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

INTRODUCTION: Linear IgA dermatosis (LAD) is a rare subepidermal autoimmune bullous disease (AIBD) defined by predominant or exclusive immune deposits of immunoglobulin A at the basement membrane zone of skin or mucous membranes. This disorder is a rare, clinically and immunologically heterogeneous disease occurring both in children and in adults. The aim of this project is to present the main clinical features of LAD, to propose a diagnostic algorithm and provide management guidelines based primarily on experts' opinion because of the lack of large methodologically sound clinical studies. METHODS: These guidelines were initiated by the European Academy of Dermatology and Venereology (EADV) Task Force Autoimmune Bullous Diseases (AIBD). To achieve a broad consensus for these S2k consensus-based guidelines, a total of 29 experts from different countries, both European and non-European, including dermatologists, paediatric dermatologists and paediatricians were invited. All members of the guidelines committee agreed to develop consensus-based (S2k) guidelines. Prior to a first virtual consensus meeting, each of the invited authors elaborated a section of the present guidelines focusing on a selected topic, based on the relevant literature. All drafts were circulated among members of the writing group, and recommendations were discussed and voted during two hybrid consensus meetings. RESULTS: The guidelines summarizes evidence-based and expert opinion-based recommendations (S2 level) on the diagnosis and treatment of LAD. CONCLUSION: These guidelines will support dermatologists to improve their knowledge on the diagnosis and management of LAD.

Serum reactivity in dermatitis herpetiformis: an international multicentre study.

BACKGROUND: Dermatitis herpetiformis (DH) is a rare gluten-induced skin disorder characterized predominantly by IgA autoantibodies against endomysium, tissue transglutaminase (TG2/tTG), epidermal transglutaminase (TG3/eTG) and deamidated gliadin. To date, circulating autoantibody reactivity has not been systematically described. OBJECTIVES: Characterization of serum reactivities in DH. METHODS: This multicentre international study analysed sera from 242 patients with DH taken at the time of initial diagnosis. DH-specific IgA and IgG serum autoantibodies were analysed by indirect immunofluorescence (IF) on monkey oesophagus, and by enzyme-linked immunosorbent assay (ELISA) based on recombinant TG2/tTG, TG3/eTG and deamidated gliadin (GAF3X). RESULTS: IgA indirect IF microscopy on monkey oesophagus revealed the highest reactivity (84.3%; specificity 100%) followed by IgA TG2/tTG ELISA (78.5%, specificity 99.0%), IgA TG3/eTG ELISA (72.7%, specificity 95.0%) and IgA GAF3X ELISA (69.0%, specificity 98.5%). CONCLUSIONS: Serum IgA and IgG autoantibodies against endomysium, TG2/tTG, TG3/eTG and deamidated gliadin are highly prevalent in DH. Indirect IF microscopy on monkey oesophagus (IgA) provides the highest diagnostic accuracy that can be further enhanced by 4.5% when combined with IgA TG2/tTG ELISA.

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.

Multicenter prospective study on multivariant diagnostics of autoimmune bullous dermatoses using the BIOCHIP technology.

BACKGROUND: The current standard in the serologic diagnosis of autoimmune bullous diseases (AIBD) is a multistep procedure sequentially applying different assays. In contrast, the BIOCHIP Mosaic technology combines multiple substrates for parallel analysis by indirect immunofluorescence. METHODS: Sera from 749 consecutive, prospectively recruited patients with direct immunofluorescence-positive AIBD from 13 international study centers were analyzed independently and blinded by using (1) a BIOCHIP Mosaic including primate esophagus, salt-split skin, rat bladder, monkey liver, monkey liver with serosa, recombinant BP180 NC16A, and gliadin GAF3X, as well as HEK293 cells expressing recombinant desmoglein 1, desmoglein 3, type VII collagen, and BP230 C-terminus and (2) the conventional multistep approach of the Department of Dermatology, University of Lübeck. RESULTS: In 731 of 749 sera (97.6%), specific autoantibodies could be detected with the BIOCHIP Mosaic, similar to the conventional procedure (725 cases, 96.8%). The Cohen κ for both serologic approaches ranged from 0.84 to 1.00. In 6.5% of sera, differences between the 2 approaches occurred and were mainly attributed to autoantigen fragments not present on the BIOCHIP Mosaic. LIMITATIONS: Laminin 332 and laminin γ1 are not represented on the BIOCHIP Mosaic. CONCLUSIONS: The BIOCHIP Mosaic is a standardized time- and serum-saving approach that further facilitates the serologic diagnosis of AIBD.

