), area of residence (p = 0.000), forests (p = 0.000) and rivers/streams close to the dwelling (p = 0.001) and the number of systemic medications required to control the disease (p = 0.002). When comparing patients with endemic pemphigus foliaceus to those evaluated in a study carried out at the same service in 2008, there was a statistical difference in the area of residence (p = 0.030).

STUDY LIMITATIONS

The assessed population comes from a tertiary care service that is not a reference for the entire state.

CONCLUSIONS

Patients with endemic pemphigus foliaceus and pemphigus vulgaris maintain statistically significant differences regarding their main variables in the literature, such as age and area of residence. Historically, there has been a reduction in cases of endemic pemphigus foliaceus and an increase in cases of pemphigus vulgaris in this population.

Pregnancy in pemphigus vulgaris: A systematic review

PROBLEM

Pemphigus vulgaris may worsen during pregnancy, leading to both maternal and fetal complications. The relationship between pemphigus vulgaris and pregnancy remains unclear, and the outcomes and treatments of pemphigus vulgaris during pregnancy have not been extensively discussed.

METHOD OF STUDY

This article systematically reviews the literature, focusing on the relationship between pemphigus vulgaris and pregnancy. We conducted comprehensive searches in PubMed, Embase, Cochrane Library, and Web of Science databases, identifying 42 studies reporting the disease course, pregnancy outcomes, and management of both pregnancy and pemphigus vulgaris.

RESULTS

A total of 57 cases were included in the analysis, categorized into three distinct forms: pemphigus vulgaris onset before pregnancy (n = 33), onset during pregnancy (n = 20), and onset during the postpartum period (n = 4). Fifty four cases reported treatment strategies, among them, 44 cases (81.5%) initially received systemic corticosteroid therapy during pregnancy. Out of these cases, 7 (15.9%) did not achieve successful remission and required alternative treatment approaches. In terms of pregnancy outcomes, 23 out of 62 neonates (37.1%) exhibited skin lesions or tested positive for anti-dsg IgG in their serum, while 16 neonates (25.8%) experienced other complications.

CONCLUSIONS

These findings highlight the importance of effectively managing pemphigus vulgaris during pregnancy to ensure optimal outcomes.

Pemphigus: trigger and predisposing factors

Pemphigus is a life-threatening autoimmune blistering disease affecting skin and mucous membranes. Despite its etiopathogenesis remains largely unknown, several trigger and predisposing factors have been reported. Pemphigus is caused by autoantibodies that target desmoglein 1 and desmoglein 3, impacting desmosome function. However, circulating autoantibodies are often the consequence of a precipitating factor that occurs in predisposed individuals. This review aims to describe and discuss almost all trigger and predisposing factors reported as possible or probable cause of the disease. Among the reported trigger factors that may induce or exacerbate pemphigus, we have found of particular interest: drug intake (especially thiol- and phenol-containing compounds), vaccines, infections, as well as some reports about pregnancy, radiations, emotional stress, pesticides and physical trauma. Moreover, we discuss the possible role of food intake in pemphigus onset and particular attention is given to dietary factors containing thiol, phenol and tannin compounds. A trigger factor is "the straw that breaks the camel's back," and often acts together with predisposing factors. Here we discuss how pemphigus onset may be influenced by genetic susceptibility and comorbidities like thyroid diseases, malignancies and other autoimmune disorders. To identify other hitherto unknown trigger and predisposing factors, well designed prospective studies are needed. In this context, future research should explore their connection with the aim to advance our understanding of pemphigus pathogenesis.

Association of alternative healthy eating index and severity of pemphigus vulgaris: A cross-sectional study

BACKGROUND

Evidence on the association between following healthy eating and the severity of pemphigus vulgaris (PV) is scarce. Therefore, the aim of this cross-sectional study aimed to investigate the relationship between adherence to the alternative healthy eating index (AHEI) and the severity of Pemphigus vulgaris disease in adults.

METHODS

In this hospital-based cross-sectional study, a total of 138 pemphigus vulgaris cases were studied, of which 108 had pemphigus disease area index (PDAI) ≤15, and 30 had PDAI>15. Dietary intakes were assessed using a valid 168-item food frequency questionnaire (FFQ). To calculate the AHEI, the data received from the diet were used. The subjects of this index received a score of 1-10. The final AHEI was calculated by summing the component scores.

RESULTS

After adjusting for age and sex, we found that individuals with the highest AHEI score were 72% less likely to have increased PV severity compared with those with the lowest score (OR: 0.28; 95% CI: 0.08-0.92, P trend = 0.020). Further control for another potential confounder, intake energy, made the association stronger (OR: 0.24; 95% CI: 0.06-0.88, P trend = 0.017). Also, after controlling the body mass index (BMI) confounding factor, it maintained its strong relationship (OR: 0.24; 95% CI: 0.06-0.88, P trend = 0.016).

CONCLUSION

The evidence of our study shows that following the healthy eating index is associated with a reduction in the severity of pemphigus vulgaris. Prospective cohort studies are needed to confirm these findings.

Potential correlation of oral flora with pemphigus vulgaris - A case control study

Background/purpose

Oral flora is related to various immune-related diseases. Herein we explored the characteristics of oral flora in patients with pemphigus vulgaris (PV) and analyzed the correlation between oral flora and PV.

