Improving the Diagnosis of Dermatitis Herpetiformis Using the Intraepithelial Lymphogram

Dermatitis herpetiformis is a cutaneous manifestation of celiac disease. Phenotyping of intraepithelial lymphocytes in the small bowel mucosa can strengthen the diagnosis of celiac disease when it is not clear-cut. We aim to evaluate the usefulness of the intraepithelial lymphogram to confirm dermatitis herpetiformis in equivocal cases. We performed a retrospective multicenter study on patients diagnosed with dermatitis herpetiformis and collected data from the intraepithelial lymphogram assessed by flow cytometry. A total of 36 patients were analyzed in relation to the severity of intestinal damage (18 had non-atrophic mucosa) at baseline (N = 28) and/or after the adoption of a gluten-free diet (median follow-up of three years, N = 16). We observed that patients with atrophy more often had positive celiac serology (p = 0.019), celiac clinical symptoms (p = 0.018), and iron-deficiency anemia (p = 0.018), but the severity of skin damage was similar in both groups (p = 0.79). At baseline, increased TCRγδ+ cells were present in 94% of patients with atrophy and 67% with non-atrophic lesions (p = 0.13). After a gluten-free diet, increased TCRγδ+ cells persisted in 100% and 63% of cases, respectively (p = 0.21). We concluded that increased TCRγδ+ cells may be helpful in confirming the diagnosis of dermatitis herpetiformis in equivocal cases, even in patients who were started on a gluten-free diet.

Cutaneous Disorders Masking Celiac Disease: Case Report and Mini Review with Proposal for a Practical Clinical Approach

Celiac disease (CD) is an immune-mediated systemic gluten-related disorder characterized by a wide spectrum of intestinal and extra-intestinal manifestations, including damage to cutaneous and connective tissue. We report a rare case of chronic severe dermatitis involving connective tissue and cutaneous vascular vessels as the main clinical presentation of undiagnosed seronegative gluten disorder. A gluten-free diet dramatically improved the intestinal and cutaneous clinical damage in the patient. Pitfalls and the steps of differential diagnosis are described. We also review the literature regarding studies of CD and connective tissue diseases to extend the knowledge of these rare associations. We propose a practical diagnostic approach in suspected CD in autoimmune cutaneous disorders.

Incidence of Dermatitis Herpetiformis in Sweden 2005 to 2018: A Nationwide Retrospective Cohort Study

Dermatitis herpetiformis has been investigated in the past; however, only a limited number of studies have reported its incidence based on validated nationwide population-based registries. To address this gap, the aims of this study are to estimate the incidence of dermatitis herpetiformis in Sweden and to validate the National Patient Register (NPR) for diagnosis of dermatitis herpetiformis. A population-based open cohort study was conducted, including all patients diagnosed with dermatitis herpetiformis (International Classification of Diseases 10th revision; ICD-10 code L13.0) in Sweden from 2005 to 2018 (n = 1,724), identified from the NPR. The diagnosis of dermatitis herpetiformis in the NPR was validated using medical records, histopathological and immunopathological data, yielding a positive predictive value (PPV) of 62.5%. The mean annual incidence of dermatitis herpetiformis was 0.93/100,000 (95% confidence interval 0.79-1.08), female to male ratio 1:1, and mean age at diagnosis 60.9 years. In conclusion, this large nationwide cohort study showed a low validity for diagnosis of dermatitis herpetiformis in the NPR, and the adjusted incidence rate of dermatitis herpetiformis in Sweden was estimated to be 0.93/100,000, which is lower than that in previous Swedish studies.

Role of Human Leukocyte Antigen Class II in Antibody-Mediated Skin Disorders

HLA class II molecules are key factors determining susceptibility to autoimmune disorders, and their role in immune-mediated skin conditions such as psoriasis has been extensively investigated. However, there is currently little understanding of their role in antibody-mediated skin diseases such as autoimmune blistering disorders. We researched the available literature using PubMed to narratively review the current knowledge on HLA associations in antibody-mediated blistering skin pathologies. Our results summarized the risk alleles that are identified in the literature, together with certain known protective alleles: in the pemphigus group, alleles HLA-DQB1*0503 and HLA-DRB1*0402 are most commonly associated with disease; in the pemphigoid group, the most studied allele is HLA-DQB1*0301; in epidermolysis bullosa acquisita, few genetic studies are available; in dermatitis herpetiformis, the association with haplotypes HLA-DQ2 and HLA-DQ8 is strongly established; finally, in linear IgA bullous disease, specific HLA alleles may be responsible for pediatric presentations. Our current pathogenic understanding of this group of disorders assigns a key role to predisposing HLA class II alleles that are able to bind disease autoantigens and therefore stimulate antigen-specific autoreactive T cells. The latter engage B lymphocytes that will produce pathogenic autoantibodies. The distribution of HLA alleles and their disease associations are variable across demographics, and an in-depth pathogenetic understanding is needed to support associations between HLA alleles and disease phenotypes. Additionally, in a personalized medicine approach, the identification of HLA alleles associated with the risk of disease may become clinically relevant in identifying susceptible subjects that should avoid exposure to known triggers, such as medication, when possible.

Clinicopathological Profile of Dermatitis Herpetiformis Patients in Saudi Arabia

Objectives The aim of this study was to describe the clinical, serological, and histopathological features of patients with dermatitis herpetiformis (DH) in Saudi Arabia. Methods We retrospectively reviewed the medical charts of all patients diagnosed with DH in the dermatology departments of National Guard Health Affairs (NGHA) hospitals in five different cities, from 2016 to 2022. We included patients who had been diagnosed by a dermatologist and had a combination of typical DH skin lesions, positive immunoglobulin A (IgA) on direct immunofluorescence (DIF), and/or positive tissue transglutaminase (tTG) IgA. Results A total of 11 patients were included. Their average age was 43.6 ± 12.5 years, and the ratio of females: males was 2.7: 1. Among the eight skin biopsies performed, IgA was detected on DIF in five patients. Seven out of nine patients (77.8%) had positive tTG IgA. Nine patients were managed with dapsone and a gluten-free diet (GFD); they had excellent responses within months. Conclusion The profiles of Saudi patients with DH were similar to those of Caucasian patients, but DH appears to be less common in Saudi Arabia. The high positive rates of tTG IgA make it an important tool for diagnosis in unclear cases. Dermatitis herpetiformis is likely associated with underlying gluten-sensitive enteropathy in Saudi patients.

