Role of physical factors in the pathogenesis of bullous pemphigoid: Case report series and a comprehensive review of the published work

Risk of bullous pemphigoid and pemphigus in patients on chronic dialysis: A nationwide population-based cohort study

Bullous pemphigoid has a high incidence among dialysis patients. However, whether or not chronic dialysis is an independent risk factor of bullous pemphigoid remains unclear. We aimed to investigate the effect of chronic dialysis on the development of bullous pemphigoid and pemphigus. We performed a retrospective cohort study using records from Taiwan's National Health Insurance Research Database between 2008 and 2019. We identified a dialysis cohort that included patients on chronic hemodialysis and peritoneal dialysis, and the hazard ratios (HRs) for bullous pemphigoid and pemphigus were compared with those of a sex-, age-, and index-matched cohort, then the results were adjusted for various confounding factors. Among 93 538 patients on chronic dialysis and 93 538 patients in the control group, 287 and 139 developed incident bullous pemphigoid, and 45 and 35 developed incident pemphigus after a median follow-up of 3.7 and 5.6 years, respectively. The incidence rates of bullous pemphigoid in the dialysis patients and the control group were 74.2 and 25.2 per 100 000 person-years, respectively (difference between groups, P < 0.0001). The incidence rates of pemphigus in the dialysis patients and the control group were 11.6 and 6.3 per 100 000 person-years, respectively (difference between groups, P < 0.01). Cox proportional hazard adjustment showed the HR for bullous pemphigoid in dialysis patients was 2.12 (95% confidence interval [CI] 1.64-2.74, P < 0.0001) compared with the control group. Dialysis patients aged <75 years had an even higher risk of bullous pemphigoid development (5- to 8-fold) than the control group. The adjusted HR for pemphigus was not elevated in dialysis patients (adjusted HR 1.52, 95% CI 0.87-2.67, P = 0.14). Chronic dialysis is an independent risk factor for developing bullous pemphigoid, but not a risk factor for pemphigus. Physicians should be aware of the predisposition of chronic dialysis patients to bullous pemphigoid.

Case Report: Localized bullous pemphigoid induced by local triggers: a case series and a proposal for diagnostic criteria based on a literature review

Introduction

Localized bullous pemphigoid (LBP) is an infrequent bullous pemphigoid (BP) variant restricted to a body region. According to the most compelling evidence, LBP occurs in patients with pre-existent serum antibodies against the basement membrane zone, which occasionally acquire the capacity to induce disease after the influence of different local factors acting as triggers.

Methods

We hereby present a multicenter cohort of 7 patients with LBP developed after local triggers: radiotherapy, thermal burns, surgery, rosacea, edema and a paretic leg. In addition, we conducted a review of the literature, and we propose a set of diagnostic criteria for LBP, also based on our case series and the 2022 BP guidelines from the European Academy of Dermatology and Venereology.

Results

During follow-up, three of the patients from our series evolved to a generalized BP, with only one requiring hospitalization. Our literature search retrieved 47 articles including a total of 108 patients with LBP, with a 63% with a potential local precipitating factor previous to their diagnosis. LBP mostly affected older females, and a subsequent generalized progression occurred in 16.7% of the cases. The most frequently involved areas were the lower limbs. Radiation therapy and surgery were responsible for the inducement of nearly 2 in 3 cases of LBP. We observed a significantly higher risk of generalization in cases where the trigger led to the developing of LBP earlier (p=0.016). Our statistical analysis did not detect any other prognosis factor for generalization when assessing direct immunofluorescence, histological and serological results, or other patient related factors.

Conclusion

LBP should be suspected in patients with recurrent localized bullous eruptions. The presence of a trauma history in the same anatomic area is reported in most cases.