Materials and methods

Twenty-two untreated patients with PV and 12 healthy controls (HC) were included in this case-control study. The characteristics of salivary microbiome were assessed by high-throughput sequencing using the 16S rRNA Illumina MiSeq approach, and differences between the PV and HC groups were determined. The Kyoto Encyclopedia of Genes and Genomes (KEGG) database was applied to screen key metabolic pathways and preliminarily explore potential mechanisms underlying PV occurrence and development.

Results

The abundance of oral flora in the PV group was significantly lower than that in the HC group, and there were characteristic changes. The relative abundance of Prevotella and Agrobacterium in the PV group was significantly higher than that in the HC group (P < 0.05) and that of Neisseria, Lautropia, and Fusobacterium was significantly lower (P < 0.05). There was a linear correlation between Prevotella and serum Dsg3 level in PV. KEGG pathway analyses indicated significant differences in nine metabolic pathways between the PV and HC groups (P < 0.05), namely carbohydrate metabolism, digestive system, neurodegenerative disease, glycan biosynthesis and metabolism, drug resistance: antimicrobial, infectious disease: viral, circulatory system, excretory system, and nervous system.

Conclusion

The oral flora of patients with PV presented characteristic changes, and several metabolic pathways were affected, including N-glycan biosynthesis and metabolism. Prevotella spp. appear to require the most attention in PV. We believe that oral flora dysbacteriosis contributes to PV occurrence and development.

Autoimmune bullous disorder flares following severe acute respiratory syndrome coronavirus 2 vaccination: a case series

BACKGROUND

Autoimmune bullous disorders develop due to autoantibodies targeting intercellular adhesion proteins of hemidesmosomes and desmosomes and may be triggered by viral infections and vaccines. Recent reports suggest that the coronavirus disease 2019 vaccination may trigger flares or exacerbations of preexisting autoimmune diseases, including new onset autoimmune bullous disorders. There are less data on whether vaccination against severe acute respiratory syndrome coronavirus 2 may also exacerbate preexisting autoimmune bullous disorders.

CASE PRESENTATION

Here we present three cases, two white males (ages 69 years and 88 years) with bullous pemphigoid and one white 50-year-old female with pemphigus foliaceus, wherein all individuals developed minor, tractable flares of their preexisting autoimmune bullous disorders after receiving the coronavirus disease 2019 vaccination, which were readily treatable with topical or low-dose systemic corticosteroids.

CONCLUSIONS

Dermatologists managing patients with autoimmune bullous disorders should be cognizant of the uncommon potential for flares of the disorder following vaccination for severe acute respiratory syndrome coronavirus 2. Flares of bullous pemphigoid and pemphigus foliaceus following vaccination for severe acute respiratory syndrome coronavirus 2 in these cases were mild and tractable.

Environmental factors in autoimmune bullous diseases with a focus on seasonality: new insights

Autoimmune bullous diseases are a heterogeneous group of rare conditions clinically characterized by the presence of blisters and/or erosions on the skin and the mucous membranes. Practically, they can be divided into two large groups: the pemphigoid group and the pemphigus group, depending on the depth of the autoimmune process on the skin. A family history of autoimmune diseases can often be found, demonstrating that genetic predisposition is crucial for their development. Moreover, numerous environmental risk factors, such as solar radiation, drugs, and infections, are known. This study aimed to evaluate how seasonality can affect the trend of bullous pemphigoid and pemphigus vulgaris, especially considering the number of hospitalizations recorded over the course of individual months. The total number of hospitalizations in the twelve months of the year was evaluated. Moreover, blood chemistry assay and, for some patients, enzyme-linked immunosorbent assay were executed to evaluate antibodies. Regarding the severity of the disease, the bullous pemphigoid area index and the pemphigus disease area index score systems were used. Results showed a complex interplay between environmental factors such as seasons and autoimmune conditions.

Rare Cutaneous Side Effects of Imiquimod: A Review on Its Mechanisms, Diagnosis, and Management

As an immune-response modifier, imiquimod can bind to Toll-like receptors on immune cells and enhance innate and adaptive immune responses, exerting potential antitumor and antiviral effects, which led to its approval by the US Food and Drug Administration for the treatment of actinic keratosis, superficial basal cell carcinomas, and anogenital warts, and to its off-label use in treating many other benign and malignant dermatoses. Although topical administration of imiquimod has been considered well tolerated, an increasing number of cutaneous and noncutaneous side effects are being reported as its clinical applications expand. This review primarily focuses on rare cutaneous side effects. To the best of our knowledge, this is the first article to summarize the mechanism, diagnosis, and management of rare cutaneous side effects of imiquimod, which may help to heighten awareness among physicians, especially dermatologists, about potential imiquimod-induced cutaneous side effects.

Measurement of pesticides in hair samples from pemphigus foliaceus and pemphigus vulgaris patients in Southeastern Brazil

BACKGROUND

Pesticides, mainly organophosphates (OP), have been related to increased risk of pemphigus vulgaris (PV) and pemphigus foliaceus (PF), nevertheless, their measurement has not been determined in pemphigus patients.

OBJECTIVE

To evaluate pesticide exposure and pesticide measurement, comparing PV, PF and control groups in Southeastern Brazil.

METHODS

Information about urban or rural residency and exposure to pesticides at the onset of pemphigus was assessed by questionnaire interview; hair samples from the scalp of PV, PF, and controls were tested for OP and organochlorines (OC) by gas-phase chromatography coupled to mass spectrometry.

