Interleukin-17 is important in initiation and maintenance of many autoimmune reactions and it is involved in production of proinflammatory cytokines, matrix metalloproteinases, neutrophils, and eosinophils, all of which are important pathogenic factors in bullous pemphigoid and dermatitis herpetiformis [19]. This evidence concerns the gene IL17A and dermatitis herpetiformis.