Necrotizing Fasciitis-Severe Complication of Bullous Pemphigoid: A Systematic Review, Risk Factors, and Treatment Challenges

Background and objectives: Bullous pemphigoid (BP), the most common subepidermal autoimmune skin blistering disease (AIBD) has an estimated annual incidence of 2.4 to 42.8 new cases per million in different populations, designating it an orphan disease. Characterized by disruption of the skin barrier combined with therapy-induced immunosuppression, BP could pose a risk for skin and soft tissue infections (SSTI). Necrotizing fasciitis (NF) is a rare necrotizing skin and soft tissue infection, with a prevalence of 0.40 cases per 100,000 to 15.5 cases per 100,000 population, often associated with immunosuppression. Low incidences of NF and BP classify them both as rare diseases, possibly contributing to the false inability of making a significant correlation between the two. Here, we present a systematic review of the existing literature related to the ways these two diseases correlate. Materials and methods: This systematic review was conducted according to the PRISMA guidelines. The literature review was conducted using PubMed (MEDLINE), Google Scholar, and SCOPUS databases. The primary outcome was prevalence of NF in BP patients, while the secondary outcome was prevalence and mortality of SSTI in BP patients. Due to the scarcity of data, case reports were also included. Results: A total of 13 studies were included, six case reports of BP complicated by NF with six retrospective studies and one randomized multicenter trial of SSTIs in BP patients. Conclusions: Loss of skin integrity, immunosuppressive therapy, and comorbidities commonly related to BP patients are risk factors for necrotizing fasciitis. Evidence of their significant correlation is emerging, and further studies are deemed necessary for the development of BP-specific diagnostic and treatment protocols.

Interleukin-36 cytokines are overexpressed in the skin and sera of patients with bullous pemphigoid

Bullous pemphigoid (BP) is an autoimmune bullous disease, characterized by autoantibodies targeting BP180 and BP230. The role of interleukin (IL)-36, a potent chemoattractant for granulocytes, in BP remains elusive.The expression of IL-36 cytokines (IL-36α, β, γ) and their antagonists (IL-36Ra and IL-38) was analysed in the skin and serum samples of patients with BP (n = 31), psoriasis (n = 10) and healthy controls (HC) (n = 14) by quantitative polymerase chain reaction and enzyme linked immunosorbent assay, respectively. Skin and serum levels of all cytokines were correlated with the Bullous Pemphigoid Disease Area Index (BPDAI) score and with the serum concentration of pathogenic antibodies.IL-36α, IL-36β, IL-36γ and IL-36Ra were significantly (p < 0.05) overexpressed in BP skin compared to HC, without remarkable differences relative to psoriasis skin. The expression of IL-38 was significantly (p < 0.05) higher in BP compared to psoriasis skin.IL-36α and γ, but not β, serum concentrations were significantly (p < 0.05) higher in BP compared to HC. IL-36γ was significantly (p < 0.05) more expressed in the serum of psoriasis patients than BP. The serum concentration of IL-36Ra and IL-38 were similar between BP and HC, while IL-38 serum levels were significantly (p < 0.05) higher in BP compared to psoriasis patients. Serum IL-36α correlated significantly with BPDAI (r = 0.5 p = 0.001).IL-36 agonists are increased in BP patients, both locally and systemically. Serum IL-36α might represent a potential biomarker for BP. An inefficient balance between IL-36 agonists and antagonists is likely to occur during BP inflammation.

The Intriguing Links between Psoriasis and Bullous Pemphigoid

The coexistence of psoriasis with autoimmune bullous diseases (AIBDs), particularly bullous pemphigoid (BP), has been documented in case reports and series, as well as in epidemiological studies. The onset of psoriasis precedes that of BP in the majority of cases. Patients with concomitant BP and psoriasis are generally younger at the onset of BP and present with fewer erosions and blisters as compared with patients suffering from isolated BP. Intriguingly, it has been speculated that some BP cases with comorbid psoriasis can actually correspond to anti-laminin gamma-1 pemphigoid, a rare form that was recently recognized as a distinct entity and which can mimic BP and/or other subepidermal AIBDs. The pathomechanisms underlying the BP-psoriasis association have not yet been identified, although several hypotheses have been proposed. The most credited among such hypotheses involves the so-called "epitope spreading" phenomenon, with tissue injury secondary to a primary inflammatory process (i.e., psoriasis) leading to the exposure of sequestered antigens evoking a secondary autoimmune disease (i.e., bullous pemphigoid). This narrative review aims to give a brief overview of the association between psoriasis and BP, examining epidemiological, clinical, and immunopathological features, the pathomechanisms underlying this association, the treatments for psoriasis incriminated as potential triggers of BP, and the therapeutic management of patients with psoriasis and BP.