RESULTS

The minority of PV (2 [7.1%] of 28) and PF (7 [18%] of 39), but none of the 48 controls, informed living in rural areas at the onset of pemphigus (p = 0.2853). PV (33.3%), PF (38.5%), and controls (20%) informed exposure to pesticides (p = 0.186). Twenty-one (14.8%) of 142 individuals tested positive for OP and/or OC: PV (2 [6.3%] of 32) and PF (11 [25.6%] of 43) had similar pesticides contamination as controls (8 [11.9%] of 67) (p = 0.4928; p = 0.0753, respectively), but PF presented higher contamination than PV (p = 0.034). PV did not present any positivity for OP. Three (7%) PF tested positive for both OP and OC. Some PF tested positive for three or four OP, mainly diazinon and dichlorvos.

STUDY LIMITATION

Lack of data for some controls.

CONCLUSION

Although the frequency of PV and PF patients exposed to pesticides was similar, pesticides were more frequently detected in hair samples from PF compared to PV. The cause-effect relationship still needs to be determined.

Autoimmune skin disorders and SARS-CoV-2 vaccination - a meta-analysis

BACKGROUND AND OBJECTIVES

The coronavirus SARS-CoV-2, which is the cause of COVID-19 disease in infected patients, has led to an ongoing worldwide pandemic. Although SARS-CoV-2 vaccination had a dramatic positive effect on the course of COVID-19, there has been increasing evidence of adverse effects after SARS-CoV-2 vaccination. This meta-analysis highlights the association between SARS-CoV-2 vaccination and de novo induction or aggravation of inflammatory and autoimmune skin diseases.

MATERIAL AND METHODS

A systematic meta-analysis of the literature on new onset or worsening of inflammatory and autoimmune diseases after SARS-CoV-2 vaccination was performed according to the PRISMA guidelines. The search strategy included following terms: "COVID-19/SARS-CoV-2 vaccine bullous pemphigoid/pemphigus vulgaris/systemic lupus erythematosus/dermatomyositis/lichen planus/leukocytoclastic vasculitis." Moreover, we describe representative cases from our dermatology department.

RESULTS

The database-search in MEDLINE identified 31 publications on bullous pemphigoid, 24 on pemphigus vulgaris, 65 on systemic lupus erythematosus, nine on dermatomyositis, 30 on lichen planus, and 37 on leukocytoclastic vasculitis until June 30th, 2022. Severity and response to treatment varied among the described cases.

CONCLUSIONS

Our meta-analysis highlights a link between SARS-CoV-2 vaccination and new onset or worsening of inflammatory and autoimmune skin diseases. Moreover, the extent of disease exacerbation has been exemplified by cases from our dermatological department.

Autoimmunerkrankungen der Haut und SARS-CoV-2-Impfung - eine Metaanalyse

Hintergrund und Ziele

Das Coronavirus SARS‐CoV‐2, welches bei infizierten Patienten die COVID‐19‐Erkrankung auslöst, führte zu einer weltweiten Pandemie. Obwohl die SARS‐CoV‐2‐Impfung einen stark positiven Einfluss auf den Verlauf von COVID‐19 hatte, mehren sich die Hinweise auf Nebenwirkungen nach der SARS‐CoV‐2‐Impfung. Diese Metaanalyse unterstreicht den Zusammenhang zwischen der SARS‐CoV‐2‐Impfung und der Neuentstehung oder Verschlechterung von entzündlichen und autoimmunen Hauterkrankungen.

Materialien und Methodik

Eine systematische Metaanalyse der Literatur über das Neuauftreten oder die Verschlechterung von entzündlichen und autoimmunen Hauterkrankungen nach der SARS‐CoV‐2‐Impfung wurde gemäß den PRISMA‐Richtlinien durchgeführt. Die Suchstrategie umfasste folgende Begriffe: „COVID‐19/SARS‐CoV‐2 vaccine bullous pemphigoid/pemphigus vulgaris/systemic lupus erythematosus/dermatomyositis/lichen planus/leukocytoclastic vasculitis“ Außerdem beschreiben wir repräsentative Fälle aus unserer dermatologischen Abteilung.

Ergebnisse

Die Datenbanksuche in MEDLINE ergab bis zum 30.06.2022 31 Veröffentlichungen über bullöses Pemphigoid, 24 über Pemphigus vulgaris, 65 über systemischen Lupus erythematodes, neun über Dermatomyositis, 30 über Lichen planus und 37 über leukozytoklastische Vaskulitis. Schweregrad und Ansprechen auf die Behandlung waren bei den beschriebenen Fällen unterschiedlich.

Schlussfolgerungen

Unsere Metaanalyse zeigt einen Zusammenhang zwischen der SARS‐CoV‐2‐Impfung und dem Neuauftreten oder der Verschlechterung von entzündlichen und autoimmunen Hauterkrankungen. Darüber hinaus wurde das Ausmaß der Krankheitsverschlechterung anhand von Fällen aus unserer dermatologischen Abteilung veranschaulicht.

