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

Artificial Intelligence Useful in the Practice of Geriatric Dermatology?

Geriatric dermatology has risen in importance through the years, alongside a steadily ageing global population. Simultaneously, artificial intelligence (AI) technologies have become more advanced, and AI has been found to be useful in the general practice of dermatology. Whether or not, and how AI can be useful in the practice of geriatric dermatology remains unanswered. We explore the intricacies and potential roles AI can play in the practice of geriatric dermatology and recommend that physicians should recognize the tremendous potential of AI, in terms of facilitating diagnoses of disease, guiding and personalizing therapeutics and even expanding therapeutic options, whilst remaining cautious about AI's current pitfalls and acceptability amongst its elderly audience.

Bullous pemphigoid and diabetes mellitus: a systematic review and meta-analysis

We aimed to systematically review and meta-analyze the association between diabetes mellitus (DM) and bullous pemphigoid (BP). Bullous pemphigoid (BP) is a prevalent autoimmune subepidermal blistering disease. Comorbid health conditions like neurological diseases and malignancies have been associated with BP. Growing evidence suggests that type 2 diabetes mellitus (T2DM) may increase the risk of developing BP. This review aims to synthesize this evidence. A systematic literature review was performed using Medline, PubMed, and Scopus in March 2022. Studies exploring the association between BP and DM were included. Data were extracted, and quality was assessed using the Newcastle-Ottawa scale. Meta-analysis was conducted to identify the odds ratio (OR) and 95% confidence intervals (CI) of the association. Seventeen studies were included, most being case-control studies from Europe and Asia. The pooled OR was 2.06 (95% CI: 1.61-2.62), suggesting a significant association between DM and BP. However, strong heterogeneity (I2 = 88%) was observed. Evidence consolidates a significant relationship between DM and BP, potentially due to alterations in the immune system and skin properties caused by diabetes. Strengths of this review include a comprehensive search, rigorous methodology, large sample size, and heterogeneity evaluation. However, varying study quality, potential publication bias, and unaccounted confounding factors present limitations. There is a potential link between T2DM and an increased risk of BP. Further studies are required to understand this association and the underlying mechanisms.

Prevalence of a large panel of systemic autoantibodies in the Bavarian adult population

Objective

Autoimmune diseases commonly feature the presence of specific humoral autoantibodies. However, the prevalence of a large panel of systemic autoantibodies has never been assessed in the general population. We, therefore, described the prevalence of about 50 humoral systemic autoantibodies in a sample of the general Bavarian adult population.

Methods

Non-fasting venous serum samples from 331 participants were analyzed for 7 autoantibody screening tests (nuclear, cytoplasmic, and mitotic ANA, ANCA, cANCA and pANCA, anti-ENA autoantibodies) and 44 different monospecific humoral non-organ specific/systemic autoantibodies using indirect immunofluorescence tests, ELISAs, and line blots. In order to assess associations between sex, age, BMI, education level, smoking status and the presence of systemic autoantibodies, logistic regression analyses were conducted.

Results

At least one screening test was positive in 29.9% of the participants, and 42.3% of the participants were seropositive for at least one monospecific autoantibody. The most frequently found monospecific autoantibodies were rheumatoid factor (35.6%), ß2-glycoprotein 1 IgM (4.8%), and cardiolipin IgG (1.8%). Only few associations between sex, age, BMI, education, smoking status and autoantibody frequencies were observed.

Conclusion

Systemic autoantibodies are common in the general Bavarian population, and largely independent of sex, age, BMI, education, or smoking status. The study results may give orientation to clinicians about the occurrence of autoantibodies in the population, not (yet) associated with clinical symptoms.

Diagnosis and Management of Bullous Disease

Bullous diseases are a group of dermatoses primarily characterized by the presence of vesicles (0.1-0.9 cm) or bullae (>1 cm). There are various categories of bullous disease: allergic, autoimmune, infectious, mechanical, and metabolic. These diseases affect individuals in all decades of life, but older adults, age 65 and older, are particularly susceptible to bullous diseases of all etiologies. The incidence of these disorders is expected to increase given the advancing age of the general population. In this comprehensive review, we will outline the common bullous diseases affecting older individuals and provide an approach to evaluation and management.

The relationship between bullous pemphigoid and renal disease and related treatments: a review of the current literature

INTRODUCTION

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disorder in older adults. There is increasing evidence that BP has connections with renal diseases, such as glomerulopathy and neoplasm; it is also linked to the receipt of renal replacement therapy.

