Dermatitis Herpetiformis Patients Research Articles

Differences in the detection of circulating Hsp90 alpha between patients with atopic dermatitis and dermatitis herpetiformis.

Heat shock protein 90 alpha (Hsp90α) is one of the key intra- and extracellular chaperones responsible for the biological activity of various signaling molecules that are involved in (auto)immune-mediated inflammatory diseases. Recent epidemiologic data suggest that patients with atopic dermatitis (AD) are at risk for several autoimmune diseases, including dermatitis herpetiformis (DH), an extraintestinal manifestation of celiac disease (CD). In addition, pruritic diseases such as AD may be confused clinically with DH. In this study, we aimed to determine the role of circulating Hsp90α in patients with AD in relation to patients with DH, CD, and healthy controls. Using an enzyme-linked immunosorbent assay, levels of circulating Hsp90α were determined in serum samples derived from patients with AD (n = 31), DH (n = 26), CD (n = 15), and healthy controls (n = 55). Although serum concentrations of Hsp90α were similar between patients with DH, CD, and healthy controls, we found that serum levels of Hsp90α were significantly higher (mean value of 5.08-fold; p < 0.0001) in patients with AD when compared to patients with DH. A cutoff value calculated as 2 × standard deviation above the mean concentration of Hsp90α in DH patients revealed that 83.9% (26/31) of AD patients were Hsp90α positive, whereas none of the DH patients (0/26) displayed such a positivity. This preliminary study suggests a distinct role for extracellular Hsp90α in the pathogenesis of AD compared to DH and its potential use in distinguishing AD from DH. Nevertheless, the potential role of the evaluation of extracellular Hsp90α for distinguishing between AD and DH is at present speculative and requires further and careful observations.

Autoantibody binding and unique enzyme-substrate intermediate conformation of human transglutaminase 3

Transglutaminase 3 (TG3), the autoantigen of dermatitis herpetiformis (DH), is a calcium dependent enzyme that targets glutamine residues in polypeptides for either transamidation or deamidation modifications. To become catalytically active TG3 requires proteolytic cleavage between the core domain and two C-terminal β-barrels (C1C2). Here, we report four X-ray crystal structures representing inactive and active conformations of human TG3 in complex with a TG3-specific Fab fragment of a DH patient derived antibody. We demonstrate that cleaved TG3, upon binding of a substrate-mimicking inhibitor, undergoes a large conformational change as a β-sheet in the catalytic core domain moves and C1C2 detaches. The unique enzyme-substrate conformation of TG3 without C1C2 is recognized by DH autoantibodies. The findings support a model where B-cell receptors of TG3-specific B cells bind and internalize TG3-gluten enzyme-substrate complexes thereby facilitating gluten-antigen presentation, T-cell help and autoantibody production.

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.

Risk of vascular diseases in patients with dermatitis herpetiformis and coeliac disease: a long-term cohort study

Introduction Dermatitis herpetiformis (DH) is a cutaneous manifestation of coeliac disease. Increased cardiovascular morbidity has been reported in coeliac disease, but in DH only little is known about this. In this cohort study with a long-term follow-up, the risk for vascular diseases in patients with dermatitis herpetiformis (DH) and coeliac disease was assessed. Methods The study consisted of 368 DH and 1072 coeliac disease patients with biopsy-proven diagnosis performed between 1966 and 2000. For each DH and coeliac disease patient three matched reference individuals were obtained from the population register. Data regarding all outpatient and inpatient treatment periods between 1970 and 2015 were reviewed for diagnostic codes of vascular diseases from the Care Register for Health Care. Cox proportional hazard model was used to assess the risks for the diseases studied and the HRs were adjusted for diabetes mellitus (aHR). Results The median follow-up time of DH and coeliac disease patients was 46 years. The risk for cardiovascular diseases did not differ between DH patients and their references (aHR 1.16, 95% CI 0.91–1.47), but among coeliac disease patients, the risk was increased (aHR 1.36, 95% CI 1.16–1.59). The risk for cerebrovascular diseases was found to be decreased in DH patients when compared with references (aHR 0.68, 95% CI 0.47–0.99) and increased in coeliac disease patients (aHR 1.33, 95% CI 1.07–1.66). The risk for venous thrombosis was increased in coeliac disease patients (aHR 1.62, 95% CI 1.22–2.16) but not in DH. Conclusions The risk for vascular complications appears to differ between DH and coeliac disease. In DH the risk for cerebrovascular diseases seems to be decreased, while in coeliac disease an elevated risk for cerebrovascular and cardiovascular diseases was observed. These differing vascular risk profiles between the two manifestations of the same disease merit further investigation.