Diagnosis and management of pemphigus: Recommendations of an international panel of experts.

BACKGROUND: Several European countries recently developed international diagnostic and management guidelines for pemphigus, which have been instrumental in the standardization of pemphigus management. OBJECTIVE: We now present results from a subsequent Delphi consensus to broaden the generalizability of the recommendations. METHODS: A preliminary survey, based on the European Dermatology Forum and the European Academy of Dermatology and Venereology guidelines, was sent to a panel of international experts to determine the level of consensus. The results were discussed at the International Bullous Diseases Consensus Group in March 2016 during the annual American Academy of Dermatology conference. Following the meeting, a second survey was sent to more experts to achieve greater international consensus. RESULTS: The 39 experts participated in the first round of the Delphi survey, and 54 experts from 21 countries completed the second round. The number of statements in the survey was reduced from 175 topics in Delphi I to 24 topics in Delphi II on the basis of Delphi results and meeting discussion. LIMITATIONS: Each recommendation represents the majority opinion and therefore may not reflect all possible treatment options available. CONCLUSIONS: We present here the recommendations resulting from this Delphi process. This international consensus includes intravenous CD20 inhibitors as a first-line therapy option for moderate-to-severe pemphigus.

Celiac-Related Autoantibodies and IL-17A in Bulgarian Patients with Dermatitis Herpetiformis: A Cross-Sectional Study.

Background and objectives: Dermatitis herpetiformis (DH) is a blistering dermatosis, which shares common immunologic features with celiac disease (CD). The aim of the present study was to explore the performance of a panel of CD-related antibodies and IL-17A in Bulgarian patients with DH. Materials and Methods: Serum samples from 26 DH patients at mean age 53 ± 15 years and 20 healthy controls were assessed for anti-tissue transglutaminase (anti-tTG), anti-deamidated gliadin peptides (anti-DGP), anti-actin antibodies (AAA), and IL-17A by enzyme linked immuno-sorbent assay (ELISA), as well as anti-tTG, anti-gliadin (AGA), and anti-Saccharomyces cerevisiae antibodies (ASCA) using immunoblot. Results: The average serum levels of anti-tTG, anti-DGP, AGA, AAA, and the cytokine IL-17A were at significantly higher levels in patients with DH compared to the average levels in healthy persons which stayed below the cut-off value (p < 0.05). Anti-DGP and anti-tTG antibodies showed the highest diagnostic sensitivity and specificity, as well as acceptable positive and negative predictive value. None of the healthy individuals was found positive for the tested antibodies, as well as for ASCA within the DH group. All tests showed good to excellent correlations (r = 0.5 ÷ 0.9, p < 0.01). Conclusions: Although the diagnosis of DH relies on skin biopsy for histology and DIF, serologic testing of a panel of celiac-related antibodies could be employed with advantages in the diagnosing process of DH patients. Furthermore, DH patients who are positive for the investigated serologic parameters could have routine monitoring for gastrointestinal complications typical for the gluten-sensitive enteropathy.

Prospective studies on the routine use of a novel multivariant enzyme-linked immunosorbent assay for the diagnosis of autoimmune bullous diseases.

BACKGROUND: Serologic diagnosis of autoimmune blistering disease (AIBD) usually follows a sophisticated multistep algorithm. OBJECTIVE: We sought validation of a multivariant enzyme-linked immunosorbent assay (ELISA) in the routine diagnosis of AIBD. METHODS: The multivariant ELISA comprising 6 recombinant immunodominant forms of major AIBD target antigens, ie, desmoglein 1, desmoglein 3, envoplakin, BP180, BP230, and type VII collagen was applied in: (1) a cohort of well-characterized AIBD (n = 173) and control sera (n = 130), (2) a prospective multicenter study with 204 sera from patients with newly diagnosed AIBD with positive direct immunofluorescence microscopy, and (3) a prospective monocenter study with 292 consecutive sera from patients with clinical suspicion of AIBD in comparison with the conventional multistep diagnostic algorithm. RESULTS: Concordant results in the multivariant ELISA compared with direct immunofluorescence microscopy were seen in 94% of patients with pemphigus and 71% of patients with pemphigoid (Cohen κ value, 0.95 and 0.66) and with the conventional multistep diagnostic approach in 91% of patients with pemphigus and 88% of patients with bullous pemphigoid and 93% of autoantibody-negative sera (Cohen κ, 0.95, 0.84, and 0.78). LIMITATIONS: IgA autoantibodies and less common target antigens were not analyzed. CONCLUSIONS: The multivariant ELISA is a practical, highly standardized, and widely available novel diagnostic tool for the routine diagnosis of AIBD.

