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.

Dermatitis herpetiformis: a cutaneous manifestation of coeliac disease.

Dermatitis herpetiformis (DH) is an itchy blistering skin disease with predilection sites on elbows, knees, and buttocks. Diagnosis is confirmed by showing granular immunoglobulin A deposits in perilesional skin. DH is one manifestation of coeliac disease; the skin symptoms heal with gluten free diet (GFD) and relapse on gluten challenge. Of the first-degree relatives, 5% may be affected by either condition. Tissue transglutaminase (TG2) is the autoantigen in coeliac disease and epidermal transglutaminase (TG3) in DH. Both diseases conditions exhibit TG2-specific autoantibodies in serum and small bowel mucosa; patients with DH have IgA-TG3 in the skin. There are some divergencies between these two phenotypes. One-fourth of DH patients do not have small bowel mucosal villous atrophy, but virtually all have coeliac-type inflammatory changes. The skin symptoms respond slowly to GFD. The incidence of coeliac disease is increasing, whereas the opposite is true for DH. A female predominance is evident in coeliac disease, while DH may be more common in males. Coeliac disease carries the risk of small intestinal T-cell lymphoma; in DH B-cell lymphomas at any site may prevail. Adult coeliac disease carries a slightly increased elevated mortality risk, whereas in DH, the relative mortality rate is significantly decreased. Key messages Dermatitis herpetiformis is a cutaneous manifestation of coeliac disease; both conditions are genetically determined and gluten-dependent. Gastrointestinal symptoms and the degree of villous atrophy are less obvious in dermatitis herpetiformis than in coeliac disease. Both show tissue transglutaminase (TG2) specific autoantibodies in serum and small bowel mucosa. In addition, TG3-targeted IgA antibodies are found in the skin of DH patients Both conditions carry an increased elevated risk of lymphoma, in coeliac disease small intestinal T-cell lymphoma, in dermatitis herpetiformis mainly B-cell lymphoma at various sites. Coeliac disease is currently eight times more common that DH; the incidence of DH is decreasing in contrast to that of coeliac disease, where it is increasing.

Dermatitis Herpetiformis Refractory to Gluten-free Dietary Treatment.

Dermatitis herpetiformis (DH) is a blistering skin disease, which is regarded as an extra-intestinal manifestation of coeliac disease. Refractory cases of coeliac disease, that do not respond to a gluten-free diet and which carry an increased risk of lymphoma, are well-known in coeliac disease. To determine whether refractory cases of DH with active rash and persistent small bowel atrophy occur we analysed our series of 403 patients with DH. Seven (1.7%) patients, who had been on a gluten-free diet for a mean of 16 years, but who still required dapsone to treat the symptoms of DH, were identified. Of these, one patient died from mucinous adenocarcinoma before re-examination. At re-examination skin immunoglobulin A (IgA) deposits were found in 5/6 refractory and 3/16 control DH patients with good dietary response. Small bowel mucosa was studied at re-examination from 5 refractory and 8 control DH patients and was normal in all 5 refractory and 7/8 control DH patients. One refractory DH patient died from adenocarcinoma, but no lymphoma developed in any of the patients. This study documents for the first time refractory DH, in which the rash is non-responsive to a gluten-free diet, but the small bowel mucosa heals. This differs from refractory coeliac disease, in which the small bowel mucosa does not heal on a gluten-free diet.

Dermatitis herpetiformis: pathognomonic transglutaminase IgA deposits in the skin and excellent prognosis on a gluten-free diet.

Dermatitis herpetiformis (DH) is an itchy, blistering skin disease with sites of predilection at the elbows, knees and buttocks. Although DH is mostly asymptomatic, all patients exhibit small bowel villous atrophy or at least coeliac-type inflammatory changes. Deposition of immunoglobulin A (IgA) in the papillary dermis is a key diagnostic feature of DH. Epidermal transglutaminase (TG3) is the antigen for IgA deposited in the skin, and tissue transglutaminase (TG2) is the antigen for IgA deposited in the small bowel mucosa. Clinically silent, but immunologically active coeliac disease in the gut appears to result in IgA TG3 antibody complexes aggregated into DH skin. The prevalence of DH in northern Europe is high (30-75/100,000), but its incidence is decreasing, possibly due to increased recognition of subclinical coeliac disease. The rash and small bowel heal on a gluten-free diet, which is a life-long treatment. The risk of non-Hodgkin's lymphoma is increased, but in patients with DH who adhere strictly to a gluten-free diet long-term prognosis is excellent.

Celiac disease evolving into dermatitis herpetiformis in patients adhering to normal or gluten-free diet.

OBJECTIVE: Dermatitis herpetiformis (DH) is a cutaneous form of celiac disease affecting ∼ 17% of celiac disease patients. The aim was to determine how often celiac disease precedes the development of DH, and what is the impact of gluten-free diet (GFD) in this phenotype change. MATERIAL AND METHODS: Our prospectively collected DH series from 1970 comprised 514 patients. We analyzed all DH patients who at least 2 years earlier had been diagnosed with celiac disease. DH diagnosis was confirmed by showing immunoglobulin A deposits in dermis. Serological and small bowel mucosal findings were analyzed, and the strictness of GFD treatment before and after the diagnosis of DH was evaluated. RESULTS: Twenty (4%) DH patients had a prior diagnosis of celiac disease. The median time interval between celiac disease and DH detection was 9.5 years. Before DH appeared 4 patients had been on a normal gluten-containing diet, 10 had dietary lapses on a GFD, and 6 were on a strict GFD. Celiac autoantibodies were positive in 7 out of 19 patients, and 5 out of 7 undergoing small bowel biopsy had partial villous atrophy. Following DH diagnosis the rash was controlled after a median of 6 months on a strict GFD. CONCLUSIONS: Patients with celiac disease may develop DH by time. This is most often an indicator of poor adherence to GFD, and a rigorous dietary intervention is necessary. In the majority of cases, DH will be detected without prior celiac disease diagnosis, but the physicians should recognize this phenotype alteration.

Chronic gastritis in dermatitis herpetiformis: a controlled study.

BACKGROUND AND OBJECTIVE: Previous small studies suggest that chronic atrophic gastritis is common in dermatitis herpetiformis (DH). We here examined the frequency and topography of chronic gastritis in 93 untreated DH subjects and in 186 controls with dyspepsia. METHODS: Specimens were drawn from the gastric corpus and antrum and examined for atrophy, intestinal metaplasia, and Helicobacter pylori. Duodenal biopsies were taken. RESULTS: Atrophic corpus gastritis was more frequent in DH than in controls (16.0% and 2.7%, resp., P < 0.001); atrophy in the antrum was rare in both groups (3.2% and 1.1%, P = 0.34). Intestinal metaplasia was present in 13 (14.0%) DH and 12 (6.5%) control patients (P = 0.038) and H. pylori in 17 (18.3%) and 17 (9.3%) (P = 0.028), respectively. Small-bowel villous atrophy was seen in 76% of the DH patients, equally in patients with and without chronic gastritis. One DH patient with atrophic gastritis developed gastric cancer. CONCLUSION: In DH, chronic atrophic gastritis was common in the corpus, but not in the antrum. H. pylori will partly explain this, but corpus atrophy is suggestive of an autoimmune etiology. Atrophic gastritis may increase the risk of gastric cancer. We advocate performing upper endoscopy with sufficient histologic samples in DH.