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

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

184 HLA-DQB1 associations among Bulgarian patients with dermatitis herpetiformis

Dermatitis herpetiformis (DH) is a rare autoimmune bullous dermatosis. There are only few HLA studies among DH patients and data among the Bulgarian population are scarce. Research in the field has indicated DH association with HLA DQ2 (DQA1*05:01 & DQB1*02) and DQ8 (DQA1*03:01 & DQB1*03:02) in Caucasians. The aim of our study was to evaluate the HLA-DQB1 typing among Bulgarian DH patients. A total of 37 DH patients (24 men, 13 women) and 41 healthy controls (22 men, 19 women) were analyzed. DNA was extracted from blood samples using iPrep PureLink (Invitrogen).

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.

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.

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

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

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.

Risk of fractures in dermatitis herpetiformis and coeliac disease: a register-based study

Objectives: Dermatitis herpetiformis (DH) is a cutaneous manifestation of coeliac disease. Bone fracture risk is increased in coeliac disease, but little knowledge exists about bone complications in DH. This study aimed to evaluate the risk of hip and other hospital-treated fractures in DH and coeliac disease in a high prevalence area with good adherence to a gluten-free diet.Materials and methods: Hip, proximal humerus, wrist and ankle fractures in 368 treated DH and 1076 coeliac disease patients between 1970 and 2015 were reviewed from the National Hospital Discharge Register. Hip fracture incidence rates for DH and coeliac disease patients were compared to those for the general population. The overall fracture risk for DH was compared to coeliac disease.Results: The hip fracture incidence rates for DH and coeliac disease patients did not differ from the general population. In females aged 80–89, the hip fracture incidence was higher in DH than in coeliac disease, but the risk for any hospital-treated fracture was lower in DH compared to coeliac disease (adjusted HR 0.620, 95% CI 0.429–0.949). The DH and coeliac disease patients with hospital-treated fractures were diagnosed at an older age, but the degree of small bowel mucosal damage did not significantly differ between patients with and without fractures.Conclusion: The incidence of hip fracture is not increased in treated DH or coeliac disease in an area with high awareness and dietary compliance rates. However, patients with DH seem to have a lower risk for fractures overall compared to coeliac disease.

Dermatitis Herpetiformis: Novel Perspectives.

Dermatitis herpetiformis (DH) is an inflammatory disease of the skin, considered the specific cutaneous manifestation of celiac disease (CD). Both DH and CD occur in gluten-sensitive individuals, share the same Human Leukocyte Antigen (HLA) haplotypes (DQ2 and DQ8), and improve following the administration of a gluten-free diet. Moreover, almost all DH patients show typical CD alterations at the small bowel biopsy, ranging from villous atrophy to augmented presence of intraepithelial lymphocytes, as well as the generation of circulating autoantibodies against tissue transglutaminase (tTG). Clinically, DH presents with polymorphic lesions, including papules, vesicles, and small blisters, symmetrically distributed in typical anatomical sites including the extensor aspects of the limbs, the elbows, the sacral regions, and the buttocks. Intense pruritus is almost the rule. However, many atypical presentations of DH have also been reported. Moreover, recent evidence suggested that DH is changing. Firstly, some studies reported a reduced incidence of DH, probably due to early recognition of CD, so that there is not enough time for DH to develop. Moreover, data from Japanese literature highlighted the absence of intestinal involvement as well as of the typical serological markers of CD (i.e., anti-tTG antibodies) in Japanese patients with DH. Similar cases may also occur in Caucasian patients, complicating DH diagnosis. The latter relies on the combination of clinical, histopathologic, and immunopathologic findings. Detecting granular IgA deposits at the dermal-epidermal junction by direct immunofluorescence (DIF) from perilesional skin represents the most specific diagnostic tool. Further, assessing serum titers of autoantibodies against epidermal transglutaminase (eTG), the supposed autoantigen of DH, may also serve as a clue for the diagnosis. However, a study from our group has recently demonstrated that granular IgA deposits may also occur in celiac patients with non-DH inflammatory skin diseases, raising questions about the effective role of eTG IgA autoantibodies in DH and suggesting the need of revising diagnostic criteria, conceivably emphasizing clinical aspects of the disease along with DIF. DH usually responds to the gluten-free diet. Topical clobetasol ointment or dapsone may be also applied to favor rapid disease control. Our review will focus on novel pathogenic insights, controversies, and management aspects of DH.