Separate Gut Plasma Cell Populations Produce Auto-Antibodies against Transglutaminase 2 and Transglutaminase 3 in Dermatitis Herpetiformis

Dermatitis herpetiformis (DH) is an inflammatory skin disorder often considered as an extra intestinal manifestation of celiac disease (CeD). Hallmarks of CeD and DH are auto-antibodies to transglutaminase 2 (TG2) and transglutaminase 3 (TG3), respectively. DH patients have auto-antibodies reactive with both transglutaminase enzymes. Here it is reported that in DH both gut plasma cells and serum auto-antibodies are specific for either TG2 or TG3 with no TG2-TG3 cross reactivity. By generating monoclonal antibodies from TG3-specific duodenal plasma cells of DH patients, three conformational epitope groups are defined. Both TG2-specific and TG3-specific gut plasma cells have few immunoglobulin (Ig) mutations, and the two transglutaminase-reactive populations show distinct selection of certain heavy and light chain V-genes. Mass spectrometry analysis of TG3-specific serum IgA corroborates preferential usage of IGHV2-5 in combination with IGKV4-1. Collectively, these results demonstrate parallel induction of anti-TG2 and anti-TG3 auto-antibody responses involving separate B-cell populations in DH patients.

Exploring Celiac Disease: A Case Analysis of Multi-Systemic Symptoms and Effective Dietary Intervention in a Young Female

This study presents the case of a 23-year-old woman diagnosed with celiac disease (CD), a condition triggered by an immune response to gluten, leading to inflammation in the small intestine. The patient manifested typical gastrointestinal symptoms, including diarrhea, abdominal pain, and vomiting, complemented by extra-intestinal signs such as fatigue and skin rashes. Diagnosis was corroborated through the presence of tTG-IgA antibodies and distinct histological changes in the duodenum. A notable finding was the patient's iron deficiency anemia, directly linked to the duodenal damage caused by CD. Effective management, encompassing a strict gluten-free diet and iron supplementation, resulted in marked improvement in her condition. This case accentuates the significance of early CD detection, especially in patients exhibiting a combination of gastrointestinal and extra-intestinal symptoms. Emphasis is placed on the pivotal role of timely diagnosis, adherence to a gluten-free regimen, and sustained monitoring to ensure patient well-being and prevent complications.

Patient-reported burden of skin disorders in coeliac disease

OBJECTIVES

The current knowledge on the associations between coeliac disease and different skin diseases is contradictory and the patient's perspective on the burden of these is lacking. This study aimed to investigate patient-reported frequency, severity and quality of life effects of skin disorders in coeliac disease patients compared to controls and moreover to study the impacts of gluten-free diet on these skin diseases.

MATERIALS AND METHODS

A study questionnaire designed for the purposes of this study and a validated Dermatology Life Quality Index (DLQI) questionnaire were posted to 600 adult members of the Finnish Coeliac Society and 1173 matched controls. Responses from 327 coeliac disease patients and 382 non-coeliac controls were compared.

RESULTS

Coeliac disease patients were shown to be at no increased risk of atopic dermatitis, acne, rosacea, psoriasis, alopecia areata, vitiligo or chronic urticaria. The severity of these skin diseases did not differ between study groups, but the risk for at least moderate effects on quality of life caused by dermatological diseases was increased among those with coeliac disease. Positive response from gluten-free diet was most commonly experienced by coeliac disease patients with atopic dermatitis.

CONCLUSIONS

Even though the risk for skin diseases was shown not to be increased among coeliac disease patients, there is still an increased burden related to experienced skin symptoms among these patients, which non-dermatologists treating coeliac disease patients should acknowledge.

Skin gluten-related disorders: new and old cutaneous manifestations to be considered

The term gluten-related disorders (GRD) refer to a spectrum of different clinical manifestations triggered by the ingestion of gluten in genetically susceptible individuals, including coeliac disease (CD), wheat allergy and non-celiac gluten sensitivity (NCGS). GRD are characterized by a large variety of clinical presentations with both intestinal and extra-intestinal manifestations. The latter may affect almost every organ of the body, including the skin. Besides the well-known association between CD and dermatitis herpetiformis, considered as the cutaneous specific manifestation of CD, many other muco-cutaneous disorders have been associated to GRD. In this review, we analyzed the main features of dermatological diseases with a proven association with GRD and those that improve after a gluten-free diet, focusing on the newly described cutaneous manifestations associated with NCGS. Our main hypothesis is that a "cutaneous-gluten sensitivity," as specific cutaneous manifestation of NCGS, may exist and could represent a diagnostic marker of NCGS.

Atypical Dermatitis Herpetiform and Scalp Psoriasis in Ulcerative Colitis Patient Treated With Adalimumab

Adalimumab is a blocker of tumor necrosis factor (TNF)-alpha with established efficacy in the treatment of ulcerative colitis. However, literature indicated that adalimumab can, occasionally, induce paradoxical psoriasis reactions and, very rarely, dermatitis herpetiformis. We present a unique case of a 26-year-old female patient who developed a combination of dermatitis herpetiformis and scalp psoriasis paradoxically as a result of adalimumab treatment for ulcerative colitis. To the best of our knowledge, this is the first case of such a combination within the context of adalimumab therapy. The etiopathological underpinning of such a reaction remains elusive but is speculated to be complex and involves the interaction of several immunological and dermatological mechanisms. Adalimumab therapy is associated with a genuine risk for the development of paradoxical psoriasis and dermatitis herpetiformis. We, through this case report, added to the evidence confirming such an association. Clinicians should follow these potential adverse effects and make every effort to warn patients of their likelihood.

