 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).The blisters vary in size from very small up to 1 cm across.