When Renee Brown began breaking out in small, itchy blisters on the tops of her hands and on her scalp, she didn’t know what to make of it. Neither did the physicians she saw in pursuit of a diagnosis.

“The doctors had no clue what was going on,” said the 59-year-old retired college counselor, who lives near Corpus Christi, Texas. “I went to several for four years trying to figure out what was happening. I was never a sick person before but I was told I had a rare form of rheumatoid arthritis, lupus, fibromyalgia, bad circulation, stress and allergies.”

The condition got so bad that it caused discoloration. “My blisters on my hands had purplish scars. I would wear makeup on my hands,” Brown says.

It wasn’t until she was washing dishes at her daughter-in-law’s house that Brown finally got some clarity.

“She saw my purple scars and said, ‘Hey, you know those purple scars look like my friend’s and she has celiac disease,’” Brown recalls. “I looked up coeliac disease and I had many of the symptoms. I printed out everything and went to a new doctor who is more into healthy eating and exercise. We talked and he said, ‘Get off gluten.’ But he gave me very little guidance, so I started reading books and labels.”

Brown eventually took a blood test for coeliac but tested negative because she had already been gluten-free for a year.* However, an endoscopy confirmed she had coeliac disease.

For many people with coeliac disease, gastrointestinal symptoms such as abdominal pain and diarrhea take center stage. But for a subset of people with coeliac disease, eating or coming into contact with gluten results in a vicious skin rash, either as the only symptom or as a complement to the more typical ones. This rash, known as dermatitis herpetiformis, or DH, typically presents as a series of small raised red lesions that are either solid or filled with fluid. They often show up on the elbows, forearms, scalp, knees, buttocks and even the face. They’re usually bilaterally symmetrical, meaning they appear on both sides of the body at the same time, and they are intensely itchy.

DH isn’t all that common. “We find that 5 to 10 percent of our coeliac disease patients have DH—and that’s likely an overestimate compared to the general coeliac population, since people with more challenging situations, including DH, are more likely to come to our center,” said Benjamin Lebwohl, MD, MS, director of clinical research at Columbia University’s Coeliac Disease Center in New York. “As for why certain people with coeliac disease develop DH while most do not, this is unknown.”

Unlike coeliac disease, the incidence of DH in recent years appears to be decreasing—again for unknown reasons, Lebwohl says.

Why would the incidence of DH be declining? It’s possible that as coeliac disease is being diagnosed more frequently and treated with a gluten-free diet, potential cases of dermatitis herpetiformis are being avoided.

John Zone, MD, a Salt Lake City dermatologist with expertise in blistering diseases of the skin, says that only about one third to one half of people with dermatitis herpetiformis have any gastrointestinal symptoms of celiac disease. However, if those who do have GI symptoms address them and get an accurate diagnosis, it’s conceivable that some are preventing the development of DH by sticking to a strict gluten-free diet. Zone explains that people who have DH have developed antibodies not just to tissue transglutaminase, or TTG, but to epidermal transglutaminase, or TTG3.

“Their immune response to this entire situation expands to TTG3” if they continue to stimulate their immune system by eating gluten, Zone says.

He says that DH tends to be a later manifestation of coeliac disease, not its first marker. This makes sense if DH is viewed as a progression of the disease. According to Zone, the average age of DH onset is 38, significantly later than the average age of coeliac disease diagnosis.

Because DH can be confused with other skin conditions, such as eczema, experts say that blood work to detect coeliac antibodies and a skin biopsy using samples taken from skin directly adjacent to the rash are key to making an accurate diagnosis. In someone with DH, a fluorescent dye applied to the skin sample will reveal deposits of immunoglobulin A (IgA) in a granular pattern.

“False positive biopsies are uncommon but false negative biopsies can occur if the proper location is not sampled or if the specific kind of microscopic examination is not done (direct immunofluorescence),” says Lebwohl. While most people with DH will have heightened levels of coeliac disease antibodies in their blood and will display damage if their intestines are biopsied, a minority of DH patients will have normal blood work and intestinal biopsy results, he says. This can complicate the quest for an accurate diagnosis.

People with DH may also have a heightened risk of thyroid disorders. A 1990 study of 56 patients with DH and 26 control subjects found that 32 percent of subjects with the condition were found to have abnormal thyroid function compared with just 4 percent of the controls.

They may be especially sensitive to iodine exposure as well, according to Lebwohl. “Some patients with DH experience flares of their symptoms when exposed to high concentrations of dietary iodine, such as shellfish,” he says. “But this is not always the case and strict iodine avoidance is not generally advised.”

Managing Dermatitis Herpetiformis

When itchy spots began to erupt on Jay Grayson’s neck, knees, elbows and buttocks years ago, he figured his sports equipment was causing the breakouts. After spending a year on prescription steroid creams and lotions that didn’t help, his dermatologist did a skin biopsy that confirmed DH.

“My dermatologist told me at that time I needed to go on a gluten-free diet and he prescribed dapsone for my DH,” says the 41-year-old pharmaceutical sales professional from Birmingham, Alabama, who admitted that he didn’t follow the advice. “At that time, DH was my only symptom of celiac disease, so I continued to eat what I wanted and take dapsone for my DH.” Dapsone, an antibiotic, is a mainstay of DH treatment, along with antihistamine medications for certain patients.

However, Grayson says “very serious” gastrointestinal issues landed him in the hospital about five years ago, where an intestinal biopsy confirmed the diagnosis of celiac disease. The unpleasantness of this experience convinced him that he needed to take control of his diet and be strict about avoiding gluten, which he has done ever since. Still, occasional cross-contamination occurs—with predictable results.

“I definitely know when I’ve eaten something that has been contaminated with gluten,” he says. “My DH will come out with the littlest bit of gluten. I always have dapsone on hand for those occasions. It’s not often, as I haven’t taken dapsone in over a year, but when my DH flares, it is miserably itchy.”

As with all drugs, dapsone has side effects, says Zone. These include anemia, lowered white blood cell count and even nerve issues if taken over the long term. But while Grayson and many other patients depend on dapsone for relief, not everyone embraces the idea of medication.

Elizabeth Gavino has DH. She struggled for years with many illnesses, including depression, menstrual irregularities and gastrointestinal problems that landed her in the hospital, before finding out that she had celiac disease with DH. Choosing to steer clear of drugs, she focuses instead on being scrupulously careful about her gluten-free diet as a way to control her condition.

“If I eat gluten, I’ll know because I’ll have DH for two weeks,” says the 45-year-old from Hoboken, New Jersey.

This is not uncommon; experts say that the rash can linger for weeks and even months after stopping gluten exposure. Gavino has not had a flare-up for the past six years, except for a brief period when she first dated a man who used a particular facial product that contained wheat. (He was willing to give it up in order to be close to her.)

For Gavino, the benefits of eating right go beyond the avoidance of inflamed and itchy skin.

“Once I got off gluten, I was more even in my emotions and I didn’t have the depression anymore,” she says, noting that she also avoids dairy and high fructose corn sweetener. Her rejuvenated health inspired her to leave a career in insurance and focus on bringing wellness to others in need of dietary guidance as a nutrition therapy practitioner.

“I choose to save my small intestine and to avoid developing other worse diseases,” she says. “People with DH and coeliac disease should ask themselves: Is that piece of gluten worth living a life of further disease and illness? Make peace with losing the gluten. The gluten-free product market has come a long way in making really wonderful substitutes. Understand your life will continue to be rich and tasty.”

Health and medical writer Laurie Saloman, MS, is the parent of a young adult with coeliac disease.