Immunopathological Assessment of the Oral Mucosa in Dermatitis Herpetiformis

Dermatitis herpetiformis (Duhring's disease, DH) is a chronic blistering cutaneous condition with pruritic polymorphic lesions, consisting of vesicles, papules or nodules and erythema, found predominantly on the extensor surfaces of the limbs, buttocks, and neck. Diagnosis is based on characteristic clinical and immunopathological findings. Oral manifestations of DH have rarely been described. The aim of the study was to evaluate IgA, IgG, IgM and C3 complement deposits in the oral mucosa in DH patients. Direct immunofluorescence (DIF) was performed on the oral mucosa specimens collected from 10 DH patients. Biopsy was taken in a local anesthesia from perilesional site from the buccal mucosa and then preserved in a standard procedure using polyclonal rabbit IgG, IgA, IgM and C3 antibodies. Granular IgA and C3 deposits were found in 6 patients (60%), and in 3 subjects (30%) the result was indeterminate. Significant fluorescence of the deposits along the basement membrane was observed in 2 patients, moderate fluorescence in 3 patients, and in 4 cases the result was indeterminate. C3 deposits were found in 5 subjects (50%), 3 of them being moderate and 2 indeterminate. No IgM and IgG deposits were detected in the collected buccal mucosa specimens.

A Rare Case of COVID-19-Induced Acute Exacerbation of Oral Dermatitis Herpetiformis in a Geriatric Patient

Introduction

Dermatitis herpetiformis (DH) is an autoimmune vesiculobullous disease associated with celiac enteropathy. The clinical manifestation of DH is the occurrence of a papulovesicular rash on the skin. Oral mucosal involvement in DH is very rare. This study aimed to describe the impact of COVID-19 on the acute exacerbation of oral dermatitis herpetiformis.

Case Report

A 74-year-old woman was referred to the Oral Medicine Department with a chief complaint of the blisters on the skin for a week and ulcers in the oral cavity appeared two days ago. Extraoral examination revealed crusts on the neck and extremities. The lips appeared dry and desquamative. Intraoral examination revealed erosive lesions covered with a white-yellowish plaques on the right and left sides of the buccal mucosa, an ulcer with a diameter of 0.5 cm, and purpura hemorrhagic on left buccal mucosa and right lateral border of the tongue. Histopathological examination of the skin lesion revealed a subepithelial blister with eosinophils and neutrophil cells. The definitive diagnosis of dermatitis herpetiformis was made. She was given 5 mg intravenous dexamethasone, cetirizine 10 mg, and clindamycin 300 mg by the dermatologist. We gave hyaluronic acid 0.025% mouthwash for oral ulcers and petroleum jelly for the lips. The oral lesions had significant improvement after 4 weeks of treatment. Two months later, the patient experienced acute exacerbation after being infected with COVID-19 (anti-SARS-CoV-2 IgG S-RBD >40,000 AU/mL). The oral lesions healed after a month of treatment.

Conclusion

COVID-19 can trigger the acute exacerbation of dermatitis herpetiformis. SARS-CoV-2 causes an immune dysregulation and hypersensitivity reaction.

The risk of renal comorbidities in celiac disease patients depends on the phenotype of celiac disease

BACKGROUND

An increased risk of kidney disease in patients with celiac disease has been reported, but the association has remained obscure. Only few studies have investigated the association between renal comorbidities and dermatitis herpetiformis, a cutaneous manifestation of celiac disease.

OBJECTIVES

We investigated whether patients with different phenotypes of celiac disease are at higher risk of kidney diseases than age- and sex-matched references.

METHODS

The diagnoses of glomerulonephritis, diabetic nephropathy, interstitial nephritis, and end-stage renal disease obtained from the National Hospital Discharge Register between 1970 and 2015 were identified in celiac disease (Marsh III, n = 1072) and dermatitis herpetiformis (n = 368) patients diagnosed at Tampere University Hospital catchment region and in 4296 reference subjects. Using the Cox proportional hazards model, we compared the risk of kidney diseases between patients and references. The study protocol was approved by the Regional Ethics Committee of Tampere University Hospital (R16090). As the study was register based, no consent from patients was required.

RESULTS

Even after adjusting for type 1 diabetes, celiac disease was associated with an elevated risk of kidney disease (hazard ratio [HR] 1.85, 95% confidence interval [CI] 1.12-3.03), glomerulonephritis (HR 3.37, 95% CI 1.64-6.95), and IgA nephropathy (IgAN) (HR 18.98, 95% CI 2.29-157.63). No similarly elevated risk was found among dermatitis herpetiformis patients (HR 1.50, 95% CI 0.63-3.55; HR 2.21, 95% CI 0.77-6.38; and HR 5.87, 95% CI 0.53-64.79, respectively).

CONCLUSION

Celiac disease patients were at increased risk of kidney diseases, notably IgAN. The risk was dependent on the celiac disease phenotype and was not seen in patients with dermatitis herpetiformis. Awareness of possible renal manifestations is recommended when treating celiac disease patients.

Histopathology of autoimmune bullous dermatoses: What's new?

Autoimmune bullous dermatoses are characterized by the presence of tissue-bound and often circulating pathogenic autoantibodies targeting structural components of the skin and/or mucous membranes. The diagnostic workup for this heterogeneous group of disorders consists of a multi-step process, of which the light microscopic examination is a crucial component. This review is organized following a classification scheme that is based on two main histopathologic features, namely level of intraepithelial split and composition of the inflammatory infiltrate. Overall, we aim to place emphasis on the histopathologic clues that can assist pathologists in differential diagnosis and review the updates in the literature.

Current and Innovated Managements for Autoimmune Bullous Skin Disorders: An Overview

Autoimmune bullous skin disorders are a group of disorders characterized by the formation of numerous blisters and erosions on the skin and/or the mucosal membrane, arising from autoantibodies against the intercellular adhesion molecules and the structural proteins. They can be classified into intraepithelial or subepithelial autoimmune bullous dermatoses based on the location of the targeted antigens. These dermatoses are extremely debilitating and fatal in certain cases, depending on the degree of cutaneous and mucosal involvement. Effective treatments should be implemented promptly. Glucocorticoids serve as the first-line approach due to their rapid onset of therapeutic effects and remission of the acute phase. Nonetheless, long-term applications may lead to major adverse effects that outweigh the benefits. Hence, other adjuvant therapies are mandatory to minimize the potential harm and ameliorate the quality of life. Herein, we summarize the current therapeutic strategies and introduce promising therapies for intractable autoimmune bullous diseases.

