Dermatitis Herpetiformis or DH is a rash. It is not a form of herpes even though it sounds a lot like herpes. It is a red, blistery, itchy rash that is associated with gluten consumption. We are going to talk all about DH today because I think there are lots of misconceptions about what it is and how it is related to Celiac.
I always though that Celiac and DH were the same. They are not. They are related – in that they have the same trigger – gluten. But they are different diseases with different treatment options.
Dermatitis herpetiformis is an intensely itching and blistering rash. According to the National Institute of Diabetes and Digestive and Kidney Disorders (NIH), ” characterized by small, clustered papules and vesicles that erupt symmetrically on the elbows, knees, buttocks, back, or scalp.” A papule is a small, raised, solid pimple or swelling, often forming part of a rash on the skin and typically inflamed but not producing pus. So it looks like weeping blisters on a red patch, typically on both sides of the body that does not produce pus.
DH is often confused with eczema. The location and symmetry of the rash should be a red flag for doctor or medical professions regarding differentiating between DH or eczema. A biopsy of the rash will show IgA antibodies in the epidermis (skin) which is indicative of DH.
Celiac blood panels and small intestinal biopsies may not show positive if a person only has DH. Only about 10% of the people with diagnosed with Celiac develop DH. Less than 20% of those with DH, develop gastrointestinal symptoms similar to Celiac disease. In only 25%-35% of DH sufferers, their TtG IgA will be positive but over 90% will show normal villi and significantly increased intraepithelial lymphocytes upon endoscopic biopsy.
DH is caused by gluten ingestion. The body attacks the gluten and instead of attacking the villi in the gut, it attacks the skin. Dapsone is used as a temporary treatment until the gluten free diet can take hold. DH is not triggered by topical gluten application. Gluten must be ingested before DH is triggered. If someone is experiencing topical gluten reactions, it may be something other than gluten triggering the reaction.
DH seems to come in flares. A flare is where the rash erupts, the blisters weep, and potentially more blisters replace the ones that were there before and the cycle continues.
DH can go into remission. If after 2 years of no medicine and a return to a gluten containing diet, the DH is considered in remission. How awesome is that?!!
If you haven’t had DH diagnosed and have Celiac, it is unlikely you have the celiac rash.
Hopefully this clears up some things about DH. I know it is a common topic of discussion and I wanted to shed some light on it.
PS – I’m not a doctor nor should anything posted on this site be construed as medical advice. My research is done on commonly available resources and I just look this stuff up.