What Is Dermatitis Herpetiformis?
Dermatitis herpetiformis is a bumpy, very itchy skin rash that’s caused by gluten sensitivity. In fact, about 10%-25% of people with celiac disease get dermatitis herpetiformis. Celiac disease is an autoimmune disorder that keeps your body from digesting gluten, a protein found in wheat, rye, and barley. An autoimmune condition is when your immune system mistakes your own tissues for foreign invaders and attacks them.
It's possible to get dermatitis herpetiformis without celiac disease, but it's rare. This skin condition, also known as Duhring’s disease, causes blisters and a rash that looks like herpes, but it's not caused by the virus that causes herpes. So, it's not contagious. You only get it when your body is sensitive to gluten.
Doctors will be able to tell if your rash is caused by gluten by testing your blood and skin for antibodies (proteins made by your immune system to protect you from foreign invaders) to gluten.
Doctors don't yet know of any ways to prevent you from getting it, but you can reduce your chance of a flare-up if you eat a gluten-free diet.
Dermatitis Herpetiformis Causes and Risk Factors
The causes of dermatitis herpetiformis include:
Your genes. If you have certain gene types that make it hard for your body to tell your own tissues from foreign invaders, then you are more likely to get dermatitis herpetiformis. These gene types are called HLA-DQ2 and HLA-DQ8, and many people who have autoimmune conditions have these gene types. So, you’re more likely to get celiac disease, gluten-sensitive enteropathy (ongoing damage in your small intestine due to gluten), or dermatitis herpetiformis if one of your parents or a brother or sister has any of these conditions too.
Gluten in your food. When you have celiac disease or gluten-sensitive enteropathy (GSE) and eat foods with gluten, your intestines make an antibody called immunoglobulin A (IgA) in response. This protein flows into your bloodstream and builds up in the blood vessels under your skin, which triggers the dermatitis herpetiformis rash.
Although anyone can get dermatitis herpetiformis, you may be more likely to get it if you:
Are of northern European descent. Dermatitis herpetiformis is rare in people of African or Asian descent.
Have celiac disease or have a close relative who has dermatitis herpetiformis or celiac disease.
Have a history of autoimmune conditions in your family, especially the following:
Type 1 diabetes
Alopecia areata (a condition where you lose hair in patches, usually from your scalp)
Addison's disease (a condition where your adrenal glands don't make enough of the hormones aldosterone and cortisol)
Are assigned male at birth (AMAB). About twice as many people who are AMAB have dermatitis herpetiformis as people who are assigned female at birth (AFAB).
Are between 30 and 40 years old. It's rare in children and older people.
Dermatitis herpetiformis in childhood
Dermatitis herpetiformis rarely shows up before puberty. When it's diagnosed in kids, it's usually when they are 2-7 years old. Also, it seems to be more common in kids who are AFAB than kids who are AMAB.
The signs and symptoms of dermatitis herpetiformis are similar in adults and kids. However, in some cases, children also get rashes on their palms, face, and soles of their feet. Sometimes, they also have lumps deep under their skin.
Dermatitis Herpetiformis Symptoms
Your symptoms may include:
A skin rash with bumps and extremely itchy blisters (this is the most common symptom). The rash of dermatitis herpetiformis is usually a cluster of bumps on a patch of skin that has changed color from your usual skin tone. The bumps may be darker than your usual skin tone. If you have a light skin tone, they may look red or purple. You may also get blisters (fluid-filled bumps) that burn. The rash is so itchy that some people scratch their blisters off.
These rashes usually show up on your elbows, knees, butt, and scalp, although some people may also get rashes on their chest, stomach, and back. They usually show up on both sides of your body (for instance, both elbows or both butt cheeks) at the same time. When they heal, they don't usually leave a scar.
Changes in the way your teeth look. Some people may see pits, color changes, or grooves in their teeth. Also, some people get canker sores (small, painful sores on the inside of your cheeks or lips, under your tongue, or on your gums).
Digestive symptoms of celiac disease. These include stomach pain, bloating, cramping, and diarrhea or constipation.
Dermatitis Herpetiformis vs. Eczema
The rash of dermatitis herpetiformis can look like a few different skin conditions, such as:
Herpes, a common sexually transmitted disease (STD) that can cause blisters and ulcers around your mouth and on your genitals.
Scabies, a skin condition from little bugs that burrow into your skin. This causes small bumps that are very itchy, often in the folds of skin between your fingers and toes.
Hives, an itchy skin rash usually caused by an allergic reaction.
Eczema, a long-term condition where the outer skin layer is damaged, which makes it hard for your skin to keep its regular moisture level.
Eczema is very common, so it's the condition most often confused with dermatitis herpetiformis. Like dermatitis herpetiformis, eczema can lead to an intensely itchy rash and possibly bumps on your elbows and legs (especially behind your knees). But, unlike dermatitis herpetiformis, eczema also causes dry, flaky, and sometimes thickened patches of skin. Also, after your rash heals, the skin may be either lighter or darker than your usual skin tone for several months, especially if your natural skin tone is dark. Dermatitis herpetiformis usually heals without scars or other skin changes.
People with eczema can usually find relief from their itchy, dry skin with a good skincare routine, such as using soap-free cleansers and moisturizers. But these topical treatments won't help people with dermatitis herpetiformis.
Dermatitis Herpetiformis Diagnosis
Your doctor may suspect dermatitis herpetiformis from your symptoms, especially the way your rash looks. However, to make sure, they will likely run a few tests, including:
Blood tests to look for antibodies that are common in people with celiac disease. These antibodies are called anti-endomysial antibody (EMA), anti-deamidated synthetic gliadin-derived peptide (DGP), and anti-tissue transglutaminase (tTG). If you test positive for these antibodies, then it's very likely that you have celiac disease, and a key part of your treatment will be to avoid gluten.