Autoimmune bullous dermatoses in cancer patients treated by immunotherapy: a literature review and Italian multicentric experience

Cutaneous immune-related adverse events are frequently associated with immune checkpoint inhibitors (ICIs) administration in cancer patients. In fact, these monoclonal antibodies bind the cytotoxic T-lymphocyte antigen-4 and programmed cell death-1/ligand 1 leading to a non-specific activation of the immune system against both tumoral cells and self-antigens. The skin is the most frequently affected organ system appearing involved especially by inflammatory manifestations such as maculopapular, lichenoid, psoriatic, and eczematous eruptions. Although less common, ICI-induced autoimmune blistering diseases have also been reported, with an estimated overall incidence of less than 5%. Bullous pemphigoid-like eruption is the predominant phenotype, while lichen planus pemphigoides, pemphigus vulgaris, and mucous membrane pemphigoid have been described anecdotally. Overall, they have a wide range of clinical presentations and often overlap with each other leading to a delayed diagnosis. Achieving adequate control of skin toxicity in these cases often requires immunosuppressive systemic therapies and/or interruption of ICI treatment, presenting a therapeutic challenge in the context of cancer management. In this study, we present a case series from Italy based on a multicenter, retrospective, observational study, which included 45 patients treated with ICIs who developed ICI-induced bullous pemphigoid. In addition, we performed a comprehensive review to identify the cases reported in the literature on ICI-induced autoimmune bullous diseases. Several theories seeking their underlying pathogenesis have been reported and this work aims to better understand what is known so far on this issue.

Cutaneous Adverse Events After COVID-19 Vaccination

Purpose

The morphology and timing of cutaneous reactions after Coronavirus disease (COVID-19) vaccines have been well described; however, data on the rates and risk factors are limited. Therefore, this study aimed to measure the incidence of cutaneous adverse reactions (CARs) after COVID-19 vaccination in Thailand, describe the rash characteristics according to the doses or types of vaccine, and assess the risk factors for developing CARs.

Patients and Methods

This was a prospective observational study of adults who received COVID-19 vaccination and provided informed consent. Cutaneous diagnoses were made by expert dermatologists with supporting skin biopsies, as needed. Data were analyzed using descriptive statistics and logistic regression to examine the independent risk of developing a CAR.

Results

Between July 2021 and January 2022, 7505 participants were vaccinated. Vaccine-related CARs occurred in 92 patients with an overall risk of 1.2%. CARs occurred after the first (n=41), second (n=23), third (n=27), and fourth (n=1) doses. Among the 92, 75 (81%) developed CARs within 7 days and 61 (66%) resolved within 7 days. Urticaria, injection site reaction, and a delayed (≥ 3 days post vaccine) local reaction were the three most common CARs occurring in 59 cases (64%). In total, 51 (55%) patients received only symptomatic and supportive treatment. Underlying urticaria and psoriasis were the independent factors for developing a CAR: adjusted odd rations of 15.63 (6.02-40.57, p < 0.001) and 5.36 (1.57-18.36, p = 0.007), respectively. A total of 6/34 (17%) and 4/31 (12%) patients developed urticarial and psoriasis flare post vaccine. Our study found superficial perivascular and intraepidermal eosinophil infiltration, which may be unusual pathological findings in vaccine-induced pemphigus foliaceous.

Conclusion

CARs after COVID-19 vaccination had a low incidence and were mostly mild in severity and transient in nature. Underlying urticaria and psoriasis were risk factors for CAR development.

The critical importance of epigenetics in autoimmune-related skin diseases

Autoimmune-related skin diseases are a group of disorders with diverse etiology and pathophysiology involved in autoimmunity. Genetics and environmental factors may contribute to the development of these autoimmune disorders. Although the etiology and pathogenesis of these disorders are poorly understood, environmental variables that induce aberrant epigenetic regulations may provide some insights. Epigenetics is the study of heritable mechanisms that regulate gene expression without changing DNA sequences. The most important epigenetic mechanisms are DNA methylation, histone modification, and noncoding RNAs. In this review, we discuss the most recent findings regarding the function of epigenetic mechanisms in autoimmune-related skin disorders, including systemic lupus erythematosus, bullous skin diseases, psoriasis, and systemic sclerosis. These findings will expand our understanding and highlight the possible clinical applications of precision epigenetics approaches.

The multifactorial complexities of autoimmune development in Pemphigus vulgaris: Critical evaluation of the role of environmental and lifestyle "exposome" factors

Pemphigus vulgaris (PV) is a potentially life-threatening blistering disorder characterized by autoantibodies directed against cell-cell adhesion molecules that serves as an excellent model to study human autoimmune development. Numerous studies have identified specific Human Leukocyte Antigen (HLA) genes, in particular DRB1*0402 and DQB1*0503, that confer disease risk. Although HLA is required, it is not sufficient for the initiation of disease. As with all autoimmune diseases, the etio-pathogenesis of PV is complex, meaning it is multifactorial. Susceptibility is polygenic, and the search for non-HLA disease-linked genes continues. Moreover, twin studies across autoimmune conditions indicate that non-genetic environmental and lifestyle factors, which can be collectively grouped under the term "exposome", are also major contributors to disease development. The literature presents evidence for the potential role of multiple triggers such as medications, infections, stress, diet, immunizations, and sleep to influence the etiology, pathophysiology, and prognosis of PV. However, a clear understanding of the degree to which specific factors impact PV is lacking. In this investigation, we comprehensively review the environmental elements listed above and consider the strength of evidence for these factors. The overall goals of this work are to provide greater insights into the factors that influence disease susceptibility, disease development and disease course and ultimately help to better guide clinicians and inform patients in the management of PV.

