Dermatitis Herpetiformis (DH)

Dermatitis Herpetiformis (DH) is a chronic autoimmune skin condition caused by a sensitivity to gluten - the same protein that triggers celiac disease. In DH, the immune system deposits antibodies in the skin, causing an extremely itchy, blistering rash, often in symmetrical patches on the elbows, knees, buttocks, back, or scalp. It is considered a skin manifestation of celiac disease, and nearly everyone with DH also has gluten sensitivity in the small intestine.

Groups of small, red bumps or blisters; Intense itching or burning before rash appears; Symmetrical distribution commonly on elbows and knees, buttocks, lower back, scalp; Lesions often come and go, sometimes leaving discoloration; May be accompanied by digestive symptoms if celiac disease is active.

Autoimmune reaction to gluten in genetically susceptible individuals. When gluten is eaten, the body produces IgA antibodies to attack gluten. These antibodies mistakenly target the enzyme tissue transglutaminase (tTG) in the intestines. A related enzyme in the skin (epidermal transglutaminase) becomes the target, triggering the rash.

Skin biopsy with direct immunofluorescence (to detect IgA deposits); Blood tests: Anti-tissue transglutaminase (tTG) antibodies, Anti-endomysial antibodies (EMA), Anti-deamidated gliadin peptide (DGP); Celiac testing (intestinal biopsy or serology); Improvement on a gluten-free diet is often considered confirmatory.

Strict lifelong gluten-free diet - the only way to stop immune activation; Dapsone - an antibiotic that provides quick rash relief but does not treat the underlying cause (requires regular blood monitoring due to side effects); Topical steroids may be used for symptom relief; Nutritional support for vitamin deficiencies if present.

Excellent with gluten-free diet - rash and intestinal damage usually improve within weeks to months. Without dietary changes, long-term risks include intestinal damage, malnutrition, and increased cancer risk (especially intestinal lymphoma).

Estimated at 10 per 100,000 people. More common in men, usually appears between ages 20 and 40. Seen more often in people of Northern European descent.