Antibody Responses to Transglutaminase 3 in Dermatitis Herpetiformis: Lessons from Celiac Disease

Dermatitis herpetiformis (DH) is the skin manifestation of celiac disease, presenting with a blistering rash typically on the knees, elbows, buttocks and scalp. In both DH and celiac disease, exposure to dietary gluten triggers a cascade of events resulting in the production of autoantibodies against the transglutaminase (TG) enzyme, mainly TG2 but often also TG3. The latter is considered to be the primary autoantigen in DH. The dynamics of the development of the TG2-targeted autoimmune response have been studied in depth in celiac disease, but the immunological process underlying DH pathophysiology is incompletely understood. Part of this process is the occurrence of granular deposits of IgA and TG3 in the perilesional skin. While this serves as the primary diagnostic finding in DH, the role of these immunocomplexes in the pathogenesis is unknown. Intriguingly, even though gluten-intolerance likely develops initially in a similar manner in both DH and celiac disease, after the onset of the disease, its manifestations differ widely.

NUTRITION AND BULLOUS DISEASES

Although relatively uncommon, autoimmune bullous diseases carry the risk of increased mortality and can significantly impact quality of life. This group of diseases is broad and encompasses subepidermal conditions like bullous pemphigoid, cicatricial pemphigoid, epidermolysis bullosa acquisita, dermatitis herpetiformis, and linear IgA bullous dermatosis, as well as intraepidermal conditions like pemphigus and its variants. The pathophysiology of each condition is incompletely understood but broadly involves the formation of autoantibodies targeting skin adhesion proteins, a process which relies on a complex interplay between a dysregulated immune system, genetic predisposition, and environmental factors. We review the impact of nutrition on pathogenesis, clinical course, and treatment of various autoimmune bullous diseases.

[Stiff person syndrome associated with dermatitis herpetiformis: a case report]

Le syndrome de la personne raide (SPR) est une maladie rare affectant le système nerveux central et qui peut être d´origine auto-immune, paranéoplasique ou idiopathique. Sa présentation classique typique est caractérisée par une rigidité progressive du tronc et des membres, associée à des spasmes. Le diagnostic est soutenu par l'existence d'une activité musculaire continue et spontanée en détection à l'électroneuromyogramme, la présence d'anticorps anti-acide glutamique décarboxylase (anti-GAD) sériques, et une réponse aux benzodiazépines. Nous rapportons le cas d'un patient de 46 ans ayant une forme classique de syndrome de la personne raide auto-immune associée à une dermatite herpétiforme.

Frequency of Cutaneous Disorders in Patients With Celiac Disease

Background and objective

Celiac disease is an autoimmune multisystem disorder that is triggered by dietary gluten sensitivity in genetically susceptible individuals. It presents with extraintestinal cutaneous manifestations including dermatitis herpetiformis (DH), atopic dermatitis, psoriasis, urticaria, and alopecia areata. Due to the insufficient availability of data, this study aimed to estimate the frequency of cutaneous manifestation in a Pakistani population with celiac disease.

Methods

This cross-sectional study was conducted from January 2020 to July 2021, and 300 patients with a confirmed diagnosis of celiac disease were enrolled in the study from the internal medicine department of a tertiary care hospital in Pakistan. Celiac disease was confirmed by the presence of immunoglobulin A (IgA) endomysial antibody and IgA tissue transglutaminase antibody. The presence of cutaneous manifestations was assessed with the assistance of a qualified dermatologist and noted in a self-structured questionnaire.

Results

Overall, the most common cutaneous manifestation was DH (16.0%), whereas the second most common cutaneous manifestation was psoriasis (13.8%). DH was most commonly found among males (18.9%), while psoriasis was more common among females (14.12%).

Conclusion

Among the various cutaneous presentations in patients with celiac disease, the most common dermatological manifestation was DH. Therefore, patients with cutaneous manifestations should undergo screening for celiac disease.

Persistent Skin Symptoms after Diagnosis and on a Long-term Gluten-free Diet in Dermatitis Herpetiformis

Dermatitis herpetiformis is a cutaneous manifestation of coeliac disease treated with a gluten-free diet. However, the itching and blistering rash alleviates slowly after gluten withdrawal and occasionally persists despite a long-term gluten-free diet. This study investigated the prevalence and factors associated with prolonged (i.e. > 2 years) and ongoing skin symptoms in 237 patients with dermatitis herpetiformis. Data were gathered from medical records and via questionnaires. Among patients with dermatitis herpetiformis, 38% had prolonged symptoms after diagnosis, and 14% had ongoing skin symptoms at follow-up (median duration of gluten-free diet 24 years). A severe rash at diagnosis was associated with both prolonged and ongoing cutaneous symptoms. In addition, patients with dermatitis herpetiformis with ongoing skin symptoms at follow-up had been on the dietary treatment for a shorter time (median duration 16 vs 25 years) and were less often on a strict diet (53% vs 78%) compared with patients with dermatitis herpetiformis without ongoing skin symptoms.

Dermatitis Herpetiformis: An Update on Diagnosis, Disease Monitoring, and Management

Dermatitis herpetiformis (DH), Duhring disease, is caused by gluten sensitivity and affects 11.2 to 75.3 per 100,000 people in the United States and Europe with an incidence of 0.4 to 3.5 per 100,000 people per year. DH is characterized by a symmetrical blistering rash on the extensor surfaces with severe pruritus. The diagnosis continues to be made primarily by pathognomonic findings on histopathology, especially direct immunofluorescence (DIF). Recently, anti-epidermal transglutaminase (TG3) antibodies have shown to be a primary diagnostic serology, while anti-tissue transglutaminase (TG2) and other autoantibodies may be used to support the diagnosis and for disease monitoring. Newly diagnosed patients with DH should be screened and assessed for associated diseases and complications. A gluten-free diet (GFD) and dapsone are still mainstays of treatment, but other medications may be necessary for recalcitrant cases. Well-controlled DH patients, managed by a dermatologist, a gastroenterologist, and a dietician, have an excellent prognosis. Our review comprehensively details the current diagnostic methods, as well as methods used to monitor its disease course. We also describe both the traditional and novel management options reported in the literature.