[Trigger factors associated with bullous autoimmune dermatoses]

BACKGROUND

Blistering autoimmune dermatoses are a heterogeneous group of rare diseases. Pemphigus diseases are distinguished from pemphigoid diseases as well as dermatitis herpetiformis. In pemphigus diseases, cutaneous blistering is caused by an intraepidermal loss of adhesion between keratinocytes. In pemphigoid diseases, blister formation is due to a subepidermal loss of adhesion of keratinocytes from the basement membrane.

OBJECTIVES

This article reviews the most important trigger factors associated with bullous autoimmune dermatoses and discusses their role in their initial manifestation as well as exacerbation.

MATERIALS AND METHODS

A focused review of the literature including original articles, guidelines, reference works and previously published review articles was performed.

RESULTS

Vaccinations, viral infections, ultraviolet light (UV) exposure and radiation therapies are possible triggers of pemphigus vulgaris in predisposed patients. For the much rarer pemphigus foliaceus, UV exposure is of particular importance. Thiols and phenols are drugs that can induce pemphigus usually resembling pemphigus foliaceus clinically. Age is the most important risk factor of bullous pemphigoid. In addition, in bullous pemphigoid associations with dipeptidyl peptidase 4 inhibitors, programmed cell death protein‑1 or programmed death-ligand‑1 inhibitors as well as neurological diseases are particularly relevant. Severe mucosal damage, certain drugs and in particular cases neoplasms might play a role in mucous membrane pemphigoid.

CONCLUSION

Knowing possible trigger factors facilitates a timely diagnosis upon initial manifestation and supports the prevention of relapse of bullous autoimmune dermatoses.

New-onset pemphigus foliaceus following SARS-CoV-2 infection and unmasking multiple sclerosis: A case report

Development of pemphigus foliaceus (PF) following SARS‐CoV‐2 infection has only been reported in one patient who had received Bamlanivimab and thus might be considered as a drug‐induced case of PF. Here, we reported the first case of PF arising solely after COVID infection without taking any culprit drug.

COVID‐19 has led to many dermatologic conditions. Here, we reported the first case of pemphigus foliaceus arising solely after SARS‐Cov‐2 infection without taking any culprit drug.

Genetic Associations and Differential mRNA Expression Levels of Host Genes Suggest a Viral Trigger for Endemic Pemphigus Foliaceus

The long search for the environmental trigger of the endemic pemphigus foliaceus (EPF, fogo selvagem) has not yet resulted in any tangible findings. Here, we searched for genetic associations and the differential expression of host genes involved in early viral infections and innate antiviral defense. Genetic variants could alter the structure, expression sites, or levels of the gene products, impacting their functions. By analyzing 3063 variants of 166 candidate genes in 227 EPF patients and 194 controls, we found 12 variants within 11 genes associated with differential susceptibility (p < 0.005) to EPF. The products of genes TRIM5, TPCN2, EIF4E, EIF4E3, NUP37, NUP50, NUP88, TPR, USP15, IRF8, and JAK1 are involved in different mechanisms of viral control, for example, the regulation of viral entry into the host cell or recognition of viral nucleic acids and proteins. Only two of nine variants were also associated in an independent German cohort of sporadic PF (75 patients, 150 controls), aligning with our hypothesis that antiviral host genes play a major role in EPF due to a specific virus−human interaction in the endemic region. Moreover, CCL5, P4HB, and APOBEC3G mRNA levels were increased (p < 0.001) in CD4+ T lymphocytes of EPF patients. Because there is limited or no evidence that these genes are involved in autoimmunity, their crucial role in antiviral responses and the associations that we observed support the hypothesis of a viral trigger for EPF, presumably a still unnoticed flavivirus. This work opens new frontiers in searching for the trigger of EPF, with the potential to advance translational research that aims for disease prevention and treatment.

Development of Severe Pemphigus Vulgaris Following ChAdOx1 nCoV‐19 Vaccination and Review of Literature

Vaccines are indeed a boon for tackling the present COVID‐19 pandemic. In India, ChAdOx1 nCoV‐19 (Covishield) is the most commonly used vaccine in the government vaccination program for adults more than 18 years of age. It is a recombinant vaccine developed by Oxford‐Astra Zeneca and manufactured in India by Serum Institute of India (SSI). Here, we report a case of severe pemphigus vulgaris following the second dose of ChAdOx1 nCoV‐19 vaccination in an adult male. The patient developed septicemia during the course of hospital stay, and he was managed with systemic steroids, parenteral antibiotics, and intravenous immunoglobulins (IVIg) along with proper wound care. Patient started improving within 1 month of therapy. This case is being reported in view of the rarity of pemphigus vulgaris following ChAdOx1 nCoV‐19 vaccine.

Genetic variants affecting chemical mediated skin immunotoxicity

The skin is an immune-competent organ and this function may be impaired by exposure to chemicals, which may ultimately result in immune-mediated dermal disorders. Interindividual variability to chemical-induced skin immune reactions is associated with intrinsic individual characteristics and their genomes. In the last 30-40 years, several genes influencing susceptibility to skin immune reactions were identified. The aim of this review is to provide information regarding common genetic variations affecting skin immunotoxicity. The polymorphisms selected for this review are related to xenobiotic-metabolizing enzymes (CYPA1 and CYPB1 genes), antioxidant defense (GSTM1, GSTT1, and GSTP1 genes), aryl hydrocarbon receptor signaling pathway (AHR and ARNT genes), skin barrier function transepidermal water loss (FLG, CASP14, and SPINK5 genes), inflammation (TNF, IL10, IL6, IL18, IL31, and TSLP genes), major histocompatibility complex (MHC) and neuroendocrine system peptides (CALCA, TRPV1, ACE genes). These genes present variants associated with skin immune responses and diseases, as well as variants associated with protecting skin immune homeostasis following chemical exposure. The molecular and association studies focusing on these genetic variants may elucidate their functional consequences and contribution in the susceptibility to skin immunotoxicity. Providing information on how genetic variations affect the skin immune system may reduce uncertainties in estimating chemical hazards/risks for human health in the future.