Artificial Intelligence in Autoimmune Bullous Dermatoses.

Dermatologists treating patients with Autoimmune Bullous Dermatoses (AIBDs), as well as the patients themselves, encounter challenges at every stage of their interaction, including dermatological and comorbidities assessment, diagnosis, prognosis evaluation, treatment, and follow-up monitoring. We summarize the current and potential future clinical applications of artificial intelligence (AI) in the field of AIBDs. Recent research and AI models have demonstrated their potential to enhance or may already be contributing to advancements in every phase of the comprehensive diagnosis and personalized treatment process in AIBDs, providing patients, clinicians, and administrators with valuable support. Image recognition AI systems might assist precise clinical diagnoses of various diseases, including AIBDs, and could offer consistent and reliable scoring of disease severity. Automated and standardized AI-assisted laboratory methods could improve the accuracy and decrease the time and cost of gold-standard tests such as direct and indirect immunofluorescence. The studies and tools discussed in this article, although in the early stages, might be a small precursor to a transformative shift in the way we take care of patients with chronic skin diseases, including AIBDs.

Netherton syndrome-A therapeutic challenge in childhood.

Key Clinical Message: High-dose intravenous immunoglobulin exhibits great potential in the treatment of Netherton syndrome. Abstract: Netherton syndrome (NS) is a rare autosomal recessive genodermatosis (OMIM #256500) characterized by superficial scaling, atopic manifestations, and multisystemic complications. It is caused by loss-of-function mutations in the SPINK5 gene, which encode a key kallikrein protease inhibitor. There are two subtypes of the syndrome that differ in clinical presentation and immune profile: ichthyosiform erythroderma and ichthyosis linearis circumflexa. NS is a multisystemic disease with numerous extracutaneous manifestations. Current therapy for patients with NS is mainly supportive, as there is no curative or specific treatment, especially for children with NS, but targeted therapies are being developed. We describe an 8-year-old boy with genetically proven NS treated with intravenous immunoglobulin for recurrent skin and systemic infections from infancy, growth retardation, and associated erythroderma. Under this therapy, his skin status, infectious exacerbations, and quality of life all improved. Knowledge of the cytokine-mediated pathogenesis of NS and the development of new biologic drugs open new possibilities for NS patients. However, the different therapeutic options have been applied in a limited number of cases, and variable responses have been shown. Randomized controlled trials with a sufficient number of patients stratified and treated according to their specific immune profile and clinical phenotype are needed to evaluate the safety and efficacy of treatment options for patients with NS.

Rosacea: The eyes have it.

Rosacea is a chronic inflammatory dermatosis typically affecting the facial skin but also the eyes. With its chronic course with fluctuating episodes of flashing, redness, papulopustules, and nodules it poses a severe psychologic burden to the affected individuals. In addition to the facial changes, more than half of the patients have ocular involvement ranging from blepharitis and conjunctival hyperemia to more severe ophthalmic damage, and even blindness. Clinically, the ocular involvement in rosacea includes meibomian gland dysfunction with relapsing hordeola and chalazia, diffuse hyperemic conjunctivitis, photophobia, episcleritis, or kerato-conjunctivitis, and in rare cases, corneal ulcers. These are mainly observed in adult patients but can also occur in children. Depending on the degree of cutaneous or ocular findings, patients with rosacea may present first to the dermatologist or to the ophthalmologist. Both specialists should be aware of the potential oculocutaneous involvement. Any ocular complaints expressed by the patient in the setting of a dermatologist's office should be referred promptly for an ophthalmologic examination. Conversely, signs suggestive of rosacea in the eye should lead the ophthalmologist to consider underlying skin disease. A timely interdisciplinary collaboration is paramount for the earlier diagnosis and treatment, thus preventing permanent eye impairment in this chronic dermatosis.

Case Report: Coexistence of bullous pemphigoid and psoriasis: Therapeutic challenge and IL17A-targeted parallel treatment strategy.