AREAS COVERED

In this review, we summarize the current evidence that BP is a comorbidity of common renal diseases. Furthermore, our exploration of the characteristics and possible mechanisms underlying these connections provides insights that may facilitate the prevention, diagnosis, and management of BP.

EXPERT OPINION

There is mounting proof that BP is not just a skin immunological disorder but rather a systemic immune-mediated illness. Quantities of case reports focused on BP as a renal disease comorbidity and the coexistence of them is not accidental. However, the underlying mechanisms are still needed to be investigated. Clinicians should be alert to the comorbidities in order to facilitate effective treatment and improve patient prognosis.

Cellular senescence in skin-related research: Targeted signaling pathways and naturally occurring therapeutic agents

Despite the growing interest by researchers into cellular senescence, a hallmark of cellular aging, its role in human skin remains equivocal. The skin is the largest and most accessible human organ, reacting to the external and internal environment. Hence, it is an organ of choice to investigate cellular senescence and to target root-cause aging processes using senolytic and senomorphic agents, including naturally occurring plant-based derivatives. This review presents different aspects of skin cellular senescence, from physiology to pathology and signaling pathways. Cellular senescence can have both beneficial and detrimental effects on the skin, indicating that both prosenescent and antisenescent therapies may be desirable, based on the context. Knowledge of molecular mechanisms involved in skin cellular senescence may provide meaningful insights for developing effective therapeutics for senescence-related skin disorders, such as wound healing and cosmetic skin aging changes.

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

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

Spontaneous autoimmune subepidermal blistering diseases in animals: a comprehensive review

Autoimmune subepidermal blistering diseases (AISBDs) are rare skin disorders of animals that were first identified in dogs but several AISBDs are now recognised in other companion animal species. Most AISBDs in animals are homologues of the human diseases and are thought to share similar pathomechanisms of epidermal and/or mucosal blister formation caused by autoantibodies targeting structural proteins of the basement membrane zone (BMZ). Disruption of their structural function by the autoantibodies and/or recruited inflammation leads to BMZ fragility, which presents clinically as vesicles, bullae and, later, deep erosions and ulcers. Canine AISBDs are the best characterised, particularly the more common variants such as mucous membrane pemphigoid (48%), epidermolysis bullosa acquisita (EBA) (26%), and bullous pemphigoid (10%). Exceedingly rare AISBDs in the dog are junctional EBA, mixed AISBD, type-1 bullous systemic lupus erythematosus, linear IgA dermatosis, and pemphigus gestationis. The diagnosis of a specific AISBD is made by combining the clinical features (breed, age, lesion distribution) with histological evidence of subepithelial clefting, but not all AISBDs can be differentiated in this manner and specialised immunological testing is required. This latter, unfortunately, is not readily available and, therefore, the specific AISBD diagnosis often remains unconfirmed. While this limits further understanding of these diseases, it does not prevent clinicians from treating their patients, as the treatment approaches are similar for the different AISBDs in dogs. This review primarily focuses on canine AISBDs, the species for which these diseases have been best characterised, and shorter descriptions of variants in other species are also provided.

Lisinopril prevents bullous pemphigoid induced by dipeptidyl peptidase 4 inhibitors via the Mas receptor pathway

Recent studies have suggested that dipeptidyl peptidase 4 (DPP4) inhibitors increase the risk of development of bullous pemphigoid (BP), which is the most common autoimmune blistering skin disease; however, the associated mechanisms remain unclear, and thus far, no therapeutic targets responsible for drug-induced BP have been identified. Therefore, we used clinical data mining to identify candidate drugs that can suppress DPP4 inhibitor-associated BP, and we experimentally examined the underlying molecular mechanisms using human peripheral blood mononuclear cells (hPBMCs). A search of the US Food and Drug Administration Adverse Event Reporting System and the IBM^® MarketScan^® Research databases indicated that DPP4 inhibitors increased the risk of BP, and that the concomitant use of lisinopril, an angiotensin-converting enzyme inhibitor, significantly decreased the incidence of BP in patients receiving DPP4 inhibitors. Additionally, in vitro experiments with hPBMCs showed that DPP4 inhibitors upregulated mRNA expression of MMP9 and ACE2, which are responsible for the pathophysiology of BP in monocytes/macrophages. Furthermore, lisinopril and Mas receptor (MasR) inhibitors suppressed DPP4 inhibitor-induced upregulation of MMP9. These findings suggest that the modulation of the renin-angiotensin system, especially the angiotensin1-7/MasR axis, is a therapeutic target in DPP4 inhibitor-associated BP.