Evaluation of a Bi-Analyte Immunoblot as a Useful Tool for Diagnosing Dermatitis Herpetiformis

Immune responses to tissue transglutaminase (tTG) and nonapeptides of gliadin (npG) are associated with dermatitis herpetiformis (DH), a gluten-related dermatosis. Recently, a bi-analyte immunoblot (b-aIB) was introduced to detect IgA antibodies in response to tTG and npG. We compared the utility of ELISA and b-aIB with tTG in serological diagnoses of DH and their agreement with direct immunofluorescence (DIF). In total, 55 sera (27 DIF-positive DH patients, 4 DIF-negative DH patients and 24 healthy controls) were examined. ELISA for anti-tTG IgA, b-aIB for anti-npG and anti-tTG IgA, and statistical analysis were performed. The b-aIB with tTG showed 78% sensitivity, 100% specificity, 100% positive predictive value, and 82% negative predictive value in relation to ELISA. A better rate of agreement (Cohen’s kappa values) in IgA detection was observed in the pair tTG ELISA and b-aIB with npG (0.85) than in pairs tTG ELISA and b-aIB with tTG (0.78) or b-aIB with tTG and b-aIB with npG (0.78). No degree of agreement was found between serological tests and DIF. Both serological tests may be used to detect the anti-tTG IgA in DH patients. Still, DH diagnosing requires careful consideration of clinical data as well as results of tissue imaging (crucial DIF) and immunoserological techniques detecting DH-type features.

The many-faced gluten sensitivity: Gluten-induced autoimmunity from dermatological point of view

Összefoglaló. A glutén, alimentáris környezeti antigénként, különböző szervrendszereket érintő autoimmun betegségeket tud kiváltani. A kórképek hátterében a gluténtolerancia veleszületett hiánya vagy az élet során bekövetkező elvesztése áll. A gluténindukált autoimmun betegségek között a leggyakoribb a coeliakia, melyet különböző súlyosságú enteropátia jellemez, és melynek a szöveti, 2-es típusú transzglutamináz az autoantigénje. A coeliakia extraintestinalis tünetei között azonban néha olyan bőr- és idegrendszeri kórképek jellegzetességei is megtalálhatók, melyek hátterében további transzglutamináz-autoimmunitás kialakulása áll. Idesorolható a hevesen viszkető, polimorf autoimmun bőrbetegség, a dermatitis herpetiformis (transzglutamináz-3-autoimmunitás) és a centrális és/vagy perifériás neurológiai károsodások egy jellegzetes csoportja (transzglutamináz-6-autoimmunitás). Az indukált autoimmunitás reverzibilis, a szigorúan tartott gluténmentes diéta mellett a coeliakia és a bőrtünetek elmúlnak, de az idegrendszeri tünetek egy része maradandó. Az elmúlt évtizedben beszámoltak gluténérzékeny, transzglutamináz-6-pozitív, nem coeliakiás (transzglutamináz-2-negatív) betegekről is. A gluténszenzitivitás sokféle megjelenését ma is erősen kutatják. Fontos a korai felismerés és a kórképek interdiszciplináris szemléletű kezelése. A coeliakia családi szűrővizsgálatokkal való korai felismerése és a tünetmentes egyének diétás kezelése is nagy jelentőségű a gluténérzékenység által kiváltott hiányállapotok és a társuló egyéb betegségek kialakulásának megelőzésében. Orv Hetil. 2021; 162(28): 1107-1118. Summary. Autoimmune diseases induced by digestion of gluten, an environmental antigen, can affect different organ systems. The diseases develop in individuals with congenital or acquired loss of gluten tolerance for life. Amongst the gluten-induced autoimmune diseases, celiac disease is the most common one, characterized by an enteropathy of varying severity. Here the target autoantigen is tissue (type 2) transglutaminase. While the extraintestinal manifestations of celiac disease are complex, they may include characteristics of certain skin and nervous system disorders that develop due to additional transglutaminase autoimmunities. Such diseases are the severely pruritic, polymorphic autoimmune skin disease, dermatitis herpetiformis due to epidermal (type 3) transglutaminase autoimmunity, and a distinctive group of gluten-sensitive neuropathies with central and/or peripheral neurological involvement caused by type 6 transglutaminase autoimmunity. While the celiac and skin autoimmune diseases gradually get into remission under a strict gluten-free diet, some neurological symptoms may persist. In the last decade, gluten-induced transglutaminase 6 positive but non-celiac (transglutaminase 2 negative) patients were reported. Today, various manifestations of gluten sensitivity are under extensive research. Early detection and interdisciplinary treatment of these disorders are important. Family screenings are of particular relevance in early recognition and dietary treatment of latent disease forms in order to prevent enteropathy-induced, malabsorption-related and other associated co-morbidities. Orv Hetil. 2021; 162(28): 1107-1118.

Morphological Spectrum of Vesiculobullous Skin Lesions: An Institutional Perspective

Introduction

A vesiculobullous lesion of the skin encompasses a group of dermatological disorders with protean clinicopathological features. They usually occur as a part of the spectrum of various infectious, inflammatory, drug-induced, genetic, and autoimmune disorders. Therefore, accurate diagnosis of these lesions is essential for appropriate management and to reduce the associated morbidity and mortality. The conventional skin punch biopsy is the mainstay in the diagnosis of dermatological diseases, especially when combined with confirmatory tests, such as direct immunofluorescence (DIF). Our study evaluated the clinicopathological spectrum of vesiculobullous lesions.