Case Report: Bullous Pemphigoid Associated With Morphea and Lichen Sclerosus: Coincidental Diseases or Pathogenetic Association?

Bullous pemphigoid (BP) represents the most common autoimmune bullous disease and is characterized by IgG autoantibodies targeting collagen XVII (BP180). BP has reportedly been occurred in association with other inflammatory skin diseases. Here, we describe the unusual occurrence of BP in a female patient with a concomitant history of generalized morphea (localized scleroderma, LoS) and cutaneous and genital lichen sclerosus (LiS). The occurrence of BP was associated with elevated serum levels of anti-BP180 IgG autoantibodies, which decreased upon clinical remission. Autoimmune bullous diseases and sclerosing dermatitis are immunologically distinct entities, whose association has been rarely described. In this study, we provide a literature review on cases of BP developed in patients with either LoS or LiS. Further, we discussed immunological mechanisms which may have favored the emergence of BP in our patient.

Bullous Pemphigoid Associated With COVID-19 Vaccines: An Italian Multicentre Study

Bullous pemphigoid (BP) is an autoimmune bullous disease caused by circulating autoantibodies toward the hemidesmosomal antigens BP180 and BP230. Cases of BP have been described following vaccinations against tetanus, poliomyelitis, diphtheria, influenza, pneumococcus, meningococcus, hepatitis B and rabies. The putative mechanism by which COVID-19-vaccines may induce BP has not been clarified. An Italian multicentre study was conducted to collect clinical, histopathological and immunopathological data of patients with BP associated with COVID-19-vaccines. Twenty-one cases were collected, including 9 females and 12 males (M/F = 1.3) with a median age at diagnosis of 82 years. Seventeen patients received the COMIRNATY Pfizer-BioNTech vaccine, two the Moderna mRNA-1273 vaccine, one the ChAdOx1/nCoV-19-AstraZeneca/ Vaxzevria vaccine and one received the first dose with the ChAdOx1/nCoV-19-AstraZeneca/Vaxzevria vaccine and the second dose with the COMIRNATY Pfizer-BioNTech vaccine. Median latency time between the first dose of anti-SARS-CoV-2 vaccine and the onset of cutaneous manifestations was 27 days. Median BPDAI at onset was 42. Eleven out of seventeen patients (65%) had positive titres for anti-BP180 antibodies with a median value of 106.3 U/mL on ELISA; in contrast, only five out of seventeen (29%) were positive for anti-BP230 antibodies, with a median of 35.3 U/mL. In conclusion, in terms of mean age, disease severity at diagnosis and clinical phenotype vaccine-associated BP patients seem to be similar to idiopathic BP with an overall benign course with appropriate treatment. On the other hand, the slight male predominance and the reduced humoral response to BP230 represent peculiar features of this subset of patients.

Bullous pemphigoid: An immune disorder related to aging (Review)

Bullous pemphigoid (BP) is the most frequent subepidermal autoimmune blistering disease and is caused by autoantibodies directed against two principal antigens of the hemidesmosome, BP antigen 180 and BP antigen 230. The pathogenesis of BP is dependent upon the interaction between genetic predisposition, physiological skin alterations due to aging and specific triggers. Several triggers have already been reported to induce this disease and include drugs, thermal or electrical burns, surgical procedures, trauma, UV radiation, radiotherapy, chemicals and infections. Data from the current literature support the hypothesis that alterations of the skin barrier associated with aging increase individual susceptibility to these aforementioned triggers. Consequently, this has been reported to lead to the attack of autoantibodies, demonstrating the predilection of BP for the elderly population. The identification of triggering factors and comorbidities may aid in understanding the pathogenesis of BP and improve clinical management by encouraging their prompt recognition and removal. Moreover, the present review has indicated that current management of BP should be aimed at counteracting the detrimental effects of aging on the skin by restoring skin barrier integrity and maintaining cutaneous homeostasis, for example with systematic applications of topical emollients and photoprotection. This strategy could prove even more beneficial in the elderly, in which frequent comorbidities associated with age often narrow available immunosuppressive treatment options. Furthermore, the safety of treatment regimens may significantly affect outcome and prognosis.

