What Is an Autoimmune Disorder?

Autoimmune disorders are medical conditions where the immune system attacks your cells and tissues. Some affect particular organs or cell types while others affect the whole body. You might be familiar with some of them: multiple sclerosis, rheumatoid arthritis, lupus, Crohn’s disease, type 1 diabetes, psoriasis and celiac disease are among the most common. In this post, I’m focusing on two of these conditions: psoriasis and celiac disease.

What Is Psoriasis?

Psoriasis is an autoimmune disorder that causes the skin to grow or regenerate more quickly. Its most common presentation is called chronic plaque psoriasis: small or large thickened areas of red skin, often covered with silvery flaking scales. These areas are most often found on the elbows, knees and back, but they can also appear on other parts of the body.

The pain associated with the plaques can be an uncomfortable itch, ache or burning sensation. Chronic plaque psoriasis tends to go through cycles, flaring up and fading for a time, although psoriasis patches can also be very persistent.

If you have psoriasis or you know someone who has it, you’re probably very familiar with these physical manifestations. You might also be aware of the emotional distress it can cause. It is associated with low self-esteem and depression, which is at least partially due to social focus on image.

It’s also important to realize that people with psoriasis are known to have a greater risk of developing other autoimmune conditions, including celiac disease.

What Is Celiac Disease?

Celiac disease is a serious autoimmune condition that is believed to affect around 1% of the population, although it often goes undiagnosed for much of people’s lives. If someone has celiac disease and they eat anything containing certain proteins, their immune system attacks their own tissues, particularly the lining of the intestine. Damage to this tissue affects the ability to absorb nutrients from food.

The proteins that cause the autoimmune reaction are gliadins and glutenins, which are also referred to as gluten proteins. We associate them with wheat, but similar proteins are found in wheat subspecies like durum and spelt, and in other crops, including barley, rye and even oats.

Celiac disease has a wide range of gastrointestinal symptoms, but patients can also exhibit various systemic symptoms. The initial symptoms can appear weeks to years after the initial consumption of gluten proteins, but as the disease progresses, the reaction time becomes much shorter and can be far more intense. The treatment is diet free of any of the proteins that cause the reaction.

What Connects Psoriasis and Celiac Disease?

Evidence from multiple studies supports an association between psoriasis and celiac disease. One analysis of the literature showed that psoriasis patients are over two times more likely to be diagnosed with celiac disease; and celiac disease patients are almost two times more likely to have psoriasis.

Furthermore, psoriasis and celiac disease are both related to a particular immune cell type called T helper (Th) cells. Th1 and Th17 are involved in both conditions. Also, over 16% of patients with psoriasis have higher than average levels of antibodies associated with celiac disease, such as anti-gliadin IgA, anti-gliadin IgG and anti-tissue transglutaminase IgA.

What Is the Case Study about?

The case study “Development of Dermatitis Herpetiformis in Chronic Plaque Psoriasis” reports on a white, cisgender man with a 40-year history of chronic plaque psoriasis that was getting worse, and a 3-month history of another autoimmune skin condition, dermatitis herpetiformis. He did not have a diagnosis of celiac disease The patient’s serological screen for celiac disease showed higher than average levels of anti-gliadin IgA, anti-gliadin IgG and anti-tissue transglutaminase IgA. A subsequent endoscopy confirmed a diagnosis of celiac disease.

Part of the patient’s treatment involved a gluten-free diet, although surgical and pharmacological interventions were also needed due to the severity of the conditions. The gluten-free diet was confirmed to have a significant positive impact on both the dermatitis herpetiformis and psoriasis, although the patient had difficulty sustaining the diet in the long term.

What Does This Mean in Practice?

As the paper mentioned above is a case study, its conclusions cannot be considered thoroughly clinically tested, but the connection between psoriasis and celiac disease relies on evidence from several other studies.

Thus, since there is evidence of a significant association between the two autoimmune disorders, it is logical to consider serologically screening psoriasis patients for markers of celiac disease, especially if they present with gastrointestinal problems. If a patient with psoriasis tests positive, then a balanced gluten-free diet should at least be trialed. It might improve the patient’s skin condition and protect them from any autoimmune reactions to the gluten proteins.

Should I “Go Gluten-Free” If I Have Psoriasis?

As mentioned in Dr. George Marx’s post “How Useful Is a Gluten-Free Diet?”, a gluten-free diet is not harmful provided your nutrition is balanced. Unfortunately, it can be difficult to create a balanced gluten-free diet, so you should always seek support from a doctor or dietician before taking such a decision.