DNA damage in human skin fibroblasts from patients with dermatitis herpetiformis.

Dermatitis herpetiformis (DH) and celiac disease (CD) are considered to be autoimmune diseases that share a specific trigger (gluten) and a common genetic background (HLA-DQ2/DQ8). However, the pathogenesis of DH is not yet fully understood and no data are available regarding a possible role of fibroblasts in this disease. The aim of this study was to assess baseline DNA damage in fibroblasts in DH-diagnosed patients vs. fibroblasts of controls without DH or CD. Primary fibroblast cultures were derived from dermal biopsies from DH patients and controls (without DH or CD). In vitro genotoxic damage was investigated using the comet assay and ɣH2AX test after different treatments (with 33mer peptide and digested gliadin [DG]) in order to investigate a correlation between oxidative stress (evaluated by reactive oxygen species formation) and glutathione content. Our results demonstrate a difference in baseline DNA damage between cutaneous fibroblasts of controls and DH patients, moreover, DNA damage significantly increased after exposure to gluten (DG and 33mer peptide) in fibroblasts from DH patients. DNA damage in fibroblasts from patients under dapsone treatment was similar to that of the control group. Our data indicate that oxidative stress and DNA damage may be characteristics of fibroblasts from DH patients who are not treated with dapsone, particularly after exposure to gliadin peptides.

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

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

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.

Prognosis of Dermatitis Herpetiformis Patients with and without Villous Atrophy at Diagnosis.

Dermatitis herpetiformis (DH) is a cutaneous manifestation of coeliac disease. At diagnosis, the majority of patients have villous atrophy in the small bowel mucosa. The objective of this study was to investigate whether the presence or absence of villous atrophy at diagnosis affects the long-term prognosis of DH. Data were gathered from the patient records of 352 DH and 248 coeliac disease patients, and follow-up data via questionnaires from 181 DH and 128 coeliac disease patients on a gluten-free diet (GFD). Of the DH patients, 72% had villous atrophy when DH was diagnosed, and these patients were significantly younger at diagnosis compared to those with normal small bowel mucosa (37 vs. 54 years, p < 0.001). Clinical recovery on a GFD did not differ significantly between the DH groups, nor did current adherence to a GFD, the presence of long-term illnesses, coeliac disease-related complications or gastrointestinal symptoms, or quality of life. By contrast, the coeliac disease controls had more often osteopenia/osteoporosis, thyroid diseases, malignancies and current gastrointestinal symptoms compared to the DH patients. In conclusion, villous atrophy at the time of DH diagnosis does not have an impact on the clinical recovery or long-term general health of DH patients.

Dermatitis Herpetiformis: A Common Extraintestinal Manifestation of Coeliac Disease.

Dermatitis herpetiformis (DH) is a common extraintestinal manifestation of coeliac disease presenting with itchy papules and vesicles on the elbows, knees, and buttocks. Overt gastrointestinal symptoms are rare. Diagnosis of DH is easily confirmed by immunofluorescence biopsy showing pathognomonic granular immunoglobulin A (IgA) deposits in the papillary dermis. A valid hypothesis for the immunopathogenesis of DH is that it starts from latent or manifest coeliac disease in the gut and evolves into an immune complex deposition of high avidity IgA epidermal transglutaminase (TG3) antibodies, together with the TG3 enzyme, in the papillary dermis. The mean age at DH diagnosis has increased significantly in recent decades and presently is 40–50 years. The DH to coeliac disease prevalence ratio is 1:8 in Finland and the United Kingdom (U.K.). The annual DH incidence rate, currently 2.7 per 100,000 in Finland and 0.8 per 100,000 in the U.K., is decreasing, whereas the reverse is true for coeliac disease. The long-term prognosis of DH patients on a gluten-free diet is excellent, with the mortality rate being even lower than for the general population.