Association Between Medication Use and Bullous Pemphigoid: A Systematic Review and Meta-analysis

A Retrospective Comparison of Diagnostic Tools of Bullous Pemphigoid for Elderly Patients

BACKGROUND

Older patients who are predisposed to bullous pemphigoid (BP) may exhibit reluctance to undergo skin biopsy due to potential complications.

OBJECTIVES

This study aimed to conduct a comparative evaluation among histology, direct immunofluorescence (DIF), and indirect immunofluorescence (IIF) to determine the optimal diagnostic tool in elderly patients.

METHODS

A retrospective study was conducted on 841 patients suspected of having BP. All cases were initially classified as BP and non-BP in accordance with the diagnostic criteria. Student's t-test and chi-squared test examined differences between the 2 groups. We evaluated the sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio detected by the 3 tools. We stratified the analysis by age to compare the performance of the diagnostic tools and examined the risk factors associated with BP using logistic regression.

RESULTS

Overall, histology exhibited the highest sensitivity (89.4%), while DIF demonstrated the highest specificity (67.1%). In the elderly, the IIF test exhibited the highest specificity (57.5%), the highest positive likelihood ratio (2.047), and the lowest negative likelihood ratio (0.226). Among patients taking Dipeptidyl Peptidase-4 (DPP-4) inhibitors, IIF demonstrated the highest positive likelihood ratio (3.194) and the second-lowest negative likelihood ratio (0.235).

CONCLUSIONS

In cases that elderly patients suspected of having BP are reluctant to undergo skin biopsy, IIF demonstrates the optimal diagnostic method due to its highest positive likelihood ratio, the lowest negative likelihood ratio among the 3 diagnostic measures. Moreover, IIF is found to be a more effective tool for detecting BP in patients using DPP-4 inhibitors.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Bullous Pemphigoid Associated With the Use of Sacubitril/Valsartan: A Case Report and Literature Review

 Bullous pemphigoid (BP) is a complex autoimmune blistering disease with an increased incidence in the comorbid population, particularly among older adults. The occurrence of drug-induced BP is associated with an underlying genetic predisposition, triggering an enhanced immune response, the formation of autoantibodies, and alterations in antigenic properties within the basement membrane zone. With over 90 identified drugs capable of precipitating BP, we present the case of an 87-year-old woman with comorbidities who experienced a medication change from losartan to sacubitril/valsartan. Three months later, erythematous lesions appeared on her lower limbs, progressing to a generalized rash accompanied by itching. Over the following month, these lesions evolved into tense blisters with serous content and intense pain. Suspecting the medication switch to sacubitril/valsartan as the cause, the drug was discontinued, and immunomodulatory treatment was initiated, resulting in a notable improvement in the lesions.

Assoziation zwischen chronischer Nierenerkrankung und dem Risiko für bullöses Pemphigoid: eine nationale bevölkerungsbasierte Kohortenstudie

Hintergrund

Studien haben gezeigt, dass das bullöse Pemphigoid (BP) auch bei Patienten mit chronischer Nierenerkrankung (CKD, chronic kidney disease) auftritt. Unklar ist, wie hoch das BP‐Risiko bei CKD‐Patienten ist.

Zielsetzung

Es sollte untersucht werden, ob eine CKD das BP‐Risiko erhöht.

Methodik

Die Studienteilnehmer wurden für den Zeitraum von 2007 bis 2018 aus der nationalen Datenbank der taiwanesischen Krankenversicherung rekrutiert. Insgesamt wurden 637 664 neu diagnostizierte Patienten mit CKD sowie 637 664 nach Alter, Geschlecht und Komorbidität übereinstimmende Kontrollpersonen ohne CKD in die Untersuchung aufgenommen. Zur Bewertung des BP‐Risikos kam ein Modell für konkurrierende Risiken zum Einsatz.

Ergebnisse

Nach Adjustierung für Alter, Geschlecht und Komorbidität im multivariaten Modell zeigte sich die CKD als signifikanter Risikofaktor für BP (adjustierte Hazard Ratio [aHR]: 1,29; 95%‐Konfidenzintervall [KI]: 1,17–1,42; p < 0,001). CKD‐Patienten wurden in die Gruppen dialysepflichtig und nicht‐dialysepflichtig unterteilt und mit den Patienten ohne CKD verglichen. Es zeigte sich, dass dialysepflichtige CKD‐Patienten das höchste BP‐Risiko aufwiesen (aHR 1,75; 95%‐KI 1,51–2,03), gefolgt von nicht‐dialysepflichtigen CKD‐Patienten (aHR 1,20; 95%‐KI 1,08–1,32).

Limitationen

Detaillierte Laborbefunde zur Einschätzung des CKD‐Schweregrads fehlten.

Schlussfolgerungen

Im Vergleich zu Personen ohne CKD hatten Patienten mit CKD ein 1,3‐fach erhöhtes BP‐Risiko. Bei Patienten mit dialysepflichtiger CKD war das Risiko 1,8‐fach erhöht.

Association between chronic kidney disease and risk of bullous pemphigoid: a nationwide population-based cohort study

BACKGROUND

Studies have shown that bullous pemphigoid (BP) occurs in patients with chronic kidney disease (CKD). However, the risk of developing BP in patients with CKD remains inconclusive.

OBJECTIVE

To investigate whether CKD increases the risk of BP.

METHODS

Participants were recruited from the National Health Insurance Database of Taiwan between 2007 and 2018. Overall, 637,664 newly diagnosed patients with CKD and 637,664 age-, sex-, and comorbidity-matched non-CKD participants were selected. A competing risk model was used to evaluate the risk of development of BP.

RESULTS

After adjusting for age, sex, and comorbid diseases in the multivariate model, CKD was a significant risk factor for BP (adjusted hazard ratio [aHR]: 1.29; 95% confidence interval [CI]: 1.17-1.42; p < 0.001). CKD patients were classified into the dialytic or non-dialytic groups and compared to non-CKD participants, and this revealed that patients with dialysis-dependent CKD had the highest risk of BP (aHR 1.75; 95% CI 1.51-2.03), followed by patients with non-dialysis-dependent CKD (aHR 1.20; 95% CI 1.08-1.32).

LIMITATIONS

We lacked detailed laboratory data on the severity of CKD.

CONCLUSIONS

Compared with individuals without CKD, those with CKD had a 1.3-fold increased risk of BP. Patients with dialysis-dependent CKD had an even higher BP risk (1.8-fold).

Accurate diagnosis of bullous pemphigoid requires multiple health care visits

Introduction

Accurate use of diagnostic codes is crucial for epidemiological and genetic research based on electronic health record (EHR) data.