Prevalence and presumptive triggers of localized bullous pemphigoid

Bullous pemphigoid (BP) is an autoimmune skin disease, caused by autoantibodies to BP180 and/or BP230. While both these autoantigens are expressed in the entire skin, only some parts of the body become affected. Rare clinical observations indicate that BP may also manifest locally, usually following exposure to triggers. Here, we evaluated the occurrence and potential triggers of localized BP (LBP) in a cohort of 285 BP patients. Medical records of all BP patients hospitalized between 2009 and 2019 were reviewed. In 7/285 BP patients, a localized variant was identified. In 5/7 LBP patients, the disease remained local, while in 2/7 patients, an initial LBP subsequently spread. All cases were preceded by presumptive triggers, including previously described triggers and bacterial infections. Overall, LBP is rare. LBP, however, might be underdiagnosed and should thus be considered in the differential diagnosis, particularly when trigger factors preceded.

Bullous pemphigoid in patients receiving peritoneal dialysis: a case series and a literature survey

Bullous pemphigoid (BP) is an autoimmune subepidermal blistering disease. Although several cases of BP in end-stage renal disease patients receiving peritoneal dialysis (PD) or hemodialysis have been reported, the incidence of BP in these patients remains unknown. We recently experienced three PD patients diagnosed with BP. The skin injury was likely to be a trigger of BP in all the three PD patients. Nifedipine and icodextrin exposures were possible factors directly or indirectly affecting the onset of BP, because they were common in the three cases. We also report that the incidence of BP in PD patients was 3/478.3 person-years in a single-center 10-year study. This case series with a literature survey describes that the skin and tissue injuries are potential triggers responsible for the onset of BP in dialysis patients and that the incidence of BP in these patients seems to be much higher than that in the general population.

Bullous Pemphigoid: Trigger and Predisposing Factors

Bullous pemphigoid (BP) is the most frequent autoimmune subepidermal blistering disease provoked by autoantibodies directed against two hemidesmosomal proteins: BP180 and BP230. Its pathogenesis depends on the interaction between predisposing factors, such as human leukocyte antigen (HLA) genes, comorbidities, aging, and trigger factors. Several trigger factors, such as drugs, thermal or electrical burns, surgical procedures, trauma, ultraviolet irradiation, radiotherapy, chemical preparations, transplants, and infections may induce or exacerbate BP disease. Identification of predisposing and trigger factors can increase the understanding of BP pathogenesis. Furthermore, an accurate anamnesis focused on the recognition of a possible trigger factor can improve prognosis by promptly removing it.

Bullous pemphigoid development during the course of breast cancer: a radiation induced or a radiation recall dermatitis?

Background:

Bullous pemphigoid (BP) is the most common autoimmune bullous disease, which is usually seen in older ages. Rarely, radiotherapy (RT) has been reported as a localised trigger factor for BP.

Case:

We present a case of a 64-year-old woman who underwent radical mastectomy and radiation therapy for breast cancer. Two months after the completion of RT with adjuvant Trastuzumab, a BP eruption developed in the irradiated area, spreading thereafter to other skin areas. The patient was treated with oral corticosteroids and the lesions evolved favourably.

Conclusion:

This case demonstrates a relatively benign skin reaction that could develop during the course of cancer treatment, which required co-management by oncologists, pathologists and dermatologists.

Nickel and Skin: From Allergy to Autoimmunity

Introduction & Objectives:

Cutaneous and systemic reactions to various metal implants and medical devices have been well documented. The aim of this review was to focus on the probable common mechanisms of allergy and autoimmunity that may lead to similar clinical outcomes following the growing evidence in the literature of metal and nickel-related systemic, autoimmune or autoinflammatory disorders.

Methods:

Detailed search of the available electronic databases (PubMed-Medline) was conducted for review of the literature on that topic till the present moment.

Results:

Multiple reports on the immunological effects of metals including immunomodulation, allergy, or autoimmunity were identified. It was found that metals may act through immunosuppression, immunotoxicity, or as immune adjuvants thus provoking allergy and autoimmunity in susceptible individuals. Both external or internal exposure to metals was observed. Nickel has been identified as the most common sensitizer, and also the most studied one. The coexistence of both allergic and autoimmune symptoms, induced by nickel, has been published, suggesting the autoimmune potential of nickel compounds.