Patient Quality of Life Improvement in Bullous Disease: A Review of Primary Literature and Considerations for the Clinician

Autoimmune and inherited bullous disorders are rare skin diseases that may have a profound negative impact on quality of life (QOL). Common symptoms include pain, pruritus, and scarring, and complications may result in the loss of the ability to perform daily tasks. Diagnosis may have a negative psychological impact, and ongoing management may require a significant allocation of time and resources by both patients and providers. To provide patient-centered care, consideration of these factors is of utmost importance for the dermatologist treating patients with bullous disorders. Herein, we present a review of the primary literature evaluating QOL in autoimmune and inherited bullous disorders, including pemphigus, pemphigoid, epidermolysis bullosa, and Hailey-Hailey disease.

A Case of Newly Developed Pemphigus Foliaceus and Possible Association with Alternative Bee-Venom Therapy

Bee-venom is composed of a variety of peptides, enzymes, and biogenic amines, and is demonstrated to have both antiinflammatory and immune-stimulatory effects in human body. Pemphigus foliaceus (PF) is a variant of pemphigus, which is a rare autoimmune bullous disease presenting with erythematous scaly crusted plaques. Although the exact pathogenesis was not identified, there have been three case reports of autoimmune disorders associated with bee-venom. In this case, a 64-year-old female was diagnosed with PF, which was developed after alternative bee-venom acupuncture therapy. We assumed that the bee-venom caused the diseases through a temporal relationship and its known immunostimulatory action. Herein, we suggest that physicians recognize the possibility of bee-venom stimulating the immune system and triggering various autoimmune diseases including pemphigus.

A Comparison of Diagnosed Skin Diseases between the Years with and without COVID-19 Pandemic

Background and Objectives: The COVID-19 pandemic has a considerable influence on public health, either directly or indirectly. We investigated outpatient skin disease diagnoses at the dermatology clinic to determine the effect of the COVID-19 pandemic on these patients. Materials and Methods: We conducted a retrospective study using the International Codes of Diseases data from the outpatient department of Dermatology clinic, Vajira hospital, Navamindradhiraj University, Bangkok, Thailand from January 2019 to June 2021. Results: A total of 20,915 patients with 34,116 skin diagnoses were included in the study. The average weekly dermatologic clinic visits remained unchanged between the years with and without COVID-19 pandemic. While the percentage of xerosis cutis, other skin infections (syphilis and parasitic infections), hair and nail disorders, pigmentary disorders, benign skin tumors and drug eruptions were significantly decreased during the COVID-19 pandemic years, the percentage of other dermatitis, fungal and viral skin infections, acne, psoriasis, urticaria, vesiculobullous and autoimmune diseases were increased. Conclusion: The COVID-19 pandemic had a minimal effect on the average weekly skin clinic visits, but the diagnosed skin diseases pattern was affected. Knowing the pattern of skin diseases may help aid hospitals to better prepare for future pandemics in securing appropriate medications and supplies and training the medical teams.

Evaluation of non-endemic pemphigus foliaceus in a large series of patients: a single-center retrospective study from Turkey focuses on the relapses

BACKGROUND

Pemphigus foliaceus is exceedingly rare around the world, except within the few regions where it occurs as an endemic variant. Various factors can trigger immune mechanisms that induce pemphigus foliaceus or worsen its course.

OBJECTIVE

To determine the demographic and clinical characteristics of the patients with pemphigus foliaceus in a large series from a non-endemic country, investigate the triggering factors, and seasonal patterns.

METHODS

The data of the patients diagnosed with pemphigus foliaceus in the study's center between 1989-2018 were retrospectively analyzed.

RESULTS

Sixty-eight patients (mean age, 45.7 ± 14.5 years) were included in the study. The number of onsets reached its peak in spring-summer (p = 0.008). A total of 117 relapses occurred in 42 patients and were most common in spring-summer (not significant). Specific trigger factors were detected in 45 relapses. In the other 72 relapses, the peak was observed in spring-summer (p = 0.005). There were no significant differences in the demographic and clinical variables investigated between relapsed and non-relapsed patients.

STUDY LIMITATIONS

Retrospective design.

CONCLUSIONS

Triggering factors could not be identified in more than half of the relapses in the study's series. The subgroup of relapses (without identified causes), as well as the onsets of the disease, showed a significant seasonal variation with a peak in spring-summer; however, the seasonal variable did not justify the total group of relapses. Although the seasonal variation may be caused by a combination of factors, UV radiation should be considered a trigger factor for the peaks in spring-summer, particularly in Turkey.

Application of photodynamic therapy in immune-related diseases

Photodynamic therapy (PDT) is a therapeutic modality that utilizes photodamage caused by photosensitizers and oxygen after exposure to a specific wavelength of light. Owing to its low toxicity, high selectivity, and minimally invasive properties, PDT has been widely applied to treat various malignant tumors, premalignant lesions, and infectious diseases. Moreover, there is growing evidence of its immunomodulatory effects and potential for the treatment of immune-related diseases. This review mainly focuses on the effect of PDT on immunity and its application in immune-related diseases.