Methods

This retrospective study validated the International Classification of Diseases (ICD)-10 diagnostic code L12.0 for bullous pemphigoid (BP) using EHR data from two Finnish university hospitals. We found 1225 subjects with at least one EHR entry of L12.0 between 2009 and 2019. BP diagnosis was based on clinical findings characteristic of BP and positive findings on direct immunofluorescence (DIF), BP180-NC16A enzyme-linked immunosorbent assay (ELISA) or indirect immunofluorescence (IIF) assay.

Results

True BP was found in 901 patients; the positive predictive value (PPV) for L12.0 was 73.6% (95% CI 71.0-76.0). L12.0 was more accurately registered in dermatology units than any specialized health care units (p<0.001). Including patients with multiple L12.0 registrations (≥3), increased the accuracy of the L12.0 code in both dermatology units and other settings.

Discussion

One diagnostic code of L12.0 is not enough to recognize BP in a large epidemiological data set; including only L12.0 registered in dermatology units and excluding cases with <3 L12.0 record entries markedly increases the PPV of BP diagnosis.

From Molecular Insights to Clinical Perspectives in Drug-Associated Bullous Pemphigoid

Bullous pemphigoid (BP), the most common autoimmune blistering disease, is characterized by the presence of autoantibodies targeting BP180 and BP230 in the basement membrane zone. This leads to the activation of complement-dependent and independent pathways, resulting in proteolytic cleavage at the dermoepidermal junction and an eosinophilic inflammatory response. While numerous drugs have been associated with BP in the literature, causality and pathogenic mechanisms remain elusive in most cases. Dipeptidyl peptidase 4 inhibitors (DPP4i), in particular, are the most frequently reported drugs related to BP and, therefore, have been extensively investigated. They can potentially trigger BP through the impaired proteolytic degradation of BP180, combined with immune dysregulation. DPP4i-associated BP can be categorized into true drug-induced BP and drug-triggered BP, with the latter resembling classic BP. Antineoplastic immunotherapy is increasingly associated with BP, with both B and T cells involved. Other drugs, including biologics, diuretics and cardiovascular and neuropsychiatric agents, present weaker evidence and poorly understood pathogenic mechanisms. Further research is needed due to the growing incidence of BP and the increasing identification of new potential triggers.

Prevalence of diabetes mellitus in bullous pemphigoid patients in the absence of dipeptidyl peptidase-4 inhibitors: a systematic review and meta-analysis

Bullous pemphigoid (BP) has been associated with dipeptidyl peptidase-4 inhibitor (DDP-4i) use in patients with diabetes mellitus (DM). The prevalence and association of DM in BP patients independent of DPP-4i use has not been investigated by meta-analysis. To perform a systematic review and meta-analysis on the association between diabetes and bullous pemphigoid. The goal was to determine the prevalence and pooled odds ratio of BP patients with DM in the absence of DDP-4i use compared to the general population prevalence of diabetes mellitus. OVID Medline, EMBASE, Cochrane Central and Web of Science were searched for relevant studies published from inception to April 2020. Case-control, case-series, cohort, and cross-sectional studies that included the association of BP and DM without DDP-4i's, in any language. PRISMA guidelines were followed for data extraction and the Newcastle-Ottawa Scale for risk of bias evaluation. Three reviewers independently performed data extraction. Pooled odds ratio and prevalence were calculated using the random effects model. The odds ratio and prevalence of BP patients with DM. Overall, 8 studies out of 856 identified publications through data base searches were included. The pooled prevalence of diabetes in patients with BP was 20.0% [95% CI 14%-26%; p = 0.00]. Within the comparative non-BP control population, 13% had diabetes. BP patients were more likely to have diabetes compared to a control population without BP [OR 2.10, 95% CI 1.22-3.60; p = 0.01]. This study found that twice the number of BP patients have DM (20%) compared to the general population reported as 10.5%, warranting monitoring of blood glucose levels in BP patients who may have yet undeclared or undiagnosed DM when initiating systemic steroids.

The effect of dipeptidyl peptidase-4 inhibitor on incidence and clinical course in bullous pemphigoid patients in a tertiary medical center

Several studies have reported an association between dipeptidyl peptidase 4 inhibitor (DPP4i), a commonly prescribed second-line oral antihyperglycemic drug, and bullous pemphigoid (BP). However, the benefits of DPP4i withdrawal in patients with BP remain controversial. This study primarily aimed to evaluate the clinical severity of DPP4i-associated BP by comparing it to those without Type 2 diabetes mellitus (DM). The secondary objective was to determine whether cessation of DPP4i is necessary for all patients with BP. This retrospective case-control study included 83 patients. The participants were divided into three groups according to their diabetic status and the status of discontinuance or continuance of DPP4i. The 12-month follow-up of the monthly dosage of systemic steroids per body weight (kg) and the percentage of systemic steroid off-therapy in these participants were recorded since the diagnosis of BP. Compared to patients with BP without DM, the 1st, 3rd, and 12th systemic prednisolone doses were significantly lower in the DPP4i group (p = 0.01684, 0.02559, and 0.009336, respectively). The 12th systemic prednisolone dose was significantly lower in patients who discontinued DPP4i (p = 0.0338). Nevertheless, several spontaneous remissions with systemic steroid off-therapy were also noted in the DPP4i-continuance group within 12 months of follow-up. This article supports the favorable impact of DPP4i withdrawal in patients with BP and shows that DPP4i may incite or aggravate BP, resulting in a milder disease course.

[Pemphigoid diseases in older adults]

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

Targeting type 2 inflammation in bullous pemphigoid: current and emerging therapeutic approaches

Bullous pemphigoid (BP) is one of the most common autoimmune bullous diseases and mainly affects an elderly population with multi-morbidity. Due to the frailty of many BP patients, existing treatment options are limited. The blisters associated with BP result from IgG and IgE autoantibodies binding to the central components of hemidesmosome, BP180, and BP230, stimulating a destructive inflammatory process. The known characteristic features of BP, such as intense pruritus, urticarial prodrome, peripheral eosinophilia, elevated IgE, as well as recent expanding evidence from in vitro and in vivo studies implicate type 2 inflammation as an important driver of BP pathogenesis. Type 2 inflammation is an inflammatory pathway involving a subset of CD4+ T cells that secrete IL-4, IL-5, and IL-13, IgE-secreting B cells, and granulocytes, such as eosinophils, mast cells, and basophils. It is believed that effectors in type 2 inflammation may serve as novel and effective treatment targets for BP. This review focuses on recent understandings of BP pathogenesis with a particular emphasis on the role of type 2 inflammation. We summarize current clinical evidence of using rituximab (B-cell depletion), omalizumab (anti-IgE antibody), and dupilumab (anti-IL-4/13 antibody) in the treatment of BP. The latest advances in emerging targeted therapeutic approaches for BP treatment are also discussed.

