What is Dermatitis Herpetiformis (DH)?
Dermatitis herpetiformis (DH) is a severe, itchy, blistering skin rash. DH is a chronic condition that is considered to be the skin form of celiac disease. Not all people with celiac disease develop DH. The rash usually occurs on the elbows, knees, and buttocks and it is typically symmetrical, meaning it appears on both sides of the body. When the rash goes away, which it often does spontaneously, it may leave brown or pale marks on the skin where pigmentation is lost.
Skin contact with gluten-containing foods and products has not been shown to cause outbreaks.
Who Gets Dermatitis Herpetiformis?
- About 15-25% of individuals with celiac disease experience DH
- DH affects more men than women
- DH generally starts in adulthood. It's not common to see DH in children, but it can occur
- Only about 20 percent of people with DH have intestinal symptoms of celiac disease, however biopsies show that 80 percent have some degree of damage to the small intestine, especially if a high gluten diet is maintained
How is Dermatitis Herpetiformis Diagnosed?
Doctors diagnose DH by examining the cells under the top layer of skin, known as the dermal papillae, for neutrophils and granular IgA deposits in the skin. These types of skin samples are collected by performing a biopsy. DH can often be misdiagnosed and frequently confused with skin conditions such as allergies, bug or mosquito bites, contact dermatitis, diabetic pruritus, eczema, herpes, hives and psoriasis. While 70-80% of DH patients have higher than normal blood IgA- tTG antibody levels, a typical celiac blood test is not considered sufficient or reliable enough to properly diagnose patients.
How is Dermatitis Herpetiformis Treated?
DH is treated with a lifelong gluten-free diet, just like celiac disease. The skin's response to the gluten-free diet is much slower compared to the healing of the intestines with celiac disease. It may take about six months to achieve some improvement in the skin condition and up to two years or more to get total control through the gluten-free diet alone. The rash symptoms can be controlled with medications, such as Dapsone. In general, itching and new lesions will begin to subside within 48-72 hours of starting Dapsone. However, this medication does not treat the intestinal condition, meaning that people with DH should also maintain a strict lifelong gluten-free diet.
What is the Connection between Dermatitis Herpetiformis and Celiac Disease?
DH is a skin manifestation of celiac disease and is part of the abnormal immune response to gluten.
Where Can I Learn More?
Do you or a family member suffer from dermatitis herpetiformis? You may have celiac disease. Find out now. Take our Celiac Disease Symptoms Checklist.