Methods

We studied 150 cases of vesiculobullous lesions at the Department of Histopathology, Liaquat National Hospital and Medical College Karachi, Pakistan. Written and informed consent was taken from the patients followed by skin punch procedure in which three biopsies were obtained, which included one biopsy from the lesion and two peri-lesional biopsies. One peri-lesional biopsy was sent in cryomatrix for DIF studies, whereas the other two were sent in formalin to follow the standard tissue-processing protocol.

Results

Our results showed that most patients belonged to the geriatric age group of more than 50 years (44.7%), and 54.7% of the patients were females. Total 74.7% of the patients had generalized lesions, followed by lower limbs (9.3%) and trunk (7.3%) involvement. Most patients were diagnosed with bullous pemphigoid (31.3%), followed by pemphigus vulgaris (27.3%), dermatitis herpetiformis (15.3%), Darier’s disease (14.7%), pemphigus foliaceus (4.7%), epidermolysis bullosa (2%), linear immunoglobulin A dermatosis (2%), paraneoplastic pemphigus (0.7%), and drug reactions (0.7%). DIF studies were applied on 60 cases, out of which complement protein C3c was the most commonly deposited protein (53.3%).

Conclusion

Our study emphasized the diagnostic role of skin punch biopsy in the proper evaluation of vesiculobullous skin lesions. Histopathology is the cornerstone diagnostic tool in this regard, with DIF being a useful adjunct.

Immunobullous disease

Immunobullous diseases are blistering cutaneous disorders that are caused by pathogenic antibodies binding to protein targets within the skin. There are a range of immunobullous disorders with characteristic morphology that relates to the structural properties of the target protein. In this article we will describe the pathogenesis, clinical features and treatment of the most common immunobullous disorders.

In vitro diagnostics for the medical dermatologist. Part I: Autoimmune tests

Despite the expansion of available in vitro laboratory tests at a rate far exceeding that of dermatologic pharmaceuticals, the existing literature is dominated by discussion of the latter. With the advent of numerous new tests, it can be difficult for practicing dermatologists to stay up-to-date on the available options, methodologies, and recommendations for when to order one test over another. Understanding the inherent strengths and weaknesses of these options is necessary to inform appropriate ordering and proper interpretation of the results. The first article in this continuing medical education series summarizes information on methodology, test characteristics, and limitations of several in vitro laboratory tests used for the work up of undifferentiated patients suspected of having dermatologic autoimmune diseases and it provides a general guide to ordering these tests.

Missing Insight Into T and B Cell Responses in Dermatitis Herpetiformis

Dermatitis herpetiformis is a cutaneous form of celiac disease manifesting as an itching rash typically on the elbows, knees and buttocks. It is driven by the ingestion of gluten-containing cereals and characterized by granular deposits of immunoglobulin A in the papillary dermis. These antibodies target transglutaminase (TG) 3 and in the majority of patients they are also found in circulation. The circulating antibodies disappear and skin symptoms resolve as a result of gluten-free diet but the cutaneous anti-TG3 IgA deposits may persist for several years. In dermatitis herpetiformis, plasma cells secreting antibodies against TG3 are located in the intestinal mucosa similarly to those producing TG2 antibodies characteristic for celiac disease. In fact, both TG2- and TG3-specific plasma cells and gluten responsive T cells are found in dermatitis herpetiformis patients but the interplay between these cell populations is unknown. The small bowel mucosal damage in celiac disease is believed to be mediated by co-operation of cytotoxic intraepithelial T cells and the inflammatory milieu contributed by gluten-reactive CD4+ T cells, whereas the skin lesions in dermatitis herpetiformis appear to be devoid of gluten reactive T cells. Thus, how celiac disease-type intestinal T and B cell responses develop into an autoimmune condition affecting the skin is still incompletely understood. Finally, the skin and small bowel lesions may reappear upon reintroduction of gluten in patients treated with gluten-free diet but virtually nothing is known about the long-lived B cell and memory T cell populations activating in response to dietary gluten in dermatitis herpetiformis.

Subepithelial autoimmune bullous dermatoses disease activity assessment and therapy

Subepidermal (subepithelial) autoimmune blistering dermatoses are a group of rare skin disorders characterized by the disruption of the dermal-epidermal junction through the action of autoantibodies. The fourth article in this continuing medical education series presents the current validated disease activity scoring systems, serologic parameters, treatments, and clinical trials for bullous pemphigoid, mucous membrane pemphigoid, epidermolysis bullosa acquisita, bullous systemic lupus erythematosus, anti-p200 pemphigoid, linear IgA bullous dermatosis, and dermatitis herpetiformis.

Subepithelial autoimmune blistering dermatoses: Clinical features and diagnosis

Subepithelial autoimmune blistering dermatoses are a group of rare skin disorders that are characterized by the disruption of the dermal-epidermal junction through the action of autoantibodies. The third article in this continuing medical education series explores the background, epidemiology, clinical features, and diagnostic criteria of each of the major subepithelial autoimmune blistering dermatoses, including bullous pemphigoid, pemphigoid gestationis, lichen planus pemphigoides, mucous membrane pemphigoid, linear IgA bullous dermatosis, and dermatitis herpetiformis.

Educational Case: Dermatitis Herpetiformis

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.1.

Mast cells and thymic stromal lymphopoietin (TSLP) expression positively correlates with pruritus intensity in dermatitis herpetiformis

BACKGROUND

Pruritus is one of the leading symptoms of dermatitis herpetiformis (DH), however, studies on the pathogenesis of pruritus are scarce. Currently, skin mast cells (MCs) have been indicated to play a role in pruritus in autoimmune bullous disease.

OBJECTIVE

To study the role of mast cells and related mediators involved in the pathogenesis of pruritus in DH.

MATERIALS & METHODS

The number of MCs and expression of histamine and thymic stromal lymphopoietin (TSLP) was investigated in lesions of 29 DH cases and 15 healthy skin donors by immunohistochemistry. Fourteen patients were assessed for severity of pruritus based on the Numeric Rating Scale and Pruritus Grading System. The levels of histamine and TSLP in the serum of 18 DH patients and 15 healthy controls were also investigated.