Bullous pemphigoid and dipeptidyl peptidase-4 inhibitors: evaluation of clinical course and treatment response

BACKGROUND

Dipeptidyl peptidase-4 inhibitors (DPP4is), drugs used to treat type 2 diabetes mellitus (DM2), show a significant association with bullous pemphigoid (BP) development.

OBJECTIVES

To evaluate the clinical course and development of BP among patients with DM2 treated with DPP4is.

METHODS

This retrospective cohort study included all the patients with BP and comorbid DM2 who visited Sheba Medical Center during 2015-2020.

RESULTS

Among 338 patients with BP, 153 were included in our study. In 92 patients, BP diagnosis was attributed to the use of DPP4is. The patients with DPP4i-associated BP had fewer neurological and cardiovascular comorbidities and higher blistered body surface area (BSA) at first presentation, with noticeable upper and lower limb involvement. These patients were younger and more responsive to treatment, with a greater reduction in their BSA score after 2 months of treatment.

CONCLUSIONS

The clinical features of patients with BP treated with DPP4is were initially more severe; however, during follow-up, a marked clinical improvement was noticed, especially among patients who had ceased the drug. Therefore, although withdrawal of the drug may not impose disease remission, it can alleviate the disease course and avert the need for treatment escalation.

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.

The association of high-fluoride and high-iodine combined exposure with dental fluorosis and goiter: a meta-analysis

It is controversial that high-fluoride and high-iodine combined exposure affects the prevalence of dental fluorosis and goiter. The aim of this study was to explore the potential association between high-fluoride and high-iodine combined exposure with dental fluorosis and goiter. We retrieved relevant articles from PubMed, Cochrane Library, China National Knowledge Infrastructure, Wanfang Database and China Science and Technology Journal Database (VIP). The query format was 1 # "Fluorosis" OR "Fluoride," 2 # "Iodine" OR "Iodide," and 3 # 1 AND 2. A total of 20 papers were included in this study after independent review by two investigators. Our analysis showed that high-fluoride and high-iodine biphasic exposure was significantly associated with the prevalence of goiter (OR = 4.69, 95% CI 2.82-7.80, P < 0.001). The prevalence of dental fluorosis was also significantly raised (OR = 11.71, 95% CI 7.57-18.14, P < 0.001). Sensitivity analysis suggested that combined statistics of multiple studies were reliable. For goiter, subgroup analysis revealed study province, sample size and published year as sources of heterogeneity (P < 0.001). For dental fluorosis, only sample size was the impact factor of heterogeneity. As well, funnel plot, Begg's test and Egger's test suggested there was no publication bias (P > 0.05). Overall, our study demonstrates that high-fluoride and high-iodine combined exposure is a risk factor for occurrence of dental fluorosis and goiter. The chronic of high-fluoride and high-iodine combined exposure is a significant higher risk of disease than normal.

Intravenous immunoglobulin in patients with bullous pemphigoid insufficient response to corticosteroids: Nationwide post-marketing surveillance in Japan

BACKGROUND

In Japan, intravenous immunoglobulin (IVIG) has been approved for corticosteroid-unresponsive bullous pemphigoid (BP); however, its usage, efficacy, and safety in clinical settings remain unclear.

OBJECTIVE

To elucidate IVIG efficacy, we examined the improvement in disease severity based on the Bullous Pemphigoid Disease Area Index (BPDAI).

METHODS

In this 3-year (April 2016-March 2019), prospective, post-marketing, observational surveillance study, we enrolled 379 patients (51.3 % men; mean age, 74.5 years) with corticosteroid-unresponsive BP treated with IVIG from 143 institutions in Japan (720 treatment cycles). The percentage of patients who improved by at least one severity stage or whose symptoms completely resolved based on the BPDAI score was evaluated at 15, 30, and 60-90 days.

RESULTS

The improvement rates at 15, 30, and 60-90 days after initial treatment in the 328 IVIG-naïve patients were 70.7 %, 83.5 %, and 84.3 %, respectively. The BPDAI score decreased rapidly and significantly by 15 days compared with that observed during pre-treatment. Further improvement was observed at 30 and 60-90 days. The corticosteroid dose and anti-BP180 antibody titers decreased significantly post-treatment (both, p < .001). Approximately 25 % of IVIG-naïve patients underwent multiple treatment cycles. The improvement rate at 30 days after the final dose was 88 %, and the symptoms completely resolved in 44 % of patients. The incidence of adverse drug reactions per cycle was 8.34 %; the most common reaction was transient thrombocytopenia.

CONCLUSION

Most patients showed improvement in severity and decrease in corticosteroid dose and anti-BP180 antibody levels post-treatment, indicating that IVIG is useful for corticosteroid-unresponsive BP treatment.

Researching trends in pemphigoid diseases: A bibliometric study of the top 100 most cited publications

Background

In the field of autoimmune and inflammatory disorders, different approaches were applied to provide information regarding disease activity, comorbidities, epidemiological reports and risk factors. However, no previous studies had thoroughly analyzed the research trend in the field, and the bibliometric analysis focusing on pemphigoid diseases was available. The objective of the current study was to evaluate the current research trend in the field.

Methods

A search has been conducted for the Web of Science database based on various subcategories of pemphigoid diseases. Detailed information including articles' publication types, Author information, citation, and publication information was attained for further analysis.

Results

Within the 6,995 studies, the top 100 most-cited articles were extracted for analysis. Among the top 100 studies, 70% of the studies focused on bullous pemphigoid. More than 60% of the top 100 studies were studies with original data. Furthermore, 30% of the studies were guidelines and narrative reviews. For the issues primarily focused on, most of the high-impact studies described the molecular mechanism of pemphigoid diseases (26%), managements (19%), risk factors of pemphigoid diseases (17%). Additionally, some other studies provided general review or discussed about the issue of epidemiology, diagnosis/definition, comorbidities and clinical characteristics of pemphigoid diseases.

Conclusion

This comprehensive bibliographic study of pemphigoid diseases provided an overview of current research focuses in the field. Topics such as disease management, molecular mechanism of pathogenesis, and drug-inducing pemphigoid diseases were highly mentioned in the most-cited studies. For researchers and clinicians, the researching trend and study focus in the top-100 cited studies could serve as a potential reference for future investigation and patient management.

