Dermatitis Herpetiformis

Dermatitis Herpetiformis1

Dermatitis Herpetiformis2

General Information
Dermatitis Herpetiformis is an autoimmune disease causing clusters of intensely pruritic small blisters and hive like swellings. Despite the name, dermatitis herpetiformis is not related to the herpes virus. Prior to the blisters forming the area usually has a burning feeling. In around one to two weeks, the blisters will scab and heal, but new spots continue to appear. Dermatitis herpetiformis are located on the extensor surfaces of the elbows, knees, buttocks, and back; at times blisters break out on the face and neck. The rash is caused when gluten in the diet combines with IgA (Immunoglobulin A is an antibody playing a critical role in mucosal immunity), and together they enter the blood stream and circulate, eventually clogging up the small blood vessels in the skin. This attracts white blood cells and releases powerful chemicals called complements that create the rash. Iodine is required for the reaction, so people with DH should avoid using Iodized salt. Limiting intake of wheat, barley, or rye products can lessen the symptoms. Dapsone (diaminodiphenyl sulfone) and sulfapyridine are the primary medications used to treat DH. Dapsone may have adverse effects, so weekly or bi-weekly blood tests will be needed.

Epidemiology
US study showed a prevalence of 11.2 cases per 100,000 population

Etiology
Cause is unknown although linked to gluten sensitivity, a protein found in wheat and some other grains

Pathogenesis
Small blisters develop gradually mostly on the elbows, knees, buttocks, lower back, and back of the head

Clinical
Small, clustered vesicles are symmetrically distributed over extensor surfaces

Histology
Neutrophils in the dermal papillae, with fibrin deposition, neutrophil fragments, and edema

Bibliography
1 .”Dermatitis Herpetiformis” (Online) http://www.aocd.org/skin/dermatologic_diseases/dermatitis_herpeti.html (visited: March 16, 2008) 2. “Dermatitis Herpetiformis” (Online). May 2007. http://www.emedicine.com/derm/topic95.htm (visited: March 16, 2008)

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