Autoimmune blistering diseases of the skin have all been reported in patients with psoriasis, bullous pemphigoid (BP) being the most frequently observed. The pathophysiologic triggers for BP in psoriatic patients are unclear. Recent observational studies have suggested that chronic psoriatic inflammation may cause pathological changes to the basement membrane zone, thus inducing autoimmunity against BP antigens through cross reactivity and "epitope spreading." The coexistence of BP and psoriasis poses challenging therapeutic dilemmas related to the incompatibility of their standard treatments. Considering the probable common immunologic mechanisms in the pathogenesis of these inflammatory skin disorders, a suitable treatment regimen should be applied for their parallel control. We report three patients, who developed BP in the course of preceding long-lasting psoriasis. Secukinumab was administered as first-line treatment with promising therapeutic effect for both skin disorders and long-term disease control in two of the cases. In the third case, parallel disease control was initially achieved with methotrexate. A few years later, secukinumab was used for the treatment of a relapse of both dermatoses but worsening of BP was observed and methotrexate was reintroduced. Our experience on the therapeutic potential of secukinumab in BP is supported by the data in the literature. Recently, it was demonstrated that the proinflammatory cytokine IL17A has a functional role in the process of skin inflammation in BP, similarly to psoriasis. IL17A inhibition has emerged as a promising therapeutic strategy in patients with extensive or refractory BP but paradoxical development of BP after secukinumab treatment for psoriasis has also been described. This controversy emphasizes the need for further investigation into the development of optimal treatment strategies and recommendations.

Differences among Indian and European pemphigus patients based on demographics, clinical parameters and propensity for relapse: results of a prospective bicontinental cohort study.

Limited studies have explored pemphigus variations among different ethnic groups residing in their respective geographical locations. This bicontinental study aimed to compare clinical and immunological parameters in Indian and European pemphigus patients in complete remission, off therapy, or on minimal therapy. 105 patients (India, n= 75; Bulgaria, n=15; Greece, n=15) with pemphigus vulgaris (PV) or pemphigus foliaceous (PF) in complete remission on minimal therapy (n=64) or complete remission off therapy (n=41) were recruited. Demographic, clinical, and immunological parameters were compared. Indian patients were significantly younger, the maximal disease severity during the preceding active disease phase was significantly lower, and treatment duration until complete remission was significantly shorter, compared to European patients. European patients had significantly higher anti-Dsg3 serum levels and higher IgG positivity rate based on direct immunofluorescence microscopy at baseline. Furthermore, European patients revealed higher CD19, CD19+ CD27+ cell counts, compared with patients from India. Of note, none of the European patients (n=30) relapsed within the study period, in contrast to 29/75 (38.6%) Indian patients. Treatment strategies differed significantly between the two cohorts, with more frequent utilization of rituximab to achieve remission in the Indian cohort, while prednisolone was more widely used for maintaining remission in the European cohort. The observed heterogeneity of pemphigus among patients of different ethnicities in terms of demographics, clinical parameters, and propensity for relapse may be due to genetic background or different treatment strategies.

Characterization of the skin microbiota in bullous pemphigoid patients and controls reveals novel microbial indicators of disease.

INTRODUCTION: Bullous pemphigoid (BP) is the most common autoimmune blistering disease. It predominately afflicts the elderly and is significantly associated with increased mortality. The observation of age-dependent changes in the skin microbiota as well as its involvement in other inflammatory skin disorders suggests that skin microbiota may play a role in the emergence of BP blistering. We hypothesize that changes in microbial diversity associated with BP might occur before the emergence of disease lesions, and thus could represent an early indicator of blistering risk. OBJECTIVES: The present study aims to investigate potential relationships between skin microbiota and BP and elaborate on important changes in microbial diversity associated with blistering in BP. METHODS: The study consisted of an extensive sampling effort of the skin microbiota in patients with BP and age- and sex-matched controls to analyze whether intra-individual, body site, and/or geographical variation correlate with changes in skin microbial composition in BP and/or blistering status. RESULTS: We find significant differences in the skin microbiota of patients with BP compared to that of controls, and moreover that disease status rather than skin biogeography (body site) governs skin microbiota composition in patients with BP. Our data reveal a discernible transition between normal skin and the skin surrounding BP lesions, which is characterized by a loss of protective microbiota and an increase in sequences matching Staphylococcus aureus, a known inflammation-promoting species. Notably, Staphylococcus aureus is ubiquitously associated with BP disease status, regardless of the presence of blisters. CONCLUSION: The present study suggests Staphylococcus aureus may be a key taxon associated with BP disease status. Importantly, we however find contrasting patterns in the relative abundances of Staphylococcus hominis and Staphylococcus aureus reliably discriminate between patients with BP and matched controls. This may serve as valuable information for assessing blistering risk and treatment outcomes in a clinical setting.

