Dermatitis herpetiformis isn't the only skin condition closely linked with celiac disease – several studies show that psoriasis also shares a strong link with celiac disease and gluten found in the grains wheat, barley and rye.
One study blamed gluten in beer for psoriasis in some women, and other research also reports a link between celiac disease and psoriasis.
Specifically, the research indicates that psoriasis patients have high levels of gluten antibodies circulating in their bodies. These antibodies indicate that the psoriasis patients are reacting to the gluten in their diets, even though they haven't been diagnosed with celiac disease.
This doesn't necessarily mean gluten caused the psoriasis – research has yet to confirm that link. It could mean that psoriasis patients simply have higher rates of celiac disease, but that gluten doesn't play a role in their psoriasis. More research will need to be done to determine what, exactly, the connection between celiac disease and psoriasis means.
Both celiac disease and psoriasis are autoimmune conditions, meaning that in each case, your immune system mistakenly attacks part of your own body. In celiac disease, your immune system attacks your intestinal villi, while in psoriasis, it attacks your skin.
In psoriasis, thick, scaly red plaques develop on your skin as the skin's outer layer develops too rapidly. While psoriasis can appear at any age and sometimes even can be detected on babies in the womb, most people get the disease either early in their adult years.
About one-third of patients with psoriasis also suffer from joint stiffness, and up to 10% have psoriatic arthritis, a type of inflammatory arthritis. Up to 4.3% of psoriasis patients also have a diagnosis of celiac disease.
As of this point, no medical group has developed recommendations for celiac disease antibody testing in psoriasis patients.Celiac Disease Antibodies Found in Psoriasis Patients
At least two studies report finding gluten antibodies in patients with psoriasis, potentially indicating unrecognized celiac disease in those people.
For example, one report found significantly higher levels of celiac disease antibodies in patients with psoriasis than in matched control patients, and raised the possibility that some of these patients actually have latent celiac disease, which means you have positive blood tests but a normal intestinal biopsy.
Another study took blood samples from patients with particularly bad psoriatic lesions, along with samples from healthy people with no family history of psoriasis or celiac disease. The researchers found that the patients with psoriasis had significantly higher concentrations of two types of antibodies used to diagnose celiac disease.
However, none of the patients in that study had IgA anti-endomysial antibodies, which physicians consider the most sensitive and specific to a celiac disease diagnosis. Still, the researchers concluded that "our results seem to imply an association between psoriasis and asymptomatic celiac disease/gluten intolerance."
Can A Gluten-Free Diet Help Psoriasis Sufferers?If you've been diagnosed with both psoriasis and celiac disease, you'll need to follow the gluten-free diet to treat your celiac disease. As a bonus, it might help your psoriasis. But should psoriasis patients who haven't been diagnosed with celiac disease consider the gluten-free diet, too?
Several anecdotal reports indicate that some psoriasis patients see their skin improve dramatically on a gluten-free diet. In fact, the researchers from one of the studies noted that "psoriasis can coexist with clinically asymptomatic celiac disease and a gluten-free diet helps to obtain remission, even in patients with very chronic lesions."
If you're interested in giving it a try, it's wise to discuss this with your doctor first.
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P. Gisondi et al. Psoriasis, the liver, and the gastrointestinal tract. Dermatologic Therapy. 2010 mar;23(2):155-159.
A. Qureshi et al. Alcohol intake and risk of incident psoriasis in U.S. women: A prospective study. Archives of Dermatology. Published online August 16, 2010. http://archderm.ama-assn.org/cgi/content/full/archdermatol.2010.204.
S. Singh et al. Celiac disease-associated antibodies in patients with psoriasis and correlation with HLA Cw6. Journal of Clinical Laboratory Analysis. 2010;24(4):269-72.