Bullous pemphigoid in a patient with a neuropsychological disorder and a possible novel drug trigger: A case report and review of the literature

A 59-year-old woman with schizoaffective disorder presented with an itchy, blistering generalised rash. One month prior, she had started empagliflozin, a sodium glucose transporter-2 (SGLT-2) inhibitor, used in type-2-diabetes. She was already established on paliperidone, an atypical antipsychotic, for 1 year. Serology at presentation was positive for anti-pemphigoid antibodies. Histology demonstrated subepidermal blistering, perivascular inflammation and eosinophils. Direct immunofluorescence was characteristic of bullous pemphigoid (BP), with linear IgG and C3 at the basement membrane. Both empagliflozin and paliperidone were discontinued. However, the blisters persisted. Treatment included: topical Dermovate and Eumovate ointment for the body and face respectively, alongside oral doxycycline 200 mg and prednisolone 40 mg for a week (reducing by 5 mg/week over 8 weeks). Nevertheless, new blisters continued developing, hence dapsone 50 mg was introduced, with significant improvement. Increasingly, several neurological and psychiatric disorders have been linked with BP, complicating aetiology and management. The underlying mechanism for these associations is not fully understood. Bullous pemphigoid autoantigens BP180 and BP230 are expressed in the central nervous system and it is thought that neurodegeneration may expose antigens to the immune system, generating a cross-reactive immune response. However, there also appears to be bidirectional causality between BP and neuropsychological conditions. Furthermore, as there was an association of empagliflozin initiation and BP onset, this further complicates the aetiology and presents a potential novel drug cause of BP. This case emphasises the neuropsychological issues associated with managing complex BP cases, a possible novel cause of drug-induced BP and highlights the likelihood of these issues becoming increasingly prevalent for the future.

Dipeptidyl Peptidase-4 Inhibitor-Related Bullous Pemphigoid: Clinical, Laboratory, and Histological Features, and Possible Pathogenesis

Dipeptidyl peptidase-4 inhibitor (DPP4i) is a widely used antidiabetic agent. Emerging cases of DPP4i-associated bullous pemphigoid (DBP), whose pathogenesis remains unclear, have been reported. Thus, a retrospective study was conducted from January 2016 to June 2021 to determine the clinical, laboratory, and histopathological features of DBP and idiopathic bullous pemphigoid (IBP). We set up in vitro experiments using vildagliptin-treated HaCaT keratinocytes to validate what we found by analyzing published RNA sequencing data about the genes related to the dermal-epidermal junction. We also observed IL-6 expression by HaCaT cells treated with vildagliptin. We enrolled 20 patients with DBP and 40 patients with IBP. The total Bullous Pemphigoid Disease Area Index (BPDAI) score was similar in both groups. However, the BPDAI score of erosions and blisters in DBP was significantly higher than that in IBP (24.6 vs. 16.68, p = 0.0189), and the score for urticaria and erythema was lower in DBP (12 vs. 19.05, p = 0.0183). The pathological features showed that the mean infiltrating eosinophil number per high-power field was significantly lower in DBP than in IBP (16.7 vs. 27.08, p = 0.023). The expression of LAMA3, LAMB3, LAMC2, DST, and COL17A1 decreased significantly in vildagliptin-treated human keratinocytes. On the other hand, IL-6, the hallmark cytokine of bullous pemphigoid (BP) severity, was found to be upregulated in HaCaT cells by vildagliptin. These experimental findings imply less of a requirement for eosinophil infiltration to drive the inflammatory cascades in DBP blistering. Both immunologic and non-immunologic pathways could be employed for the development of DBP. Our findings may help explain the higher incidence of non-inflammatory BP that was observed in DBP.

A Retrospective, Single-Institution Experience of Bullous Pemphigoid as an Adverse Effect of Immune Checkpoint Inhibitors

Immune checkpoint inhibitors are a class of cancer treatment drugs that stimulate the immune system's ability to fight tumor cells. These drugs are monoclonal antibodies targeting im-mune-inhibiting proteins on cancer cells, such as CTLA-4 and PD-1/PD-L1. Immune checkpoint inhibitors cause many immune-related adverse events. Cutaneous toxicities are of the most common adverse effects and occur with a range of severity. Bullous Pemphigoid is a rare adverse event with a high impact on quality of life that may occur after immune checkpoint inhibitor treatment. In this article, we investigate current research on immune checkpoint inhibitors, cutaneous adverse events, and common presentations and treatments, with a specific focus on Bullous Pemphigoid, its characteristics, onset timing, and treatment. Significant findings include a negative skew in the onset of presentation. Furthermore, we describe exclusive cases.

The significance of preclinical anti-BP180 autoantibodies

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease. Although the pathomechanism of BP onset has yet to be elucidated in detail, BP autoantibodies targeting two hemidesmosomal components, BP180 and BP230, are known to play a pivotal role in BP pathogenesis. Thus, the detection and measurement of BP autoantibodies are necessary for diagnosing BP and monitoring the disease activity. Immune assays such as immunofluorescence microscopy, immunoblotting, and ELISAs using BP180 and BP230 detect BP autoantibodies in most BP cases with high specificity; however, BP autoantibodies are sometimes detected in BP patients before the onset of this disease. BP autoantibodies that are detected in patients without typical tense blisters are defined as “preclinical BP autoantibodies”. These preclinical BP autoantibodies are detected even in a low percentage of normal healthy individuals. Although the importance of preclinical BP autoantibodies remains elusive, these autoantibodies might be a potential risk factor for subsequent BP development. Therefore, previous comparative epidemiological studies have focused on the prevalence of preclinical BP autoantibodies in populations susceptible to BP (e.g., the elderly) or in diseases with a higher risk of comorbid BP. This mini-review summarizes the literature on the prevalence of preclinical BP autoantibodies in patients with various conditions and diseases, and we discuss the significance of preclinical BP autoantibody detection.

Blisters and Milia around the Peritoneal Dialysis Catheter: A Case of Localized Bullous Pemphigoid

We report on the appearance of multiple tense blisters surrounding the exit site of a Tenckhoff catheter in a 79-year-old woman with end-stage renal disease in peritoneal dialysis. The differential diagnoses included a contact allergic or irritative dermatitis to peritoneal dialysis catheter material and antiseptic agents, bacterial infection, and herpes virus infection, but milia were a clue for a subepidermal blistering disease and lead to appropriate investigations. The laboratory findings, the histopathological examination and the direct immunofluorescence assay confirmed the diagnosis of localized bullous pemphigoid. The disorder typically occurs in elderly people and may be related to drugs, hematological malignancies or neurological conditions but it can also be a complication of hemodialysis or peritoneal dialysis.