Analysis of the clinical characteristics of pembrolizumab-induced bullous pemphigoid

Background

Pembrolizumab, a programmed cell death protein 1 checkpoint inhibitor, is a novel drug used to treat a variety of advanced malignancies. However, it can also result in many immune-related adverse events, with cutaneous toxicities being the most frequent. Regarding pembrolizumab-induced skin adverse reactions, bullous pemphigoid (BP) has the worst effects on quality of life. Recently, there have been more and more reports of BP incidents resulting from pembrolizumab therapy in patients with cancer. This study aimed to define the clinical characteristics, diagnosis and management of pembrolizumab-induced BP and identify potential differences between classical BP and pembrolizumab-induced BP.

Methods

Case reports, case series, and case analyses of pembrolizumab-induced BP up to 10 December 2022 were collected for retrospective analysis.

Results

Our study included 47 patients (33 males and 14 females) from 40 studies. The median age was 72 years (range 42-86 years). The median time to cutaneous toxicity was 4 months (range 0.7-28 months), and the median time to bullae formation was 7.35 months (range 0.7-32 months). The most common clinical features were tense bullae and blisters (85.11%), pruritus (72.34%), and erythema (63.83%) on the limbs and trunk. In 20 of the 22 cases tested, the serum anti-BP180 autoantibodies were positive. However, in 10 cases (91.90%, 10/11) the circulating autoantibodies of anti-BP230 were negative. 40 patients had skin biopsies and the skin biopsy revealed subepidermal bullae or blister eosinophil infiltration in 75.00% of patients with pembrolizumab-induced BP, 10.00% of patients with lymphocyte infiltration and 20.00% of patients with neutrophil infiltration. There were 20 patients (50%) with eosinophilic infiltration around the superficial dermis vessels, 8 patients (20.00%) with lymphocyte infiltration around the superficial dermis vessels, and 4 patients (10.00%) with neutrophil infiltration around the superficial dermis vessels. Direct immunofluorescence detected linear immunoglobulin G (IgG) IgG and/or complement C3 along the dermo-epidermal junction in 36 patients (94.74%) with BP. IgG positivity was detected by indirect immunofluorescence in 81.82% of patients with BP. All patients were in complete remission (95.65%,44/46) or partial remission (4.35%, 2/46) of BP, whereas 9/46 patients had a relapse or refractory. The majority of patients achieved BP remission after discontinuation of pembrolizumab with a combination of topically and systemically administered steroid treatments, or other medications. The median duration of BP remission was 2 months (range 0.3-15 months).

Conclusion

A thorough diagnosis of pembrolizumab-induced BP should be made using clinical signs, biochemical markers, histopathological and immunopathological tests. Pembrolizumab-induced BP had similar clinical characteristics to classic BP. Temporary or permanent discontinuation of pembrolizumab therapy may be required in patients with perbolizumab-induced BP depending on the severity of BP and the response to medication. Pembrolizumab-induced BP may be effectively treated using topical and systemic steroid treatments in combination with other medications (e.g., doxycycline, niacinamide, dapsone, rituximab, intravenous immunoglobulins, dupilumab, cyclophosphamide, methotrexate, mycophenolate mofetil, and infliximab). Clinicians should provide better management to patients with BP receiving pembrolizumab to prevent progression and ensure continuous cancer treatment.

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.

[Trigger factors associated with bullous autoimmune dermatoses]

BACKGROUND

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

[Bullous autoimmune dermatoses of the mucous membranes]

Autoimmune bullous diseases (AIBD) comprise a group of organ-specific autoimmune diseases which are characterised by the production of autoantibodies against adhesion molecules and structural proteins of skin and mucosae. Depending on the target protein, AIBD are classified into intraepidermal (pemphigus group) and subepidermal (pemphigoid group, epidermolysis bullosa acquisita, dermatitis herpetiformis) blistering disorders. Depending on the clinical entity, patients can develop blisters, pustules, erosions, and erythema on the skin and mucosae.