Conclusions:

Clinical experience and scientific literature together demonstrate that metals may play an important role in the development of autoimmune diseases. While metal implant allergies and complications are on the rise, they remain a diagnostic and therapeutic challenge. Elucidation of their possible mechanisms will contribute to the more successful and safer treatment of affected individuals.

Epidermal Damage Induces Th1 Polarization and Defines the Site of Inflammation in Murine Epidermolysis Bullosa Acquisita

Epidermolysis bullosa acquisita is an autoimmune skin disease characterized by subepidermal blisters. The pathogenesis is mediated by deposits of autoantibodies directed against type VII collagen in the skin, but the sequence of events regulating the localization of skin blisters is not fully understood. In this study, using the immunization-induced mouse model of epidermolysis bullosa acquisita, we demonstrate that epidermal disruption induces not only an infiltration of CD4⁺ T cells but also a T helper type 1 phenotype as it has been described for delayed-type hypersensitivity reactions. This T helper type 1 reaction was not found when different antigens were applied. Deep T-cell receptor β profiling revealed shifts in the V/J gene usage only in epidermolysis bullosa acquisita, suggesting an infiltration of autoantigen-specific T cells. To target these autoantigen-specific T cells, we established an approach with which skin inflammation could be prevented without impairing the functionality of autoantibodies. We conclude that T-cell involvement in skin blistering diseases such as epidermolysis bullosa acquisita relates not only to T-cell help for B cells that produce pathogenic autoantibodies but also to autoreactive T helper type 1 effector cells that migrate into injured skin sites, exacerbate inflammation through production of inflammatory cytokines such as IFNγ, and prevent wound healing.

Dipeptidyl peptidase-4 inhibitor-associated bullous pemphigoid, likely triggered by scabies, in a hemodialysis patient with human leukocyte antigen-DQB1*03:01

Bullous pemphigoid (BP) is the most common autoimmune subepidermal bullous diseases. Autoantibodies against hemidesmosomal adhesion proteins might be involved in the developing process. BP usually affects the elderly with high mortality whereas the drug-induced BP is often improved and rarely relapses after the withdrawal of the suspected drug. An accumulated evidence suggests that dipeptidyl peptidase-4 inhibitor (DPP-4I), which has been widely used as the antidiabetic drug improves glycemic control with little risk for hypoglycemia, could be an inducer of DPP-4I-associated BP (DPP-4I-BP). While the precise mechanism remains unclear, a unique immunological profile with human leukocyte antigen (HLA)-DQB1*03:01 could be a biomarker of genetic susceptibility to DPP-4I-BP. Here, we encountered an interesting case of DPP-4I-BP with HLA-DQB1*03:01, which was likely triggered by scabies. A 56-year-old Japanese male with type 2 diabetes on hemodialysis was referred to our hospital due to worsened blisters. Prior to his admission, he had been on linagliptin, a DPP-4I, for 5 months. He then suffered from scabies 2 weeks before his admission while the treatment with ivermectin failed to improve his symptom. Based on his clinical symptom, positive for anti-BP180 autoantibody in serum, and the pathological alterations of skin biopsy specimens, he was diagnosed with DPP-4I-BP. Importantly, he also carried an HLA-DQB1*03:01 allele. Oral prednisolone was subsequently administered after the discontinuation of linagliptin, and his symptom gradually disappeared. Given the fact that the DPP-4I-BP could be a life-threating disease, we should be cautious of prescribing DPP-4I in hemodialysis patients, whose immune system could be impaired.

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.

Anti-BP180 Autoantibodies Are Present in Stroke and Recognize Human Cutaneous BP180 and BP180-NC16A

