Navrazhina K, Garcet S, Frew JW, et al. - In comparison to psoriasis, hidradenitis suppurativa (HS) has a higher inflammatory profile and is more widely distributed. Proteins that are associated with disease severity may act as disease mediators. Perilesional skin is similarly inflamed to lesional skin, implying that treatment should extend beyond skin nodules.

• Olink high-throughput proteomics was used to examine 92 inflammatory biomarkers in HS (n = 13), psoriasis (n = 11) and control skin (n = 11).

• In comparison to healthy controls, 57 differentially expressed proteins (DEPs) were found in lesional psoriasis skin and 64 DEPs in lesional HS skin.

• Th1 and Th17 proteins were found to be significantly upregulated in both HS and psoriasis lesional skin.

• In comparison to healthy controls, healthy-appearing perilesional HS skin had 63 DEPs.

• When compared with healthy controls, nonlesional HS and psoriasis skin had 24 and 7 DEPs, respectively.

• TNF and 8 other proteins were found to be significantly related to clinical severity in perilesional skin (2 cm from a nodule).