The human microbiome in immunobullous disorders and lichen planus.

For several decades, there has been a significant growth in the incidence of autoimmune diseases. Studies indicate that genetic factors may not be the only trigger for disease development and that dysbiosis of the microbiome may be another mechanism involved in the pathogenesis of autoimmune diseases. The role of the microbiome in the development of common skin disorders such as psoriasis, atopic dermatitis, acne and rosacea is increasingly well understood. However, few studies have focused on lichen planus and the rare acquired immunobullous diseases, both mucocutaneous groups of disorders linked to skin, oral and gut microbiomes. This review provides an insight into the current understanding of how the microbiome may contribute to the development of autoimmunity and to the maintenance and exacerbation of acquired immunobullous and lichenoid diseases. These mechanisms may have implications for future preventive and therapeutic approaches.