Objective: Current evidence has revealed a significant association between bullous pemphigoid (BP) and neurological diseases (ND), including stroke, but the incidence of BP autoantibodies in patients with stroke has not previously been investigated. Our study aimed to assess BP antigen-specific antibodies in stroke patients. Design: One hundred patients with stroke and 100 matched healthy controls were randomly selected for measurement of anti-BP180/BP230 IgG autoantibodies by enzyme-linked immunosorbent assay (ELISA), salt-split indirect immunofluorescence (IIF), and immunoblotting against human cutaneous BP180 and BP180-NC16A. Results: Anti-BP180 autoantibodies were found in 14 (14.0%) patients with stroke and 5 (5.0%) of controls by ELISA (p < 0.05). Sera from 13 (13.0%) patients with stroke and 3 (3.0%) controls reacted with 180-kDa proteins from human epidermal extract (p < 0.05). 11 (11.0%) of stroke and 2 (2.0%) of control sera recognized the human recombinant full length BP180 and NC16A (p < 0.05). The anti-BP180-positive patients were significantly younger than the negative patients at the time of stroke (p < 0.001). Conclusion: Development of anti-BP180 autoantibodies occurs at a higher frequency after stroke, suggesting BP180 as a relatively common autoantigen after stroke and providing novel insights into BP pathogenesis in aging.

Dermatitis Herpetiformis and Celiac Disease Increase the Risk of Bullous Pemphigoid

Bullous pemphigoid (BP) and dermatitis herpetiformis (DH) are autoimmune bullous skin diseases. DH has been described to evolve into BP and the two diseases can have overlapping clinical appearances and diagnostic findings, but the association between DH and BP has not previously been studied in a large population. To evaluate DH and celiac disease as risk factors for BP, we conducted a retrospective case-control study of patients with BP and matched controls with basal cell carcinoma diagnosed in Finland between 1997 and 2013. A total of 3,397 patients with BP and 12,941 controls were included in the study. Forty-one (1.2%) BP patients and 7 (0.1%) controls had preceding DH. Diagnosed DH increased the risk of BP 22-fold (odds ratio = 22.30; 95% confidence interval = 9.99-49.70) and celiac disease 2-fold (odds ratio = 2.54; 95% confidence interval = 1.64-3.92) compared to controls. Eighteen (43.9%) of the patients who had DH and subsequent BP had bought dapsone during the 2 years prior to their BP diagnosis. Mean time between diagnosed DH and BP was 3 years. We conclude that diagnosis of DH is associated with a striking increase in the risk for BP.

Biological predictors shared by dementia and bullous pemphigoid patients point out a cross-antigenicity between BP180/BP230 brain and skin isoforms

Bullous pemphigoid (BP) following dementia diagnosis has been reported in the elderly. Skin and brain tissues express BP180 and BP230 isoforms. Dementia has been associated with rs6265 (Val66Met) polymorphism of the brain-derived neurotrophic factor (BDNF) gene and low serum BDNF. Here we investigated a possible cross-antigenicity between BP180/BP230 brain and skin isoforms. We assessed antibodies against BP180/BP230 and BDNF levels by ELISA and BDNF Val66Met SNP by PCR in three groups: 50 BP patients, 50 patients with dementia, and 50 elderly controls. Heatmap hierarchical clustering and data mining decision tree were used to analyze the patients' demographic and laboratorial data as predictors of dementia-BP association. Sixteen percent of BP patients with the lowest serological BDNF presented dementia-BP clinical association. Anti-BP180/230 positivity was unexpected observed among dementia patients (10%, 10%) and controls (14%, 1%). Indirect immunofluorescence using healthy human skin showed a BP pattern in two of 10 samples containing antibodies against BP180/BP230 obtained from dementia group but not in the control samples. Neither allelic nor genotypic BDNF Val66Met SNP was associated with dementia or with BP (associated or not with clinical manifestation of dementia). Heatmap analysis was able to differentiate the three studied groups and confirmed the ELISA results. The comprehensive data mining analysis revealed that BP patients and dementia patients shared biological predictors that justified the dementia-BP association. Autoantibodies against the BP180/BP230 brain isoforms produced by dementia patients could cross-react with the BP180/BP230 skin isoforms, which could justify cases of dementia preceding the BP disease.

Bullous pemphigoid induced by Hijama therapy (cupping)

Bullous pemphigoid (BP) is described as a subepidermal blistering disorder, which is commonly reported among the elderly, particularly those older than 60 years of age. In this report, we present the case of a 41-year-old female patient with BP lesions that were initially detected at the site of Hijama therapy with a subsequent generalized spread. Punch biopsy from the lesions and perilesional direct immunofluorescence (DIF) demonstrated features of BP. The anti-BP180 level was 178 RU/mL, and the anti-BP230 level was negative. BP antigens at the site of Hijama caused an antibody response, which led to widespread blistering over the trunk due to epitope spreading. In a comprehensive review of the literature, a total of 22 BP patients with lesions due to physical trauma were studied, and clinical, immunological, and epidemiological information was gathered. This article is the first report on the occurrence of BP induced by Hijama therapy.