The gut microbiome in bullous pemphigoid: implications of the gut-skin axis for disease susceptibility.

Bullous pemphigoid (BP) is an autoimmune blistering disease that primarily affects the elderly. An altered skin microbiota in BP was recently revealed. Accumulating evidence points toward a link between the gut microbiota and skin diseases; however, the gut microbiota composition of BP patients remains largely underexplored, with only one pilot study to date, with a very limited sample size and no functional profiling of gut microbiota. To thoroughly investigate the composition and function of the gut microbiota in BP patients, and explore possible links between skin conditions and gut microbiota, we here investigated the gut microbiota of 66 patients (81.8% firstly diagnosed) suffering from BP and 66 age-, sex-, and study center-matched controls (CL) with non-inflammatory skin diseases (132 total participants), using 16S rRNA gene and shotgun sequencing data. Decreased alpha-diversity and an overall altered gut microbial community is observed in BP patients. Similar trends are observed in subclassifications of BP patients, including first diagnoses and relapsed cases. Furthermore, we observe a set of BP disease-associated gut microbial features, including reduced Faecalibacterium prausnitzii and greater abundance of pathways related to gamma-aminobutyric acid (GABA) metabolism in BP patients. Interestingly, F. prausnitzii is a well-known microbiomarker of inflammatory diseases, which has been reported to be reduced in the gut microbiome of atopic dermatitis and psoriasis patients. Moreover, GABA plays multiple roles in maintaining skin health, including the inhibition of itching by acting as a neurotransmitter, attenuating skin lesions by balancing Th1 and Th2 levels, and maintaining skin elasticity by increasing the expression of type I collagen. These findings thus suggest that gut microbiota alterations present in BP may play a role in the disease, and certain key microbes and functions may contribute to the link between gut dysbiosis and BP disease activity. Further studies to investigate the underlying mechanisms of the gut-skin interaction are thus clearly warranted, which could aid in the development of potential therapeutic interventions.

Case Report: Rowell Syndrome-Like Flare of Cutaneous Lupus Erythematosus Following COVID-19 Infection.

The current COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had an important impact on dermatology practice, posing diagnostic and therapeutic challenges especially in patients with inflammatory and autoimmune skin disorders. Disease-specific and nonspecific cutaneous manifestations have been increasingly reported in the spectrum of COVID-19 but the influence of the infection on pre-existing dermatologic diseases has not been clearly defined. There has been a debate in the literature as to whether patients suffering from autoimmune dermatoses, including cutaneous lupus erythematosus (CLE), are at increased risk of SARS-CoV-2 infection, as well as if they experience worsening of their lupus erythematosus (LE)-related clinical symptoms. This article reports on a case of Rowell syndrome occurring after COVID-19 in a 67-year old woman with pre-existing chronic CLE manifesting with few discoid lesions on the face, scalp, and upper chest, successfully controlled with topical corticosteroids and photoprotection. Erythema multiforme (EM)-like eruption developed approximately two weeks after the SARS-CoV-2 infection, the latter being confirmed by positive nasopharyngeal swab and successfully treated with systemic antibiotics and antiaggregants. Diffuse hair loss and patches of cicatricial alopecia were also present upon scalp examination. Laboratory workup, including routine tests, histologic, immunofluorescent, and serologic investigations, was supportive to the diagnosis. Administration of topical and systemic corticosteroids along with peroral hydroxychloroquine resulted in the progressive improvement of the cutaneous lesions. Rowell syndrome is a rare entity in the spectrum of LE, characterized by EM-like lesions, photosensitivity, and positive antinuclear and anti-Ro antibodies, that is currently considered to be a variant of subacute CLE (SCLE). Several cases of SCLE have been described in association with medications, including anti-SARS-CoV-2 vaccines but only a few reports incriminate the infection itself as a potential exacerbating factor. Based on the clinical course of the disease, we suggest that the observed Rowell syndrome-like flare of CLE was related to the COVID-19 infection in this patient.

Association of specific HLA alleles and haplotypes with pemphigus vulgaris in the Bulgarian population.