Use of gliptins reduces levels of SDF-1/CXCL12 in bullous pemphigoid and type 2 diabetes, but does not increase autoantibodies against BP180 in diabetic patients

The use of dipeptidyl peptidase 4 (DPP4) inhibitors, (also known as gliptins), is associated with an increased risk of bullous pemphigoid (BP), an autoimmune blistering skin disease. To explore the mechanism behind gliptin-associated BP we investigated circulating autoantibodies against the major BP autoantigen BP180 in serum samples from patients with type 2 diabetes (T2D) with preceding gliptin medication (n = 136) or without (n = 136). Sitagliptin was the most frequently prescribed gliptin (125/136 patients). Using an ELISA assay, we showed that IgG autoantibodies against the immunodominant NC16A domain of BP180 were found in 5.9% of gliptin treated and in 6.6% of non-gliptin treated T2D patients. We found that 28% of gliptin treated patients had IgG autoantibodies recognizing the native full-length BP180 in ELISA, but among non-gliptin treated the seropositivity was even higher, at 32%. Further ELISA analysis of additional serum samples (n = 57) found no major changes in the seropositivity against BP180 during a follow-up period of about nine years. In immunoblotting, full-length BP180 was recognized by 71% of gliptin treated and 89% of non-gliptin treated T2D patients, but only by 46% of the age-and sex-matched controls. The chemokine stromal derived factor-1(SDF-1/CXCL12) is one of the major substrates of DPP4. Immunostainings showed that the expression of SDF-1 was markedly increased in the skin of BP patients, but not affected by prior gliptin treatment. We found that the use of gliptins decreased the serum level of SDF-1α in both BP and T2D patients. Our results indicate that the autoantibodies against the linear full-length BP180 are common in patients with T2D, but seropositivity is unaffected by the use of sitagliptin.

Mechanisms of dermatologic toxicities to immune checkpoint inhibitor cancer therapies

The discovery of immune checkpoint inhibition (ICI) sparked a revolution in the era of targeted anticancer therapy. While monoclonal antibodies targeting the CTLA-4 and PD-1 axes have improved survival in patients with advanced cancers, these immunotherapies are associated with a wide spectrum of dermatologic immune-related adverse events (irAEs). Several publications have addressed the clinical and histopathologic classification of these skin-directed irAEs, their impact on antitumor immunity and survival, and the critical role of supportive oncologic dermatology in their management. Here, we review the current understanding of the mechanistic drivers of immune-related skin toxicities with a focus on inflammatory, immunobullous, melanocyte/pigment-related reactions. We detail the specific immune-based mechanisms that may underlie different cutaneous reactions. We also discuss potential mechanisms as they relate to non-cutaneous irAEs and potential overlap with cutaneous irAEs, techniques to study differences in immune-related versus de novo skin reactions, and how treatment of these adverse events impacts cancer treatment, patient quality of life, and overall survival. An improved understanding of the mechanistic basis of cutaneous irAEs will allow us to develop and utilize blood-based biomarkers that could help ultimately predict onset and/or severity of these irAEs and to implement rational mechanistic-based treatment strategies that are targeted to the irAEs while potentially avoiding abrogating anti-tumor effect of ICIs.

Associations of thiazide use with skin cancers: a systematic review and meta-analysis

BACKGROUND

Previous findings on the associations of thiazide use with skin cancers were conflicting. This study aimed to examine the associations of individual thiazide use with skin cancer risk, differentiated by subtypes of skin cancers, geographic regions, and cumulative doses of individual thiazides.

METHODS

We searched PubMed, Embase, and Cochrane Central Register of Controlled Trials for relevant studies on January 5, 2022, scanned the references of included studies, and consulted experts. We included case-control and cohort studies or randomized trials reporting the associations of individual thiazide or thiazide-like diuretics use with skin cancers. Non-melanoma skin cancer (NMSC) and melanoma were analysed separately. A random-effects model meta-analysis was conducted for pooled odds ratio (OR) and hazard ratio (HR) for skin cancers related to individual thiazide use.

RESULTS

We included 15, 5, and 5 case-control or cohort studies reporting the risk for skin cancers associated with hydrochlorothiazide, bendroflumethiazide, and indapamide use, respectively, with 17,848,313 participants. The meta-analysis showed associations of hydrochlorothiazide use with increased risk of NMSC (OR 1.16, 95% CI 1.08-1.24; HR 1.26, 95% CI 1.04-1.54), squamous cell carcinoma (SCC) (OR 1.32, 95% CI 1.06-1.65; HR 1.61, 95% CI 0.97-2.67), and melanoma (OR 1.11, 95% CI 1.02-1.20; HR 1.03, 95% CI 0.93-1.14). The increased risks for SCC were associated with high cumulative doses of hydrochlorothiazide (OR 2.56, 95% CI 1.43-4.57; HR 1.20, 95% CI 1.00-1.45). Hydrochlorothiazide use was associated with different subtypes of melanoma including superficial spreading (OR 1.18, 95% CI 1.05-1.33), nodular (OR 1.23, 95% CI 1.08-1.39), and lentigo maligna melanoma (OR 1.33, 95% CI 1.08-1.65). Various cumulative doses of hydrochlorothiazide were associated with increased odds for melanoma. However, the associations of hydrochlorothiazide use with increased risk of NMSC and melanoma only appeared in non-Asian countries. No meaningful increase in the risk for skin cancers was associated with bendroflumethiazide and indapamide.

CONCLUSIONS

Hydrochlorothiazide is associated with an increased risk for NMSC (especially SCC) and melanoma in non-Asian countries, whereas bendroflumethiazide and indapamide are not associated with a meaningful risk for skin cancers. Healthcare professionals and patients should be informed of the different risk profiles of skin cancers associated with different thiazides, cumulative doses, and regions.

TRIAL REGISTRATION

PROSPERO CRD42021234317 .

Serum autoantibody reactivity in bullous pemphigoid is associated with neuropsychiatric disorders and the use of antidiabetics and antipsychotics: a large prospective cohort study

BACKGROUND

Bullous pemphigoid (BP), the by far most frequent autoimmune blistering skin disease (AIBD), is immunopathologically characterized by autoantibodies against the two hemidesmosomal proteins BP180 (collagen type XVII) and BP230 (BPAG1 or dystonin). Several comorbidities and potentially disease-inducing medication have been described in BP, yet, a systematic analysis of these clinically relevant findings and autoantibody reactivities has not been performed.

OBJECTIVE

To determine associations of autoantibody reactivities with comorbidities and concomitant medication.