RESULTS

A significant increase in the number of MCs and degranulation was observed in DH lesions, which positively correlated with intensity of pruritus. In addition, skin TSLP but not histamine was shown to correlate with intensity of pruritus. No significant difference in expression of serum TSLP or histamine was observed between DH patients and healthy controls.

CONCLUSION

These results suggest that skin MCs and TSLP might be involved in the pathogenesis of pruritus in DH which should be further clarified in future studies.

Autoantibodies Against the Immunodominant Bullous Pemphigoid Epitopes Are Rare in Patients With Dermatitis Herpetiformis and Coeliac Disease

Dermatitis herpetiformis (DH) is an extraintestinal manifestation of coeliac disease (CD). Patients with DH have an elevated risk of development of another autoimmune blistering skin disease, bullous pemphigoid (BP). In this study we investigated whether patients with DH and CD (mean age for both 49 years) have circulating autoantibodies against BP180, the major BP autoantigen. ELISA tests showed that only a few DH (3/46) and CD (2/43) patients had BP180-NC16A IgG autoantibodies. Immunoblotting found that more than half of the DH samples contained IgG autoantibodies against full-length BP180. Epitope mapping with 13 fusion proteins covering the BP180 polypeptide revealed that in DH and CD patients, IgG autoantibodies did not target the NC16A or other epitopes typical of BP but recognized other intracellular and mid-extracellular regions of BP180. None of the analyzed DH and CD patients with either ELISA or immunoblotting positivity had IgG or IgA reactivity against the cutaneous basement membrane in indirect immunofluorescence analysis or skin symptoms characteristic of BP. Although only a minority of middle-aged DH patients had IgG autoantibodies against the immunodominant epitopes of BP180, our results do not exclude the possibility that intermolecular epitope spreading could explain the switch from DH to BP in elderly patients.

TG6 Auto-Antibodies in Dermatitis Herpetiformis

Dermatitis herpetiformis (DH) is an extraintestinal manifestation of gluten sensitivity, in which an autoimmune response is directed against transglutaminase 3 (TG3), an epidermal transglutaminase. TG2 is the autoantigen in celiac disease (CD), defined by the presence of enteropathy, and TG6 is the autoantigen in neurological manifestations of gluten sensitivity. The interplay between B cell responses to these 3 transglutaminases in developing the clinical spectrum of disease manifestations is not completely understood. Also, the individual or combined diagnostic and predictive value of the respective autoantibodies is not fully explored. We examined the prevalence of TG6 antibodies in a cohort of patients with DH. TG6 positivity was found in 13/33 (39%), with IgA detected in 11 patients, IgG in 3, and both in 1. This was significantly higher compared to what is seen in the classic CD cases (14%) in a Finnish population. TG6 positive baseline samples constituted 60% of DH patients with no enteropathy (n = 10), as opposed to 17% positivity in those with overt enteropathy (n = 12; Marsh IIIB). Repeat testing after adherence to a gluten-free diet for 1 year showed reduced titers for TG6 antibodies in 11/13 (85%), whereby 7 patients were now TG6 antibody-negative. Four patients seroconverted and tested positive for TG6 antibodies at one year, due to the ongoing exposure to gluten. We report another patient who presented with neurological manifestations (encephalopathy) leading to the diagnosis of CD, who was intermittently adhering to a gluten-free diet. Serological testing at baseline showed him to be positive for antibodies to all 3 transglutaminases. Eleven years later, he developed DH. He also subsequently developed ataxia and peripheral neuropathy. Although TG3 and TG6 autoantibodies are linked to certain disease manifestations, TG2, TG3, and TG6 autoantibodies can be present across the spectrum of GRD patients and might develop years before onset of symptoms of extraintestinal manifestations. This is consistent with gluten-dependent adaptive immunity being a necessary but not sufficient pretext to organ-specific damage. TG6 antibodies appear to develop more frequently in patients where tolerance to gluten was broken but, either there was no development of the molecular state driving the tissue destruction at the level of the gut, or perhaps more likely, there was more resistance to developing this phenotype.

The Long-Term Safety and Quality of Life Effects of Oats in Dermatitis Herpetiformis

The treatment of choice for dermatitis herpetiformis (DH), a cutaneous manifestation of coeliac disease, is a life-long gluten-free diet (GFD). In a GFD, wheat, rye and barley should be strictly avoided, but the role of oats is more controversial. This study aimed to investigate the safety and long-term quality of life and health effects of oat consumption in 312 long-term treated DH patients. Baseline data were gathered from patient records and follow-up data from questionnaires or interviews, and validated questionnaires were used to assess quality of life. We found that altogether 256 patients (82%) were consuming oats as part of their GFD at the follow-up. Long-term follow-up data showed that there were no differences in the presence of long-term illnesses, coeliac disease complications or the usage of medication between those consuming and not consuming oats. However, oat consumers had a better quality of life and reported ongoing gastrointestinal symptoms less frequently (4% vs 19%, p = 0.004) at the follow-up than those not consuming oats. The study established that oats are safe for DH patients and in the long-term seem to improve the quality of life of DH patients.

Intestinal TG3- and TG2-Specific Plasma Cell Responses in Dermatitis Herpetiformis Patients Undergoing a Gluten Challenge

Dermatitis herpetiformis (DH), a cutaneous manifestation of coeliac disease, is characterized by transglutaminase (TG) 3-targeted dermal immunoglobulin A (IgA) deposits. The treatment for DH is the same as for coeliac disease, namely a life-long gluten-free diet. DH patients typically have gluten-dependent circulating autoantibodies targeting TG3 and TG2, and plasma cells secreting such autoantibodies have been detected in the small intestinal mucosa. This study investigates the gluten-responsiveness of intestinal TG3 and TG2 antibody-secreting plasma cells in 16 treated DH patients undergoing a gluten challenge. The frequency of both plasma cell populations increased significantly during the challenge, and their frequency correlated with the corresponding serum autoantibody levels at post-challenge. TG3-specific plasma cells were absent in all 18 untreated coeliac disease patients and seven non-coeliac control subjects on gluten-containing diets. These findings indicate that, in DH, both intestinal TG3- and TG2-antibody secreting plasma cells are gluten-dependent, and that TG3-antibody secreting plasma cells are DH-specific.