Pemphigus vulgaris (PV) is an autoimmune bullous dermatosis with uneven geographic distribution and higher incidence in certain populations. In previous studies, a relatively high incidence of PV was reported in Bulgaria (0.47/100,000/year) comparable to that in other countries. The genetic background was considered responsible for the disease susceptibility, and multiple reports have proven PV to be an HLA-associated condition. The aim of our study was to analyze the role of genetic factors in the development of PV in Bulgaria. HLA genotyping was performed in 56 PV patients, ethnic Bulgarians whose diagnosis was confirmed based on clinical, histological, and immunofluorescent findings. The control group consisted of 204 healthy individuals from the Bulgarian population without evidence for HLA-associated autoimmune diseases. HLA-A,-B,-DRB1,-DQB1 analysis was performed by PCR-SSP. Our results revealed predisposing associations with DRB1*14, DRB1*04:02, and B*38, B*55, while allele DRB1*03:01 and the corresponding haplotypes were significantly decreased in the PV patients. The predisposing role of these alleles has been observed in other populations. All reported predisposing DRB1 alleles have the same amino acids at key positions of the beta chain of the HLA molecules, 26 (Phe), 67 (Leu or Ileu), 70 and 71 (hydrophobic AA: Gln, Arg, Asp, or Glu), and 86 (Val), which is important for the selective presentation of desmoglein 3 peptides. Additionally, specific alleles HLA-A*01 and DRB1*11 were identified with decreased frequencies in the patients' group, the last one being a common protective allele for autoimmune diseases in the Bulgarian population. The elucidation of the role of genetic factors for the development of pemphigus will help explain its higher incidence and clinical variability in certain populations.

Impact of COVID-19 on autoimmune blistering diseases.

Since the beginning of the COVID-19 outbreak, attention has gradually moved from the respiratory manifestations of the disease toward its dermatologic aspects. The need for wearing personal protective measures and their cutaneous side effects, detection of related or specific COVID-19 skin eruptions, and the evaluation of certain risk groups of immunosuppressed dermatologic patients have initiated significant discussions about various therapeutic interventions and, in particular, about biologic therapy for psoriasis and for autoinflammatory, orphan, or malignant cutaneous disorders. Autoimmune bullous dermatoses have been of concern due to their chronic course, at times life-threatening prognosis, and the need for prolonged and often aggressive immunomodulatory therapy. We have summarized the current knowledge regarding the impact of COVID-19 infection on autoimmune bullous dermatoses, including recommendations for the main treatment strategies, available patient information, and the registries organized for documentation during the COVID-19 pandemic.

Drug repurposing of dermatologic medications to treat coronavirus disease 2019: Science or fiction?

No pharmaceutical products have been demonstrated to be safe and effective to specifically treat coronavirus disease 2019 (COVID-19); therefore, the therapy administered to infected patients remains symptomatic and empiric. Alongside the development of new, often high-cost drugs, a different tactic is being applied in parallel, investigating long-established, inexpensive medications originally designed for a variety of diseases to study their potential in treating COVID-19. The skin is the largest organ of the human body. With more than 3,000 skin conditions identified, the specialty of dermatology offers a rich armamentarium of systemic therapeutic agents aimed to treat the various chronic immunologically mediated, metabolic, infectious, occupational, inherited, or paraneoplastic dermatoses. Dermatologists have extensive experience with many drugs that have demonstrated promising in vitro antiviral action (directly targeting the viral replication). Many of these drugs have been used as nonspecific immunosuppressive strategies, such as glucocorticoids, synthetic antimalarials, colchicine, or other immunomodulators, and a number of targeted therapeutics have been directed at controlling hyperinflammatory processes similar to the "cytokine storm" associated with COVID-19 infection. We discuss several dermatologic drugs that have already been used or may have a promising role in the treatment of COVID-19.

Direct patient-to-physician teledermatology: Not a flash in the pan(demic).

Dermatology is a clinical and visual discipline, which makes it the quintessential medical specialty for spot diagnosis and telemedicine. The COVID-19 pandemic has led to an unprecedented worldwide renaissance of teledermatology (TD). It has helped deliver high-quality medical care, while protecting the medical personnel and vulnerable patients from potential infection. Examining a patient from a distance through digital photography has many drawbacks, including lack of physical touch, difficulties in performing full body examinations, and several legal and ethical issues. We summarize have summarized the more common pitfalls and highlight the key aspects of direct patient-to-physician TD. Basic practical advice includes the use of TD for obtaining patient history, examining patient-captured photographs for inflammatory skin disease, and skin cancer screening.