Blasenbildende Autoimmundermatosen – Klinik, Diagnostik und neue Therapieansätze

Diese Arbeit gibt eine Übersicht über die Gruppe blasenbildender Autoimmundermatosen und stellt deren wichtigste Vertreter, das bullöse Pemphigoid, den Pemphigus vulgaris sowie den Pemphigus foliaceus, vor. Die häufigste der insgesamt seltenen blasenbildenden Autoimmundermatosen ist das bullöse Pemphigoid (BP). Es betrifft vor allem Patienten jenseits des 60. Lebensjahrs. Charakterisiert ist es typischerweise durch das Auftreten praller Blasen, die mit einem heftigen Juckreiz einhergehen. Ein längeres, sogenanntes prämonitorisches Stadium ohne Blasenbildung ist nicht ungewöhnlich. Es gibt außerdem Varianten mit anderem Erscheinungsbild wie das lokalisierte BP. Der diagnostische Goldstandard ist die direkte Immunfluoreszenzmikroskopie einer periläsional entnommenen Hautbiopsie, welche lineare Ablagerungen von IgG und C3 an der Basalmembran zeigt. Vervollständigt wird die Diagnostik durch die indirekte Immunfluoreszenzmikroskopie sowie weiterführende ELISA-Untersuchungen, mittels derer zirkulierende Autoantikörper im Patientenserum nachgewiesen werden können. Das wichtigste Zielantigen ist BP180, ein hemidesmosomales, von Keratinozyten exprimiertes Protein. Ergänzend kann eine histopathologische Untersuchung erfolgen, die allerdings nur Hinweise zur Spaltebene und zum (meist Eosinophilen-dominierten) Infiltratmuster geben kann und alleine nicht zur Diagnosestellung ausreicht. Die Pathogenese des BP ist Gegenstand der wissenschaftlichen Diskussion. Medikamente wie Dipeptidylpeptidase-4-Inhibitoren können Auslöser sein; Assoziationen zu neurologischen Erkrankungen finden sich häufig. Entsprechend aktueller Leitlinien wird das BP mit topischen bzw. systemischen Glukokortikoiden ggf. in Kombination mit Doxyzyklin, Dapson oder einem Immunsuppressivum behandelt. Bei Therapieresistenz werden intravenöse Immunglobuline oder der anti-CD-20-Antikörper Rituximab eingesetzt. Aufgrund einer vergleichsweise hohen Mortalität bedingt durch Patientenalter und iatrogener Immunsuppression werden neue Therapieansätze gesucht. Fallserien, Kohortenanalysen und Phase 1-/2-Studien mit anti-IgE-Antikörpern und Inhibitoren der eosinophilen Granulozyten sowie des Komplementsystems zeigen teils vielversprechende Effekte. Die wichtigsten Vertreter der Pemphiguserkrankungen sind der Pemphigus vulgaris (PV), der Pemphigus foliaceus (PF) und der sehr seltene paraneoplastische Pemphigus (PNP). Klinisch präsentiert sich der PV mit meist enoralen Schleimhauterosionen und teilweise zusätzlichen Erosionen an der freien Haut. Der PF manifestiert sich nur an der freien Haut. Wie beim BP wird die Diagnose mittels direkter Immunfluoreszenzmikroskopie gestellt, welche beim PV und PF netzförmige Ablagerungen von IgG und C3 innerhalb der Epidermis zeigt. Die häufigsten Zielantigene sind die Desmogleine 1 und 3. Genetische Prädispositionen für den PV und PF sind bekannt und Grund für eine global unterschiedliche Häufigkeit. Der PNP ist immer mit einer malignen Erkrankung assoziiert und von einem progredienten Verlauf mit hoher Mortalität geprägt. Therapeutisch erfordern die Pemphiguserkankungen oft aggressivere Ansätze als das BP. Neben systemischen Glukokortikoiden und Immunsuppressiva wird für den PV und PF der anti-CD-20-Antikörper Rituximab empfohlen. Neue Therapieansätze sind die Hemmung der Bruton-Tyrosinkinase sowie des neonatalen Fc-Rezeptors (FcRN). In einer Phase 2-Studie zeigte Efgartigimod, ein Antagonist des FcRN, eine hohe Therapieeffektivität für Patienten mit PV und PF.

The role of human antigen R (HuR) in modulating proliferation, senescence and radiosensitivity of skin cells

The skin is the largest outermost organ of the human body. It is vulnerable to various damages, such as ionizing radiation. Exploration of proliferation, senescence and radiosensitivity of skin cells contributes to the development of medical and cosmetic countermeasures against skin aging and toward injury protection. Human antigen R (HuR) is one of the most widely studied RNA-binding proteins and serves an important role in stabilization of mRNA and regulation of the expression of the target genes. To investigate the role of HuR in modulating proliferation, senescence and radiosensitivity of skin cells, the present study performed an in vitro study using lentivirus-mediated overexpression or silencing of HuR in human keratinocyte HaCaT cells and human skin fibroblast WS1 cells. The results indicated that overexpression of HuR promoted proliferation, whereas downregulation of HuR inhibited proliferation of HaCaT and WS1 cells. Overexpression of HuR reduced apoptosis and senescence in skin cells. RNA-Seq of skin cells with HuR overexpression or knockdown identified 77 mRNAs positively or negatively correlated with HuR expression levels. In addition, silencing of HuR induced a significant increase in radiogenic reactive oxygen species after irradiation. Overexpression of HuR increased radiotolerance of HaCaT and WS1 cells. RNA immunoprecipitation coupled with RNA-Seq identified 14 mRNAs interacting with HuR upon radiation exposure. Overall, the findings of the present study illustrated the key role of HuR in modulating proliferation, senescence and radiosensitivity of skin cells providing a new therapeutic strategy for cosmetic treatments and to combat skin injury.