A skin biopsy to look for an antibody called immunoglobulin A (IgA) in and around the skin of your rash.
- Rarely, an intestinal biopsy to look for damage in your small intestine. Your doctor doesn't usually need to do this to diagnose dermatitis herpetiformis because they can diagnose it from your symptoms and the results of your blood test and skin biopsy. But, if the results from your blood tests and skin biopsies don't match up, your doctor may want to do an intestinal biopsy to be sure.
Dermatitis Herpetiformis Treatment and Home Remedies
Your doctor will likely treat you in a couple of different ways:
1. Suggest a strict gluten-free diet. This will eventually clear up your skin and thus reduce your need to take medicine for the itch.
It has other benefits, too. Most people who have dermatitis herpetiformis also have the autoimmune condition celiac disease.
If you have one autoimmune condition, you have a higher risk of getting another. Some autoimmune conditions you may have a higher risk of getting include:
Thyroid disorders (like Hashimoto's thyroiditis or Graves' disease)
Pernicious anemia (a condition where your body can't absorb vitamin B12)
Type 1 diabetes (when your body stops making insulin)
But if you have celiac disease, you can help lower your risk of getting other autoimmune conditions by following a gluten-free diet. A gluten-free diet will also prevent the damage that gluten can cause to your intestines when you are sensitive to it. This will improve your ability to absorb the nutrients from your food and lower your risk of getting intestinal lymphoma, a type of cancer that people with celiac disease are at high risk of getting.
Following a strict gluten-free diet is the only at-home treatment that will work for dermatitis herpetiformis. However, it may take several months on a gluten-free diet for your skin to clear up. So, your doctor will likely also prescribe medicine to help you until then.
2. Prescribe dermatitis herpetiformis medications. Medications can help soothe your rash, but there's no cure for it.
Your doctor might prescribe dapsone, an antibiotic, which you take by mouth. It usually gets rid of your itching and bumps within 1-3 days. You will have regular blood tests while you're taking dapsone, especially at first. Some people have a serious reaction to dapsone. You're more likely to have a reaction if you have glucose-6-phosphate dehydrogenase (G6PD) deficiency. G6PD deficiency is a genetic condition where your body doesn't make enough of an enzyme that keeps your red blood cells from breaking down. So, your doctor may test your G6PD activity before they prescribe dapsone. If you have G6PD deficiency, they may prescribe a medicine called cimetidine, which can help prevent a reaction to dapsone.
Your doctor may also recommend a steroid cream for your skin, such as betamethasone or clobetasol, to help with itching.
Some people need to take dapsone for 1-2 years to keep their skin clear, but many people can stop using dapsone if they stay on a strict gluten-free diet.
If dapsone doesn't work for you or if you can't take it because you had a serious reaction, your doctor may prescribe you sulfa drugs, such as sulfamethoxypyridazine, sulfapyridine, or sulfasalazine. If those don't work, your doctor may try immunosuppressant drugs, such as:
Cyclosporine A or azathioprine
No matter the medicine your doctor prescribes, you still need to avoid all sources of gluten.
If you're strictly gluten-free and you have flare-ups of your dermatitis herpetiformis, you may want to see a gastroenterologist (a specialist in the stomach and intestines) with expertise in celiac disease. One cause could be a high iodine intake. Iodine is a mineral your body needs for your thyroid to function. Your thyroid controls your ability to metabolize food. You get iodine from seafood, dairy, grains, eggs, and iodized salt. Some doctors have reported that eating foods with lots of iodine can worsen your dermatitis herpetiformis symptoms. Because iodine is something your body needs, you shouldn't try to cut iodine out of your diet. This is why you may want to see a specialist who can help you figure out what's causing your flare-ups.
Living With Dermatitis Herpetiformis
It can be challenging to adapt to a gluten-free diet. But avoiding gluten will improve the rashes that can make it hard for you to focus during the day or sleep at night. When you live gluten-free, you may also be able to stop taking medicine. Some people also go into remission, which is when your symptoms go away completely for a while.
You may need to see several specialists to help you manage your condition. For instance, a gastroenterologist can help with your digestive issues, and a dermatologist can help solve your skin issues. You may also want to see a dietitian, who can help you find sources of gluten in your favorite foods and then search out alternatives.
Here are some dermatitis herpetiformis self-care tips that experts recommend to help you get started on your gluten-free life:
Focus on eating whole foods without gluten that you love. This could include vegetables, fruits, poultry, meat, fish, eggs, dairy, beans, nuts, and seeds. You can also eat grains that don't have gluten, such as quinoa, rice, and corn. Watch out for processed foods because these often have additives, flavors, and other ingredients that may make them unsafe for you to eat.
Make a list of all the foods with gluten you think you'll miss. You can often find specialty gluten-free foods to replace these. Many people follow a gluten-free diet these days, so there are plenty of products and recipes available to help you find new gluten-free favorites. If you're having trouble here, a dietician will probably have some helpful ideas and resources.
Take care when you eat out. Many restaurants will advertise that they have gluten-free options, but you want to make sure there's no cross-contamination with their regular menu items. Call restaurants ahead of time and tell them that you have celiac disease. Confirm that they have truly gluten-free options available on their menu because if you eat it, you'll get very sick. Until you find a reliable set of restaurants, you may need to cut down on how often you eat out.
Take your diet overhaul in steps. It's unreasonable to think that you'll completely change your diet overnight. Make steady steps to remove gluten from your diet and take time to adjust to your new way of eating. Dermatitis herpetiformis can be uncomfortable, but it's not dangerous. You have time to find what works for you in your life. Eventually, you will adjust so that you can live your best gluten-free life and kiss those itchy rashes goodbye.