Bullous Pemphigoid Triggered by Thermal Burn Under Medication With a Dipeptidyl Peptidase-IV Inhibitor: A Case Report and Review of the Literature

Bullous pemphigoid (BP) is a common autoimmune blistering disease in which autoantibodies mainly target the hemidesmosomal component BP180 (also known as type XVII collagen) in basal keratinocytes. Various triggering factors are known to induce BP onset, including radiotherapy, burns, ultraviolet exposure, surgery, and the use of dipeptidyl peptidase-IV inhibitors (DPP4i), which are widely used antihyperglycemic drugs. Here, we present a case of BP triggered by a thermal burn under medication with DPP4i. A 60-year-old man with type II diabetes had been treated with the DPP4i linagliptin for 1 year. After the right forearm experienced a thermal burn, blisters developed around the burned area and gradually spread over the whole body with the production of autoantibodies targeting the non-NC16A domain of BP180. The diagnosis of BP was confirmed by immunohistopathological examination. Upon withdrawal of linagliptin and treatment with topical steroid and minocycline, complete remission was achieved after 4 months. Previously, 13 cases of BP that developed after thermal burns have been reported, and our case shared some of the clinical features of these thermal burn-induced BP cases. Interestingly, the present case also showed the typical clinical, histopathological, and immunological features of the non-inflammatory type of DPP4i-associated BP (DPP4i-BP). Although the pathogenesis of BP remains uncertain, the present case suggests that DPP4i may trigger the onset of BP similarly to a thermal burn. In addition, the clinical and histopathological features of DPP4i-BP may be distinct from other types of BP.

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

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

Localized Bullous Pemphigoid on the Site of Knee Arthroplasty: A Case Report

Localized bullous pemphigoid is a rare variant of bullous pemphigoid, and its exact etiopathogenesis is yet to be elucidated. We present a case of a 74-year-old Caucasian male with a 3-month history of skin lesions that appeared 9 months after he underwent a knee arthroplasty. Dermatological examination showed several pruritic tense bullae on the right knee, localized around the surgical scar, as well as erosions covered with crusts. The diagnosis of localized bullous pemphigoid was confirmed by direct immunofluorescence test (conventional and split-skin). The patient was treated with potent topical steroids, which led to complete resolution of cutaneous lesions.

We suppose that the occurrence of localized bullous pemphigoid in our patient may be explained by the concept of “immunocompromised district” in which one disease (surgery) caused an immunological alteration which is a predisposing factor for the development of secondary disease such as localized bullous pemphigoid.

Development of bullous pemphigoid during the haemodialysis of a young man: case report and literature survey

Haemodialysis is the most frequent form of renal replacement therapy (RRT) in patients with end-stage renal disorder (ESRD). Patients with ESRD frequently develop skin problems, mainly xerosis, pruritus and hyperpigmentation, as well as bullous diseases, mainly porphyria or pseudoporphyria and, in some cases, bullous pemphigoid (BP). BP is the most common autoimmune sub-epidermal blistering disease, and it predominantly affects elderly people. Clinically, BP is characterised by generalised pruritic, bullous eruptions and urticaria-like lesions. Usually, BP is an idiopathic disorder; however, in some cases, underlying internal disorders are present, like diabetes or neurological disorders. Herein, we present a 33-year-old man with ESRD, maintained on haemodialysis, who developed BP. There are only six cases with BP provoked by the placement of a fistula for haemodialysis. BP in the current patient was confirmed by direct immunofluorescence (DIF) and indirect immunofluorescence using BIOCHIP. The patient responded promptly to tertracycline and 0·05% clobetasol propionate lesionally. However, the relationship between BP and the fistula for haemodialisys still remains unknown. It is highly likely that the skin injury associated with fistula placement was responsible for the alteration of the basement membrane zone (BMZ) and the stimulation of the immune system, leading to BP development. To explain the real role of fistula placement as a provocative factor in BP, other such cases are required for assessment.