Dermatitis herpetiformis

Dermatitis herpetiformis (DH) is a chronic autoimmune blistering skin condition, characterised by blisters filled with a watery fluid that is intensely itchy. DH is a cutaneous manifestation of Coeliac disease. Despite its name, DH is neither related to nor caused by herpes virus: the name means that it is a skin inflammation having an appearance similar to herpes. Dermatitis herpetiformis (DH) is a chronic autoimmune blistering skin condition, characterised by blisters filled with a watery fluid that is intensely itchy. DH is a cutaneous manifestation of Coeliac disease. Despite its name, DH is neither related to nor caused by herpes virus: the name means that it is a skin inflammation having an appearance similar to herpes. Dermatitis herpetiformis was first described by Louis Adolphus Duhring in 1884. A connection between DH and Coeliac disease was recognized in 1967, although the exact causal mechanism is not known. The age of onset is usually about 15–40, but DH also may affect children and the elderly. Men are slightly more affected than women. Estimates of DH prevalence vary from 1 in 400 to 1 in 10,000. It is most common in patients of northern European/northern Indian ancestry, and is associated with the human leukocyte antigen (HLA) haplotype HLA-DQ2 or HLA-DQ8 along with coeliac disease and gluten sensitivity. Dermatitis herpetiformis is characterized by intensely itchy, chronic papulovesicular eruptions, usually distributed symmetrically on extensor surfaces (buttocks, back of neck, scalp, elbows, knees, back, hairline, groin, or face).:616 The blisters vary in size from very small up to 1 cm across. The condition is extremely itchy, and the desire to scratch may be overwhelming. This sometimes causes the sufferer to scratch the blisters off before they are examined by a physician. Intense itching or burning sensations are sometimes felt before the blisters appear in a particular area. The signs and symptoms of DH typically appear around 30 to 40 years of age, although all ages may be affected. Although the first signs and symptoms of dermatitis herpetiformis are intense itching and burning, the first visible signs are the small papules or vesicles that usually look like red bumps or blisters. The rash rarely occurs on other mucous membranes, excepting the mouth or lips. The symptoms range in severity from mild to serious, but they are likely to disappear if gluten ingestion is avoided and appropriate treatment is administered. Dermatitis herpetiformis symptoms are chronic, and they tend to come and go, mostly in short periods of time in response to the amount of gluten ingested. Sometimes, these symptoms may be accompanied by symptoms of coeliac disease, which typically include abdominal pain, bloating or loose stool, weight loss, and fatigue. However, individuals with DH often have no gastrointestinal symptoms even if they have associated intestinal damage. The rash caused by dermatitis herpetiformis forms and disappears in three stages. In the first stage, the patient may notice a slight discoloration of the skin at the site where the lesions appear. In the next stage, the skin lesions transform into obvious vesicles and papules that are likely to occur in groups. Healing of the lesions is the last stage of the development of the symptoms, usually characterized by a change in the skin color. This may result in areas of the skin turning darker or lighter than the color of the skin on the rest of the body. Because of the intense itching, patients usually scratch, which may lead to the formation of crusts. In terms of pathology, the first signs of the condition may be observed within the dermis. The changes that may take place at this level may include edema, vascular dilatation, and cellular infiltration. It is common for lymphocytes and eosinophils to be seen. The bullae found in the skin affected by dermatitis herpetiformis are subepidermal and have rounded lateral borders. When looked at under the microscope, the skin affected by dermatitis herpetiformis presents a collection of neutrophils. They have an increased prevalence in the areas where the dermis is closest to the epidermis.