METHODS

In this prospective multicenter study, 499 patients diagnosed with BP in sixteen European referral centers were included. The relation between anti-BP180 NC16A and anti-BP230 IgG ELISA values at the time of diagnosis as well as comorbidities and concomitant medication collected by a standardized form were analyzed.

RESULTS

An association between higher serum anti-BP180 reactivity and neuropsychiatric but not atopic and metabolic disorders was observed as well as with the use of insulin or antipsychotics but not with dipeptidyl peptidase-4 (DPP4) inhibitors, inhibitors of platelet aggregation and L-thyroxine. The use of DPP4 inhibitors was associated with less anti-BP180 and anti-BP230 reactivity compared to BP patients without these drugs. This finding was even more pronounced when compared with diabetic BP patients without DPP4 inhibitors. Associations between anti-BP180 and anti-BP230 reactivities were also found in patients using insulin and antipsychotics, respectively, compared with patients without this medication, but not for the use of inhibitors of platelet aggregation, and L-thyroxine.

CONCLUSION

Taken together, these data imply a relation between autoantibody reactivities at the time of diagnosis and both neuropsychiatric comorbidities as well as distinct concomitant medication suggesting a link between the pathological immune mechanisms and clinical conditions that precede the clinically overt AIBD.

Successful Treatment of Bullous Pemphigoid Lesions by Berberine Stamp Therapy: A Case Report and Literature Review

Bullous pemphigoid (BP) is a life-threatening autoimmune disease of the skin that is mainly characterized by a large range of tension blisters and intense itching of the skin. The 1-year mortality rate of BP was 23.5%. Superinfection caused by skin lesion ulceration is one of the important causes of disease death. Therefore, it is challenging to control infection and improve skin wound healing. Here, we report the case of an elderly woman who presented with BP and involved the oral mucosa. The patient was successfully treated with hormones combined with topical berberine, and 95% of the patients’ lesions healed completely after 1 month. In addition, we inductively analyzed the current treatments for BP to provide a reference for BP clinical treatment.

Dipeptidyl peptidase-4 inhibitors and gallbladder or biliary disease in type 2 diabetes: systematic review and pairwise and network meta-analysis of randomised controlled trials

OBJECTIVE

To examine the association between dipeptidyl peptidase-4 inhibitors and gallbladder or biliary diseases.

DESIGN

Systematic review and pairwise and network meta-analysis.

DATA SOURCES

PubMed, EMBASE, Web of Science, and CENTRAL from inception until 31 July 2021.

ELIGIBILITY CRITERIA

Randomised controlled trials of adult patients with type 2 diabetes who received dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists, and sodium-glucose cotransporter-2 inhibitors compared with placebo or other antidiabetes drugs.

MAIN OUTCOME MEASURES

Composite of gallbladder or biliary diseases, cholecystitis, cholelithiasis, and biliary diseases.

DATA EXTRACTION AND DATA SYNTHESIS

Two reviewers independently extracted the data and assessed the quality of the studies. The quality of the evidence for each outcome was assessed using the Grading of Recommendations, Assessment, Development and Evaluations framework (GRADE) approach. The meta-analysis used pooled odds ratios and 95% confidence intervals.

RESULTS

A total of 82 randomised controlled trials with 104 833 participants were included in the pairwise meta-analysis. Compared with placebo or non-incretin drugs, dipeptidyl peptidase-4 inhibitors were significantly associated with an increased risk of the composite of gallbladder or biliary diseases (odds ratio 1.22 (95%confidence interval 1.04 to 1.43); risk difference 11 (2 to 21) more events per 10 000 person years) and cholecystitis (odds ratio 1.43 (1.14 to 1.79); risk difference 15 (5 to 27) more events per 10 000 person years) but not with the risk of cholelithiasis and biliary diseases. The associations tended to be observed in patients with a longer duration of dipeptidyl peptidase-4 inhibitor treatment. In the network meta-analysis of 184 trials, dipeptidyl peptidase-4 inhibitors increased the risk of the composite of gallbladder or biliary diseases and cholecystitis compared with sodium-glucose cotransporter-2 inhibitors but not compared with glucagon-like peptide-1 receptor agonists.

CONCLUSIONS

Dipeptidyl peptidase-4 inhibitors increased the risk of cholecystitis in randomised controlled trials, especially with a longer treatment duration, which requires more attention from physicians in clinical practice.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021271647.

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.

Association between sodium-glucose co-transporter 2 inhibitors and risk of bullous pemphigoid in patients with type 2 diabetes: A nationwide population-based cohort study

BACKGROUND

Certain anti-diabetic agents have been linked to the development of bullous pemphigoid (BP). However, the relationship between BP and sodium-glucose co-transporter 2 inhibitors (SGLT2is) remains inconclusive.

OBJECTIVE

To investigate the association between SGLT2i usage and BP.

METHODS

Participants were recruited from the Taiwan National Health Insurance Database between 2007 and 2018. A total of 149,060 patients with diabetes receiving SGLT2i were matched 1:2 with diabetic patients without SGLT2i usage. Factors such as age, sex, duration of diabetes condition, DPP4i usage, insulin usage, and selected comorbidities were included in the multivariate analysis.

RESULTS

Compared with the control, the 2-year-cumulative incidence was significantly low in patients using SGLT2i after adjustment for competing mortality. Patients with diabetes receiving SGLT2i had a low risk (adjusted hazard ratio [HR] 0·56, 95% confidence interval [CI], 0·33-0·96) for BP after adjustment for potential confounders. Age (HR, 1·06), renal disease (HR, 1·79), cerebrovascular disease (HR, 3·23), epilepsy (HR, 3·07), DPP4i users (HR: 2·55), and insulin users (HR: 2·56) were significant risk factors for BP.

CONCLUSIONS

The risk of BP did not increase in patients receiving SGLT2i. Thus, SGLT2i could be a safe choice for patients with diabetes having additional risk factors or a history of BP.

