Gluten represents a group of proteins that are found in wheat, barley, and rye. Gluten is not present in rice and oats. Celiac disease, also know as “gluten-sensitive enteropathy,” is a type of hypersensitivity or allergy to the gluten proteins that causes inflammation and damage to membranes lining the small intestine. This may result in gastrointestinal symptoms such as abdominal cramps and diarrhea as well as poor absorption of important nutrients, iron, and vitamins.
Celiac disease can be diagnosed with either a biopsy of the small intestine or the newer blood tests in the “celiac panel” which consists of an enzyme level and measurements of the antibodies against gluten. Naturally, the blood test is much easier to do for the patient. It has been determined from this test that 1% of persons in the U.S. have celiac disease which makes it fairly common.
Elsewhere on this site, I discussed the autoimmune skin disease called Dermatitis Herpetiformis (DH). I have always considered DH to be a rare disease, yet all patients with DH have evidence of gluten allergy based on blood tests and celiac disease if their intestines are examined. Most patients with DH do not complain of gastrointestinal symptoms. However, all patients with DH and celiac disease will respond completely if they are are able to follow a strict gluten-free diet. Not all patients with celiac disease have DH, but a recent study by investigators in Finland indicated that one out of six persons with celiac disease also had Dermatitis Herpetiformis.
The food processing and food service industries have become responsive to the needs of the gluten-sensitive people. It is now much easier to obtain gluten-free foods in the supermarket for home preparation or eat at a restaurant and order from the gluten-free menu. There has also been a surge of interest in the effect of gluten-free diets on people who have common skin diseases such as psoriasis or atopic dermatitis or eczema, but not DH.
Both psoriasis and atopic dermatitis are considered inflammatory diseases with an abnormal immune system component. Their skins are red and itchy, and they may be hypersensitive to many antigens, foods, and substances in the environment. Indeed, some of them must have celiac disease by chance. A gluten-free diet would likely help to reduce overall inflammation of the skin disease along with improvement of malabsorption of nutrients from the gut. My rough approximation based on the prevalence of all the diseases involved is that about 2-4/10,000 people would have psoriasis or eczema along with celiac disease.
Because of the rarity of the association, I don’t routinely order a celiac panel for patients with psoriasis or eczema. So far, whenever I have, the results have ruled out celiac disease. Notwithstanding, I do have patients with psoriasis who have started taking a gluten-free diet of their own free will and whose skin has most certainly improved. I think the explanation for this is the weight loss which routinely results from the diet. Foods containing wheat, barley, and rye are usually rich in carbohydrates and caloric content–think breads, pasta, pizza, beer, liquor. It has been shown that the severity of psoriasis is directly correlated with body mass index, thus weight loss by any means may improve psoriasis. For this reason, I encourage the gluten-free diet for those who are interested and inclined to follow it.