The cutaneous and intestinal microbiome in psoriatic disease.

Psoriasis (PsO) and psoriatic arthritis (PsA) are chronic immune-mediated inflammatory diseases of multifactorial etiology. In addition to genetic and environmental factors, evidence supports involvement of a dysregulated human microbiome in the pathogenesis of psoriatic disease. In particular, alterations in the composition of the microbiome, termed dysbiosis, can result in downstream proinflammatory effects in the gut, skin, and joints. Both the cutaneous and intestinal microbial populations are implicated in the pathogenesis of psoriatic disease, although exact mechanisms are unclear. Herein, we review the relationship between the human microbiome and psoriatic disease. Further insight into the functions of the microbiome may allow for greater understanding of inflammatory disease processes and identification of additional therapeutic targets.

Successful Management of Anti-TNF-Induced Psoriasis Despite Continuation of Therapy in a Pyoderma Gangrenosum Patient

Pyoderma gangrenosum is an inflammatory, neutrophil-mediated disorder that is difficult to treat. Tumor necrosis factor and other inflammatory mediators are among the most promising therapeutic targets. We present a case of a 60-year-old woman with recalcitrant pyoderma gangrenosum treated with adalimumab, who paradoxically developed psoriasis. Secukinumab, an interleukin-17 inhibitor, was added to her regimen, resulting in successful treatment of her psoriasis. Secukinumab was later replaced by methotrexate, resulting in remission of both pyoderma gangrenosum and maintenance of a psoriasis-free state. We conclude that paradoxically induced psoriatic lesions can resolve with adjunct therapy despite continuation of anti-tumor necrosis factor agents. J Drugs Dermatol. 2020;19(2)199-201. doi:10.36849/JDD.2020.4662