Drug-induced pemphigus: A systematic review of 170 patients

Pemphigus encompasses a rare heterogeneous group of autoimmune blistering diseases characterized by cutaneous and/or mucosal blistering. Multiple factors, such as some specific types of drugs, have been found to be involved in the induction of pemphigus. Here, we have designed a systematic review by searching PubMed/Medline and Embase databases to find the drugs, involved in pemphigus induction and exacerbation (updated on 19 August 2019). From 1856 initially found articles, 134 studies (198 patients; 170 patients in the drug-induced patients and 28 in exacerbation group) have been included. Regarding drug-induced cases, the mean age was 57.19 ± 16.9-year-old (ranged 8-105), and patients had developed pemphigus within a mean of 154.27 days. Pemphigus vulgaris (38.9%), pemphigus foliaceus (33.5%), and paraneoplastic pemphigus (3.6%) were the most common subtypes. Furthermore, penicillamine (33.1%), captopril (7.7%), and bucillamine (6.5%) were the most reported drugs related to pemphigus induction; penicillamine was associated with the most persistent disease. Regardless of disease subtype, cutaneous, mucocutaneous, and mucosal involvements were reported in 68.6%, 30.1%, and 1.3% of patients, respectively. In total, the IgG deposition in the pathological studies, being positive for autoreactive antibodies in the serum against desmoglein 3 (Dsg3), and desmoglein 1 (Dsg1), were reported in 93%, 34.9%, and 72.7% of reported patients, respectively. Regarding the management of such patients, in 75% of healed cases, treatment (mainly transient systemic and topical corticosteroids and/or azathioprine) was needed besides stopping the probable pemphigus-inducing culprit drug, while drug cessation was enough to control the disease in 25%. As the outcomes, the lesions in 129 of 147 (87.8%) patients had been healed, while in 18 (12.2%), no healing was reported; fifteen out of 18 had died. In conclusion, some specific groups of treatments can induce pemphigus, including penicillamine, captopril, and bucillamine; despite the similar clinical and pathological manifestations to classical pemphigus, most of the cases are less severe and have a better prognosis.

Rituximab in practice: Clinical evaluation of patients with pemphigus after rituximab administration

Pemphigus Vulgaris (PV) is a rare autoimmune blistering disease, which mainly causes mucosal and/or cutaneous lesions. In June 2018, FDA approved Rituximab (RTX)-a B-cell depleting agent-for the management of patients with moderate-to-severe pemphigus. Although the majority of patients respond well to this drug, some do not reach complete remission with a single cycle of RTX. In this review, following an overview of RTX and its clinical outcomes, we have focused on the possible outcomes after RTX therapy in patients with PV. The response is defined into four main categories; complete responders, partial responders, nonresponders, and paradoxical reactions, based on three possibilities of reaching the consolidation phase after 3 months, reaching remission until 6 months, and the ability of corticosteroid tapering in 6 months after RTX administration. Concerning the safety of RTX, three categories of infusion reactions, short and long-term side effects are discussed. Additionally, we have suggested approaches for the evaluation of clinical and serological responses at different critical time-points, including 1, 2, 3, and 6 months after RTX administration. Finally, available markers to predict the response to RTX and research gaps in the field of RTX therapy have been summarized.

Autoreactive T cells in pemphigus: perpetrator and target

Pemphigus vulgaris (PV) is an autoimmune blistering disease, in which autoantibodies against epidermal cadherins, such as desmoglein (Dsg)1 and Dsg3, lead to the development of blisters and erosions on the skin and mucous membranes. Autoreactive CD4+ T cells are essential for the induction and perpetuation of the disease by interaction with B cells producing autoantibodies. PV has a strong genetic association with certain human leucocyte antigen (HLA) alleles with HLA-DRB1*04:02 and LA-DQB1*05:03 being the most prevalent in patients. Recently, genome-wide association studies have provided a new approach to identify single nucleotide polymorphisms, alongside the known association with HLA alleles. Loss of tolerance against Dsgs and other autoantigens is a critical event in the pathogenesis of PV. Epitope spreading contributes to the progression of PV, leading to an extension of the Dsg-specific autoimmune response to other molecular epitopes of autoantigens, such as desmocollins or muscarinic receptors. Alterations in CD4+CD25+ FoxP3+ regulatory T cells are thought to contribute to the development of PV representing a suitable target for therapeutic interventions. Several CD4+ T-cell subsets and cytokines are involved in the pathogenesis of PV, while Th2 cells are the extensively studied population. Recently, other T cell subsets like T follicular helper cells and Th17 have gained attention as new potential players in PV pathogenesis. The involvement of local autoantibody production in the lesional skin of PV patients in tertiary lymphoid organs is currently discussed but not yet clarified. In this study, we reviewed the current knowledge about the development, characteristics and function of autoreactive T cells in pemphigus and present current new T cell-targeted therapeutic approaches.

The First Reported Case of Metoprolol-Induced Pemphigus Foliaceus in the United States: A Critical Report and Review of Literature

Pemphigus is a rare family of autoimmune disorders characterized by epithelial and mucosal blisters. Pemphigus foliaceus (PF) commonly affects the scalp, face, and trunk. Lesions often arise as superficial blisters and develop into scaly, crusted erosions. Management includes corticosteroids with immunosuppressants. Novel therapies include immunoadsorption and active clinical trials. We present the only reported case of metoprolol-induced PF in the United States (US), with an extremely complicated hospital course. 