Deciphering the Contribution of BP230 Autoantibodies in Bullous Pemphigoid

Bullous pemphigoid (BP) is a subepidermal autoimmune blistering disease predominantly affecting elderly patients and carries significant morbidity and mortality. Patients typically suffer from severe itch with eczematous lesions, urticarial plaques, and/or tense blisters. BP is characterized by the presence of circulating autoantibodies against two components of the hemidesmosome, BP180 and BP230. The transmembrane BP180, also known as type XVII collagen or BPAG2, represents the primary pathogenic autoantigen in BP, whereas the intracellular BP230 autoantigen is thought to play a minor role in disease pathogenesis. Although experimental data exist suggesting that anti-BP230 antibodies are secondarily formed following initial tissue damage mediated by antibodies targeting extracellular antigenic regions of BP180, there is emerging evidence that anti-BP230 IgG autoantibodies alone directly contribute to tissue damage. It has been further claimed that a subset of patients has a milder variant of BP driven solely by anti-BP230 autoantibodies. Furthermore, the presence of anti-BP230 autoantibodies might correlate with distinct clinical features. This review summarizes the current understanding of the role of BP230 and anti-BP230 antibodies in BP pathogenesis.

Focus on the Contribution of Oxidative Stress in Skin Aging

Skin aging is one of the most evident signs of human aging. Modification of the skin during the life span is characterized by fine lines and wrinkling, loss of elasticity and volume, laxity, rough-textured appearance, and pallor. In contrast, photoaged skin is associated with uneven pigmentation (age spot) and is markedly wrinkled. At the cellular and molecular level, it consists of multiple interconnected processes based on biochemical reactions, genetic programs, and occurrence of external stimulation. The principal cellular perturbation in the skin driving senescence is the alteration of oxidative balance. In chronological aging, reactive oxygen species (ROS) are produced mainly through cellular oxidative metabolism during adenosine triphosphate (ATP) generation from glucose and mitochondrial dysfunction, whereas in extrinsic aging, loss of redox equilibrium is caused by environmental factors, such as ultraviolet radiation, pollution, cigarette smoking, and inadequate nutrition. During the aging process, oxidative stress is attributed to both augmented ROS production and reduced levels of enzymatic and non-enzymatic protectors. Apart from the evident appearance of structural change, throughout aging, the skin gradually loses its natural functional characteristics and regenerative potential. With aging, the skin immune system also undergoes functional senescence manifested as a reduced ability to counteract infections and augmented frequency of autoimmune and neoplastic diseases. This review proposes an update on the role of oxidative stress in the appearance of the clinical manifestation of skin aging, as well as of the molecular mechanisms that underline this natural phenomenon sometimes accelerated by external factors.

Comorbidities in Patients with Autoimmune Bullous Disorders: Hospital-Based Registry Study

The incidence of autoimmune bullous disorders has increased over the years, especially in elderly patients with multiple comorbidities, which has stimulated research into their association with other diseases. We performed a retrospective observational study used the Minimum Basic Data Set of hospital discharges to review records of patients admitted to Spanish public hospitals between 2016 and 2019 with a diagnosis of any autoimmune bullous disorder. The objectives were to describe the comorbidity profile and the clinical-epidemiological characteristics of patients with pemphigus and pemphigoid, and analyze the evolution of the incidence of these diseases. The study included 1950 patients with pemphigus and 5424 patients with pemphigoid. Incidence increased from 2016 to 2019. The main comorbidities were hypertension (40.19%) and diabetes mellitus (28.57%). Compared to patients with pemphigoid, those with pemphigus had a higher prevalence of neoplasms, osteoporosis, solid metastases and malignant lymphoma, while the prevalence of hypertension, kidney disease, diabetes, heart failure, dementia, chronic obstructive pulmonary disease and Parkinson’s disease was higher in the pemphigoid group (p < 0.05). Therefore, since autoimmune bullous disorders are associated with diverse comorbidities and their incidence has risen in recent years, the establishment of strategies to prevent the main comorbidities in these patients is justified.