Pustulotic arthro-osteitis (PAO) is a significant comorbidity of palmoplantar pustulosis (PPP), with biologics targeting tumor necrosis factor (TNF)-α, interleukin (IL)-12/23 p40, IL-23 p19, and IL-17 showing clinical benefits for PPP/PAO. This evidence concerns the gene IL17A and palmoplantar pustulosis.