Association between psoriasis and coeliac disease

Could it be gluten? Additional skin conditions associated with celiac disease

Celiac disease is a multifactorial, inflammatory disorder initiated and sustained by the ingestion of gluten. Occurring across a broad population, the intestinal and extraintestinal manifestations of celiac disease are variable in severity and may be nonspecific in presentation. Given that environmental, genetic, and immune factors involved in the pathogenesis of celiac disease that the digestive tract and skin share many characteristics, and with a prevalence of 0.5-1% in most populations, it is reasonable to consider varying presentations of skin conditions that are linked with celiac disease. The association between celiac disease and skin conditions has been discussed earlier, but new studies have emerged suggesting cutaneous involvement in addition to dermatitis herpetiformis. We review the current literature identifying the relationship and potential mechanisms between celiac disease and various skin conditions.

Digestive system in psoriasis: an update

Psoriasis is a chronic inflammatory immune-mediated disorder associated and often coexisting with many other immune-related clinical conditions including those affecting the gastrointestinal tract. Data obtained from the reviewed literature suggest an association between psoriasis and pathologies of the oral cavity, both psoriasis-specific lesions, as well as non-specific, such as geographic tongue or fissured tongue. These findings show the importance of thorough examination of oral mucosa in psoriatic patients. Inflammatory bowel diseases (IBD) are also linked with psoriasis. Crohn’s disease and ulcerative colitis share a common genetic background, inflammatory pathways and have an evident iatrogenic anti-TNF treatment link, necessitating dermatological or gastroenterological care in patients with IBD or psoriasis, respectively, as well as treatment adjusted to manifestations. The presence of celiac disease-specific antibodies in psoriatic patients and their correlation with the severity of the disease show the association between these disorders. The linking pathogenesis comprises vitamin D deficiency, immune pathway, genetic background and increase in the intestinal permeability, which suggests a potential benefit from gluten-free diet among psoriatic patients. The link between psoriasis and non-alcoholic fatty liver disease implies screening patients for components of metabolic syndrome and lifestyle changes necessity. Some studies indicate increased prevalence of cancer in patients with psoriasis, probably due to negative influence of skin lesion impact on lifestyle rather than the role of psoriasis in carcinogenesis. However, there are no sufficient data to exclude such an oncogenic hit, which is yet to be confirmed. Therefore, all psoriasis-associated comorbidities establish the importance of a multidisciplinary approach in the treatment of these patients.

Coeliac disease-associated antibodies in psoriasis

Background

The possible relationship between psoriasis and coeliac disease (CD) has been attributed to the common pathogenic mechanisms of the two diseases and the presence of antigliadin antibodies in patients has been reported to increase the incidence of CD.

Objective

The aim of this report was to study CD-associated antibodies serum antigliadin antibody immunoglobulin (Ig)A, IgG, anti-endomysial antibody IgA and anti-transglutaminase antibody IgA and to demonstrate whether there is an increase in the frequency of those markers of CD in patients with psoriasis.

Methods

Serum antigliadin antibody IgG and IgA, antiendomysial antibody IgA and anti-transglutaminase antibody IgA were studied in 37 (19 males) patients with psoriasis and 50 (23 males) healthy controls. Upper gastrointestinal endoscopy and duodenal biopsies were performed in patients with at least one positive marker.

Results

Antigliadin IgA was statistically higher in the psoriasis group than in the controls (p<0.05). Serological markers were found positive in 6 patients with psoriasis and 1 person from the control group. Upper gastrointestinal endoscopy was performed in all these persons, with biopsies collected from the duodenum. The diagnosis of CD was reported in only one patient with psoriasis following the pathological examination of the biopsies. Whereas one person of the control group was found to be positive for antigliadin antibody IgA, pathological examination of the duodenal biopsies obtain from this patient were found to be normal.

Conclusion

Antigliadin IgA prominently increases in patients diagnosed with psoriasis. Patients with psoriasis should be investigated for latent CD and should be followed up.

Psoriasis, the liver, and the gastrointestinal tract

Psoriasis is a common chronic inflammatory, immune-mediated skin disease that is frequently associated with comorbidities including psoriatic arthropathy, chronic inflammatory bowel diseases, and cardio-metabolic disorders. In particular, nonalcoholic fatty liver disease affects about half of patients, Crohn's disease 0.5% and celiac disease 0.2-4.3% of patients with psoriasis. Some shared genetic traits as well as common inflammatory pathways may underlie these associations. The presence of comorbidities has important implications in the global approach to patients. In particular, traditional systemic antipsoriatic agents could negatively affect cardio-metabolic comorbidities as well as nonalcoholic fatty liver disease and may have important interactions with drugs commonly used by psoriasis patients. Moreover, patients with psoriasis should be encouraged to drastically correct their modifiable cardiovascular and liver risk factors, in particular obesity, alcohol consumption, and smoking habit, because this could positively affect both psoriasis and their life expectance.

Prevalence of antigliadin antibodies in patients with psoriasis is not elevated compared with controls

BACKGROUND

Antigliadin antibodies (AGAs) are markers of celiac sprue but may have autoimmune implications in the absence of gastrointestinal disease. There is anecdotal evidence to suggest that gluten sensitivity may play a role in psoriasis, and patients with psoriasis in Europe have been reported to improve on a gluten-free diet.

OBJECTIVE

To assess whether patients with psoriasis in the US have an increased prevalence of elevated AGAs.

METHOD

A US sample of patients with psoriasis (n=100), patients with psoriasis and psoriatic arthritis (n=100), and age-matched control individuals without any personal or family history of autoimmune disorders (n=100) were tested for IgG and IgA AGAs.

RESULTS

No difference in the prevalence of abnormal AGAs among patients with psoriasis (14%), combined psoriasis and psoriatic arthritis (18%), and control individuals (19%) was observed. No significant correlations between AGA positivity and psoriasis severity, joint involvement, or age of onset of psoriasis or arthritis were observed.

CONCLUSION

We found no support for the results of prior studies showing that elevated AGAs occur with increased frequency in patients with psoriasis. Furthermore, the relatively high prevalence of abnormal AGAs in our control population suggests these antibodies may not be associated with autoimmune disease.

Cutaneous manifestations in celiac disease

Celiac disease (CD) is an autoimmune gluten-dependent enteropathy characterized by atrophy of intestinal villi that improves after gluten-free diet (GFD). CD is often associated with extra-intestinal manifestations; among them, several skin diseases are described in CD patients. The present review reports all CD-associated skin manifestations described in the literature and tries to analyze the possible mechanisms involved in this association. The opportunity to evaluate the possible presence of CD in patients affected by skin disorders is discussed.