A 66-year-old male patient with a history of hypertension, diabetes, and hyperlipidemia presented to his doctor with a blistering, pruritic rash that started after switching to metoprolol for hypertension treatment. 

PF is very rare in North America. Given its solely superficial penetration, it creates no direct fatal complication. However, the developing blisters and subsequent wounds are susceptible to a wide array of secondary infections, which can be life-threatening.

The pathogenesis of bullous skin diseases

Bullous skin diseases are a group of dermatoses characterized by blisters and bullae in the skin and mucous membranes. The etiology and pathogenesis of bullous skin diseases are not completely clear. The most common are pemphigus and bullous pemphigoid (BP). Autoantibodies play critical roles in their pathogenesis. Abnormalities in the adhesion between keratinocytes in patients with pemphigus leads to acantholysis and formation of intra-epidermal blisters. Anti-desmoglein autoantibodies are present both in the circulation and skin lesions of patients with pemphigus. The deficient adhesion of keratinocytes to the basement membrane in BP patients gives rise to subepidermal blisters. Autoantibodies against the components of hemidesmosome can be detected in BP patients. Many novel therapeutics based on knowledge of the pathogenesis have emerged in recent years.

Single-nucleotide polymorphisms associated with pemphigus vulgaris: Potent markers for better treatment and personalized medicine

Pemphigus vulgaris (PV) is a rare autoimmune blistering disorder, which could affect both skin and mucosal surfaces. There is increasing evidence that genetics plays a critical role in PV development, severity and prognosis. Single-nucleotide polymorphisms (SNPs) are the most common type of genetic variation among people and have been widely evaluated in most diseases. However, there are few studies regarding the roles of SNPs in the PV. Here, we reviewed both pathogenic and protective roles of the SNPs in non-HLA genes regarding the PV. Among the large number of studied SNPs, it was found that several SNPs in different genes might control the susceptibility of PV, including TNFA (rs361525, rs1800629, rs1800629), IL10 (rs1800871, rs1800896, rs1800871, and rs1800872), IL6 (rs1800795), CTLA4 (rs231775), ICOS (rs10932029), CD86 (rs1129055), DSG3 (rs8085532, rs3911655, rs3848485, rs3794925, rs1466379), ST18 (rs2304365, rs17315309) and TAP2 (rs7454108), probably in a population-specific manner. Moreover, SNPs in glucocorticoid receptor, also known as nuclear receptor subfamily 3 group C member 1 (NR3C1) gene, including rs11745958, rs17209237, rs33388, rs7701443 as well as rs116855232 at NUDT15, seem to be associated with therapeutic outcomes in PV patients. Additionally, variations in the other genes involved in the drugs' metabolisms, pharmacokinetics and pharmacodynamics such as rs396991 in FCGR3A gene could be used for the prediction of clinical response to drugs and side effects. Taken together, SNPs seem to be valuable tools for better management of PV patients. Further studies need to be conducted to evaluate SNPs in genes that control immune responses and apoptosis.

The Dynamics of the Skin's Immune System

The skin is a complex organ that has devised numerous strategies, such as physical, chemical, and microbiological barriers, to protect the host from external insults. In addition, the skin contains an intricate network of immune cells resident to the tissue, crucial for host defense as well as tissue homeostasis. In the event of an insult, the skin-resident immune cells are crucial not only for prevention of infection but also for tissue reconstruction. Deregulation of immune responses often leads to impaired healing and poor tissue restoration and function. In this review, we will discuss the defensive components of the skin and focus on the function of skin-resident immune cells in homeostasis and their role in wound healing.

The potential roles of herpesvirus and cytomegalovirus in the exacerbation of pemphigus vulgaris

Background

Among exogenous etiologies, the critical role of microbial agents such as herpesviruses (HSV1/2) and cytomegalovirus (CMV) in triggering and flaring autoimmune conditions such as pemphigus vulgaris (PV) has been recently discovered.

Objectives

The present study aimed to investigate the plausible role of these viruses in the exacerbation of PV using serological and molecular methods.

Patients/Methods

Sixty patients with PV (30 with relapse type and 30 with remission type) were recruited for the purpose of this case-control study. Skin, mucosal, and throat specimens were obtained and examined for viruses by reverse transcriptase polymerase chain reaction. To determine the immunoglobulin G (IgG) titer, enzyme-linked immunosorbent assay was used.

Results

Desmoglein1-specific IgG was positive in 56.7% of patients with the relapse form and in 20.0% of those with the remission form indicating a significant difference across the 2 groups (P = 0.003), but the rate of positivity for desmoglein3-specific IgG in the relapse and remission types was 76.7% and 63.3%, respectively, with no significant difference (P = 0.260). There was no difference in the mean levels of HSV-IgG and CMV-IgG in the relapse and remission groups. HSV and CMV positivity in PV patients was independent of the site of the samples. Using the multivariable linear regression model, the level of CMV-IgG in PV patients was directly affected by female sex and advanced ages.

Conclusions

Our study could not demonstrate the role of HSV1/2 and CMV as triggering factors for PV exacerbation. Further studies are needed to evaluate the potential role of these viruses in PV exacerbation especially considering demographic variables.