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By Jessica Migala
June 07, 2021
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Most people think celiac disease affects the gut; after all, gluten can damage the small intestine. But gut-related changes aren't the only symptoms of celiac disease-there's a wide range of symptoms that can affect virtually every part of the body.

Because of all these varied symptoms, celiac disease can be hard to identify, and many people with it go undiagnosed. One symptoms that can make diagnosis especially tricky? Celiac disease rash, aka dermatitis herpetiformis (DH): an itchy, blistering skin rash.

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Credit: AdobeStock

What is celiac disease rash?

DH is the skin form of celiac disease, affecting 15% to 25% of patients with celiac disease, according to the patient advocacy and research organization Beyond Celiac. The rash most often develops in adults ages 30 to 40, with men and people of northern European descent most at risk, per the National Organization for Rare Disorders.

The rash is the result of a localized immune response, and it appears symmetrically on both sides of the body in high-flex places, like the elbows, knees, and butt, as well as the face, scalp, back, and groin, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) notes. The rash develops from consuming gluten, not touching gluten.

In more than 80% of patients with DH, the rash is the only symptom of celiac disease. "Most people do not think this is celiac. Instead of gluten triggering an inflammatory response in the gut, it triggers this response in the skin," Salvatore Alesci, MD, PhD, chief scientist and strategy officer at Beyond Celiac, tells Health. "If you have the dermatitis herpetiformis rash, you have celiac disease. Period. You do not need to have any gastrointestinal symptoms."

What does celiac disease rash feel and look like?

The itch is one of the worst and most significant parts of celiac disease rash. "Patients complain that they're so itchy, they want to take their skin off," Dr. Alesci says. But just like diagnosing celiac disease itself can be hard, identifying celiac disease rash can be tough, too. That's because the blistering lesions look similar to herpes, which can lead to a misdiagnosis. (As Dr. Alesci points out, one of the root words of dermatitis herpetiformis is "herpes" because of how much the two conditions look alike.)

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Credit: DermNet NZ

Due to the intensity of the itch, it's common for patients to scratch so hard they remove these lesions with their nails, making the rash look different, according to the NIDDK. "Because dermatitis herpetiformis is so itchy, it can frequently be misdiagnosed as eczema, especially if someone comes in after they popped and scratched off the blisters," Amy Burkhart, MD, an integrative medicine physician and registered dietitian who specializes in gut health, tells Health. If your provider has told you that you have eczema or a rash and typical treatment for those conditions isn't working, then ask for a referral to a dermatologist, she advises.

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Credit: DermNet NZ
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Credit: DermNet NZ

A fifth of patients with DH will also have dental symptoms, the NIDDK reports. You might see enamel problems (such as teeth discoloration) or oral lesions (canker sores), Dr. Alesci says. If you have both a rash and teeth discoloration or frequent cavities, it's a good time to ask your dermatologist if your rash could be a manifestation of celiac disease.

How is celiac disease rash diagnosed?

If DH is suspected, your dermatologist will need to take a skin biopsy next to the lesion to get an accurate test result. If you have DH, they will find IgA antibody deposits from the biopsy, and that will confirm the diagnosis, according to the NIDDK. (IgA antibodies are one of the most common antibodies in the body, but they are often found at high levels in people with autoimmune conditions like celiac disease.) At that point, while an intestinal biopsy probably won't be needed, some providers might still recommend one, Dr. Alesci says.

How is celiac disease rash treated?

Unfortunately, DH is stubborn. "Patients need to be on a strict gluten-free diet for two years," Dr. Alesci says. It can take that long for the rash to begin to clear.

Going gluten-free eases symptoms a lot quicker for people who have celiac disease without DH. "When patients take gluten out of their diet, they feel better within days to weeks," Dr. Burkhart explains. But with DH, the duration of the rash-even with treatment-is brutal because of the itchiness.

That's why a gluten-free diet isn't the only treatment for DH. You'll also need relief from the itchiness and burning of the rash in the meantime.

Dermatologists are experts in the skin and are best for helping diagnose and treat DH. If you're diagnosed, your provider will prescribe dapsone, an oral antibiotic and anti-inflammatory that will help relieve the symptoms of the rash. Sometimes, dapsone may need to be taken for one or two years, according to Dr. Alesci.

If dapsone doesn't help much, then patients might also use a topical hydrocortisone or lidocaine cream for relief, Dr. Burkhart says. Dapsone can also cause side effects, including hemolytic anemia, which is when red blood cells are destroyed faster than they can be made. In these cases, alternative medications including sulfapyridine (an antibiotic) or sulfasalazine (a disease-modifying anti-rheumatic drug used to treat autoimmune conditions) may be prescribed.

One thing you want to avoid is taking an oatmeal bath, which is a commonly recommended skin-soothing treatment. Even if this rash isn't triggered by touching gluten, it's best to stay away from oatmeal soaks, according to Dr. Burkhart. "People who have celiac can react to oatmeal," she says. You'll also want to practice gentle skincare-such as taking short, cool showers-to promote skin barrier repair and function.

Can celiac disease rash be prevented?

The goal is to eventually stop medication once the rash has disappeared. But even after it has, you'll still need to stay gluten-free. This won't just help clear up the rash long-term, it will also prevent gluten from damaging the small intestines.

But while a gluten-free diet will decrease the risk of DH coming back, it's not a guarantee. Relapses of DH are common, according to Dr. Alesci. However, in some cases, even without treatment, DH can disappear seemingly at random, though no one knows why.

For some people, a diet high in iodine may trigger future flares of DH, Dr. Burkhart notes. If that's the case, your doctor or a registered dietitian can help give you advice about avoiding iodine-rich foods, such as seaweed, cod, shrimp, yogurt, milk, and iodized salt.

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