Background: Psoriasis affects 1-3% of the Canadian population. Psoriatic arthritis (PsA), the most common comorbidity of psoriasis, affects up to 30% of psoriasis patients. The skin microbiome is hypothesized to play a role in the pathogenesis of psoriatic disease (PsD-psoriasis and PsA).
Objective: To summarize the current state of literature on the skin microbiome in PsD.
Methods: A systematic review was performed using searches in Ovid, Medline, Embase, Medline Epub Ahead of Print and In-Process & Other Non-Indexed Citations, and Cochrane Central Register of Controlled Trials (CENTRAL). Search was limited to humans and English language, with no limits for date or publication type.
Results: Of 4,032 citations identified, 9 studies met inclusion criteria (7 on psoriasis only and 2 studies compared the microbiome characteristics between psoriasis and PsA). Compared to healthy controls, lesions demonstrated a decreased alpha diversity, higher relative abundances of Firmicutes, and lower relative abundances of Actinobacteria. Less conclusive were genus-level results, which nonetheless demonstrated trends towards increased Streptococcus, Staphylococcus, and Corynebacterium and decreased Propionibacterium in lesions vs. control.
Limitations: Study designs were heterogeneous, including sampling technique and exclusion criteria.
Conclusions: Phyla- and selected genus-level characteristic of the psoriatic microbiome are presented; further research is warranted.
Keywords: Next-generation sequencing; Psoriasis; Psoriatic arthritis; Skin microbiome; Systematic review.
© 2019 The Author(s).