Current Concepts of Dermatitis Herpetiformis

Dermatitis herpetiformis (DH) is an autoimmune skin disease that causes itchy, blistering rash, typically on the elbows, knees and buttocks. DH and coeliac disease share the same genetic background, glutendependent enteropathy and antibody response against tissue transglutaminase. DH is currently considered a cutaneous manifestation of coeliac disease, and the prevailing hypothesis is that DH develops as a late manifestation of subclinical coeliac disease. The incidence of DH is decreasing contemporarily with the increasing incidence of coeliac disease. The IgA immune response in DH skin is directed against epidermal transglutaminase, while the autoantigen in the gut is tissue transglutaminase. Granular IgA deposition in the papillary dermis is pathognomonic for DH, and is a finding used to confirm the diagnosis. The treatment of choice for DH is a life-long gluten-free diet, which resolves the rash and enteropathy, increases quality of life, and offers a good long-term prognosis.

Fibrillar-type dermatitis herpetiformis

Dermatitis herpetiformis (DH) is a pruritic papulovesicular disease that is relatively common in Caucasian populations, and was first reported by Louis Duhring. It is characterized by granular IgA deposition in the dermal-epidermal junction and gluten-sensitive enteropathy (GSE) associated with human leukocyte antigen-DQ2/DQ8 haplotype. In contrast, DH is rare in Japan, and Japanese DH patients occasionally show unique features, including a high frequency of fibrillar IgA deposition in the papillary dermis, and rare occurrence of GSE. We refer to this condition in Japanese patients as "fibrillar-type DH", while the DH that is typically observed in the Caucasian population is referred to as "granular-type DH". In patients with typical fibrillar-type DH, IgA antibodies to epidermal transglutaminase are the only antibodies detected. In addition, Th2-type cytokines, such as interleukin (IL)-4, IL-5 and IL-13, may be important in the development of skin lesions in fibrillar-type DH (especially in the infiltration of tissue by eosinophils), as in granular-type DH. The pathogenesis of fibrillar-type DH may differ from that of granular-type DH, which is dependent on gluten and in which IgA antibodies to tissue transglutaminase (the main antigen in GSE) are detected. We herein review the clinical, histological, and immunological findings of fibrillar-type DH.

An update on direct immunofluorescence for diagnosing dermatitis herpetiformis

This mini-review presents an update on the direct immunofluorescence (DIF) for diagnosing dermatitis herpetiformis. The DIF of uninvolved, perilesional skin is a crucial laboratory procedure in diagnosing dermatitis herpetiformis (DH). IgA deposits at the dermal-epidermal junction (DEJ) of perilesional skin with DIF can also be found in coeliac patients with inflammatory skin diseases different from DH. In certain patients presenting with the rash resembling DH, the deposition of exclusively C3 at DEJ can be found. The term "granular C3 dermatosis" was proposed to name such a rash. Recent data on DH suggest that perhaps the very concept of DH that we are universally accepting now is misleading and should be revised.

Sulfasalazine-induced generalized vitiligo in a patient with dermatitis herpetiformis and celiac disease

Vitiligo is an acquired idiopathic pigmentary skin disorder characterized by the development of white macules and patches due to the loss of functioning melanocytes. In this report, we describe a case of a patient with a longstanding history of dermatitis herpetiformis (DH) and celiac disease that developed rapidly progressing, biopsy-confirmed generalized vitiligo after 11 months of treatment with anti-inflammatory medication sulfasalazine, prescribed for the patient's DH. To the best of our knowledge, this is the first case report which has demonstrated the possible biochemical pathways, triggered by sulfasalazine, in the development of vitiligo.

Complement Activation in Autoimmune Bullous Dermatoses: A Comprehensive Review

Autoimmune bullous dermatoses (AIBD) are characterized by circulating autoantibodies that are either directed against epidermal antigens or deposited as immune complexes in the basement membrane zone (BMZ). The complement system (CS) can be activated by autoantibodies, thereby triggering activation of specific complement pathways. Local complement activation induces a pathogenic inflammatory response that eventually results in the formation of a sub- or intraepidermal blister. Deposition of complement components is routinely used as a diagnostic marker for AIBD. Knowledge from different animal models mimicking AIBD and deposition of complement components in human skin biopsies provides more insight into the role of complement in the pathogenesis of the different AIBD. This review outlines the role of the CS in several AIBD including bullous pemphigoid, epidermolysis bullosa acquisita, mucous membrane pemphigoid (MMP), pemphigus, linear IgA-disease, and dermatitis herpetiformis. We also discuss potential therapeutic approaches targeting key complement components, pathways and pathogenic complement-mediated events.

Coagulation and Skin Autoimmunity

Several lines of evidence indicate that the immune system, inflammation, and coagulation are simultaneously activated in autoimmune and immune-mediated skin diseases. Pro-inflammatory cytokines such as interleukin-6 and tumor necrosis factor-alpha induce the expression of the main initiator of coagulation, i.e., tissue factor. The proteases of coagulation in turn act on protease-activated receptors inducing the expression of various pro-inflammatory cytokines triggering inflammation. The cross-talk among immune system, inflammation, and coagulation amplifies and maintains the activation of all three pathways. This review focuses on three skin disorders as chronic spontaneous urticaria (CSU), angioedema, and bullous pemphigoid (BP), in which the relationships among the three systems have been investigated or their clinical consequences are relevant. Markers of thrombin generation, fibrinolysis, and inflammation have been reported to be increased in the plasma during flares of CSU and angioedema, as well as in the active phase of BP, with the marker levels reverting to normal during remission. The coagulation activation seems to be important only at local level in CSU and angioedema while both at local and systemic levels in BP which is the only condition associated with an increased thrombotic risk. The prothrombotic state in autoimmune skin diseases raises the question of the indication of anticoagulant treatment, particularly in the presence of other cardiovascular risk factors.