Efficacy and mechanisms of traditional Chinese medicine for COVID-19: a systematic review

Since the outbreak of coronavirus disease 2019 (COVID-19), traditional Chinese medicine (TCM) has made an important contribution to the prevention and control of the epidemic. This review aimed to evaluate the efficacy and explore the mechanisms of TCM for COVID-19. We systematically searched 7 databases from their inception up to July 21, 2021, to distinguish randomized controlled trials (RCTs), cohort studies (CSs), and case–control studies (CCSs) of TCM for COVID-19. Two reviewers independently completed the screening of literature, extraction of data, and quality assessment of included studies. Meta-analysis was performed using Review Manager 5.4 software. Eventually, 29 RCTs involving 3060 patients and 28 retrospective studies (RSs) involving 12,460 patients were included. The meta-analysis demonstrated that TCM could decrease the proportion of patients progressing to severe cases by 55% and the mortality rate of severe or critical patients by 49%. Moreover, TCM could relieve clinical symptoms, curtail the length of hospital stay, improve laboratory indicators, and so on. In addition, we consulted the literature and obtained 149 components of Chinese medicinal herbs that could stably bind to antiviral targets or anti-inflammatory or immune-regulating targets by the prediction of molecular docking. It suggested that the mechanisms involved anti-virus, anti-inflammation, and regulation of immunity. Our study made a systematic review on the efficacy of TCM for COVID-19 and discussed the possible mechanisms, which provided clinical reference and theoretical basis for further research on the mechanism of TCM for COVID-19.

Risk of All-Cause Mortality, Cardiovascular Disease Mortality, and Cancer Mortality in Patients With Bullous Pemphigoid

IMPORTANCE

The role of bullous pemphigoid (BP) in cardiovascular disease (CVD) mortality remains controversial, and analyses of causes of death among patients with BP based on individual data remain lacking.

OBJECTIVE

To evaluate the risk of all-cause mortality, CVD mortality, and cancer mortality in patients with BP.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study identified patients who received a diagnosis of and treatment for BP during their dermatology clinic visits at a tertiary medical center in central Taiwan between January 1, 2007, and December 31, 2017. Controls were patients without BP and were individually matched to cases (4:1) according to age, sex, and date of the dermatology clinic visit. Data were analyzed from March 6, 2019, to April 2, 2021.

EXPOSURES

Bullous pemphigoid was confirmed pathologically with typical direct immunofluorescence findings or clinically with typical clinical presentation, positive findings of an anti-basement membrane zone antibody test, and corticosteroid use for at least 28 cumulative days.

MAIN OUTCOMES AND MEASURES

Mortality outcomes confirmed by the National Death Registry.

RESULTS

Of 252 patients with BP and 1008 matched control patients (N = 1260), 685 (54.4%) were men and the median age was 78.0 (IQR, 70.3-84.8) years. Patients with BP had higher CVD mortality at 1 year (20 [7.9%] vs 13 [1.3%]), 3 years (28 [11.1%] vs 24 [2.4%]), and 5 years (31 [12.3%] vs 39 [3.9%]) compared with matched control patients. After adjusting for potential confounding variables, patients with BP had a 5-fold higher risk of CVD mortality at 1 year (hazard ratio [HR], 5.29 [95% CI, 2.40-11.68]), 3 years (HR, 5.79 [95% CI, 3.11-10.78]), and 5 years (HR, 4.95 [95% CI, 2.88-8.51]). Subgroup analyses revealed that the CVD mortality risk associated with BP was higher in patients without a history of hypertension (HR, 7.28 [95% CI, 3.87-13.69]) or CVD (HR, 6.59 [95% CI, 3.40-12.79]) and in patients without prior diuretic use (HR, 5.75 [95% CI, 3.15-10.50]) compared with matched control patients. In addition, all-cause mortality associated with BP was higher in patients without prior corticosteroid use than in control patients (HR 5.65 [95% CI, 4.19-7.61]).

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that BP was associated with a 5-fold higher risk of CVD mortality, particularly in patients without underlying hypertension or CVD or those without prior corticosteroid or diuretic use. Future studies should investigate the benefits of routine monitoring and timely management of CVD symptoms and signs in patients with BP.

DPP-4 Inhibitors and Increased Reporting Odds of Bullous Pemphigoid: A Pharmacovigilance Study of the FDA Adverse Event Reporting System (FAERS) from 2006 to 2020

BACKGROUND

In recent years, an association between dipeptidyl peptidase-4 (DPP-4) inhibitors and bullous pemphigoid has been detected in pharmacovigilance studies in European and Asian countries; however, no pharmacovigilance data have been published yet in the USA.

OBJECTIVE

The objective of this study was to examine the relationship between bullous pemphigoid and DPP-4 inhibitors and other oral diabetes mellitus medications in the FDA Adverse Event Reporting System (FAERS).

METHODS

Case/non-case analyses were performed in the FAERS using data from 2006 to 2020 to examine the reporting odds ratio (ROR) signal for bullous pemphigoid for all classes of oral diabetes medications. These analyses were performed under multiple conditions to control for bias: (1) comparison to all other drugs in the FAERS; (2) comparison to other diabetes medications; and (3) comparison to all other diabetes medications where only a single agent was implicated.

RESULTS

A statistically significant ROR for bullous pemphigoid was found for DPP-4 inhibitors under all conditions: (1) 109.79 (95% confidence interval [CI] 101.61-118.62); (2) 74.46 (95% CI 60.58-91.52); and (3) 35.94 (95% CI 27.91-46.28). A larger signal was seen for non-US Food and Drug Administration (FDA)-approved (anagliptin, vildagliptin, teneligliptin) vs FDA-approved DPP-4 inhibitors (alogliptin, linagliptin, saxagliptin, sitagliptin), likely because of an overestimation of the ROR for non-FDA-approved drugs. The largest signal was seen under conditions 1 and 2 with vildagliptin (1) 1022.83 (95% CI 909.45-1150.35) and (2) 158.84 (95% CI 127.01-198.66) followed by anagliptin (1) 628.63 (95% CI 221.36-1785.24) and (2) 60.64 (95% CI 20.98-175.26), alogliptin, teneligliptin, linagliptin, sitagliptin, and saxagliptin. Under condition 3, the largest signal was seen with linagliptin 122.25 (95% CI 93.96-159.07). Both metformin and the sulfonylureas had a significant ROR under condition 2 [3.42 (95% CI 3.01-3.89) and 2.07 (95% CI 1.66-2.57) respectively]; however, this association was not present under condition 3 as only confounded cases occurred, and a large majority of reported cases had concurrent exposure to a DPP-4 inhibitor.

CONCLUSIONS

Our findings support an association between DPP-4 inhibitors and bullous pemphigoid. This association was maintained under controls to limit bias and falsely elevated signal, including controlling for disease state and cases with multiple drug exposures. Non-FDA-approved DPP-4 inhibitors had a larger ROR compared with FDA-approved DPP-4 inhibitors, likely owing to fewer reported adverse effects overall for non-FDA-approved drugs in FAERS.

Bullous Pemphigoid: A Multifactorial Review of a Dermatologic Mystery

Bullous pemphigoid is the most common autoimmune bullous skin disease and primarily affects patients older than 60 years. This chronic disease can lead to significant morbidity characterized by spontaneous remissions and exacerbations. Although the etiopathogenesis is uncertain, it is proposed that certain drugs (especially polypharmacy), vaccinations, infections, and exposures precede the dermatological presentation. Bullous pemphigoid patients initially present with moderate-to-severe pruritis with or without eczematous or urticarial lesions, followed by the development of cutaneous bullae weeks to months later testing with a notable false-positive Nikolsky sign. As frontline providers, emergency department nurse practitioners should be aware of these skin diseases in the elderly. Prompt recognition of bullous pemphigoid leads to an earlier diagnosis and management of this common autoimmune bullous skin disease and requires clinicians to have critical observation skills.

Bipolar Patients and Bullous Pemphigoid after Risperidone Long-Acting Injectable: A Case Report and a Review of the Literature

Neuropsychiatric disorders are found to be associated with bullous pemphigoid (BP), an autoimmune subepidermal blistering disease. Antipsychotics have emerged as possible inducing factors of BP. However, large sample studies concerning BP associated with antipsychotics, as well as with specific mental disorders, are still lacking. Our review retrieved a few clinical studies and case reports on the topic, producing controversial results. We report for the first time a bipolar patient case presenting BP following five-month therapy with risperidone long-acting injectable (LAI). We hypothesize that the dermatological event is associated with the medication administered. The issue emerged during psychiatric consultation and was confirmed by histological examination, direct and indirect immunofluorescence studies, plus positive plasma and cutaneous BP180 and BP230 IgG. Neurodegeneration or neuroinflammation might represent a primary process leading to a cross-reactive immune response between neural and cutaneous antigens and contributing to self-tolerance failure. Furthermore, the time sequence of the shared biological mechanisms leading to clinical manifestations of the neuropsychiatric disorder and BP remains undefined. BP comorbid with bipolar disorder might occasionally represent a serious health risk and affect patients' physical and psychosocial quality of life. Thus, clinicians treating psychiatric patients should consider BP as a possible adverse effect of psychotropic medications.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Bullous Autoimmune Dermatoses–Clinical Features, Diagnostic Evaluation, and Treatment Options

BACKGROUND

Bullous autoimmune dermatoses are a clinically and immunopatho - logically heterogeneous group of diseases, characterized clinically by blisters or erosions of the skin and/or mucous membranes. In Germany, their prevalence is approximately 40 000 cases nationwide, and their incidence approximately 20 new cases per million people per year.

METHODS

This review is based on publications that were retrieved by a selective search of the literature focusing on the current German and European guidelines.

RESULTS

Recent years have seen the publication of guidelines, controlled prospective clinical trials, and multicenter diagnostic studies improving both diagnosis and therapy. Specific monovalent and multivariate serological test systems and pattern analysis of tissue-bound autoantibodies allow identification of the target antigens in 80-90% of patients. This enables the precise classification of disease entities, with implications for treatment selection and disease outcome. In 2019, the anti-CD20 antibody rituximab was approved by the European Medicines Agency for the treatment of moderate and severe pemphigus vulgaris, with an ensuing marked improvement in the care of the affected patients. To treat mild and moderate bullous pemphigoid, topical clobetasol proprionate is recommended, in severe disease, combined with systemic treatment, i.e. usually (a) prednisolone p.o. at an initial dose of 0.5mg/kg/d , (b) an immunomodulant, e.g. dapsone or doxycycline, or (c) prednisolone plus an immunomodulant.

CONCLUSION

The early recognition and precise diagnostic evaluation of bullous autoimmune dermatoses now enables improved, often interdisciplinary treatment, in accordance with the available guidelines. Current research projects are focused on new treatment approaches, an improved understanding of the underlying pathophysiology, and further refinements of diagnostic techniques.

Defining dipeptidyl peptidase-4 inhibitors-related bullous pemphigoid: A single-centre retrospective study

BACKGROUND

Many studies have corroborated the association of dipeptidyl peptidase-4 inhibitors (DPP4i) use with bullous pemphigoid (BP). It has been speculated that this drug-induced variant presents with a different clinical spectrum than conventional BP.

OBJECTIVE

To determine the prevalence of DPP4i-induced cases of BP and to evaluate whether gliptin-related BP has specific clinicopathological and immunological features.

METHODS

We conducted a retrospective, observational study of BP cases attended at our centre between January 2000 and June 2020. Epidemiological, clinical, histopathological and laboratory data were collected.

RESULTS

A total of 257 cases of BP were collected; 51 (24.3%) were on treatment with DPP4i. When analysing DPP4i-induced BP cases, generalized BP was the predominant pattern and scalp/mucosal involvement was found in 13 patients. Gliptin-related BP cases were associated to a decrease in the eosinophilic infiltrate (p = 0.000) and both the detection rate and concentration of anti-BP180 IgG were lower (p = 0.004, p = 0.001, respectively) than non-DPP4i cases.

LIMITATIONS

Retrospective, single-centre study.

CONCLUSION

Our large DPP4i-induced BP case series has highlighted that DPP4i-induced BP is characterized by generalized lesions and scalp involvement. Lower titres of anti-BP180 antibodies and a decrease in eosinophils infiltrating into the skin may be distinct features of DPP4i-related BP.

The association of bullous pemphigoid with dipeptidyl-peptidase 4 inhibitors: a ten-year prospective observational study

BACKGROUND

Bullous pemphigoid is the most common bullous chronic autoimmune skin disease. Recent studies have suggested dipeptidyl-peptidase 4 inhibitors as possible predisposing agents of bullous pemphigoid. The objective of our study was to prospectively estimate the association between gliptins and the development of bullous pemphigoid.

METHODS

We conducted a prospective study which included all patients diagnosed with biopsy-proven bullous pemphigoid in the Dermatology Department of our hospital between April 1, 2009 and December 31,2019. The diagnosis of bullous pemphigoid was based on specific clinical, histological and immunological features.

RESULTS

Overall 113 consecutive patients (age 75 ± 13 years, 62 females) with the diagnosis of bullous pemphigoid were enrolled. Seventy-six patients (67.3%) suffered from type 2 Diabetes and 52 (46%) were treated with dipeptidyl-peptidase 4 inhibitors. The most frequent prescribed gliptin was vildagliptin, being administered to 45 cases (39.8% of total patients enrolled, 86.5% of the patients treated with gliptins). Gliptins were withdrawn immediately after the diagnosis of bullous pemphigoid, which together with steroid administration led to remission of the rash.

CONCLUSIONS

This study revealed that treatment with dipeptidyl-peptidase 4 inhibitors, especially vildagliptin, is significantly associated with an increased risk of bullous pemphigoid development.