After multivariate logistic regression analysis, age (p < 0.001), bacterial infection (p = 0.005), MYOACT score (p = 0.009), Interleukin (IL)-17A (p = 0.017), anti-SRP antibody (p = 0.011) and steroid monotherapy (p = 0.001) were identified as factors significantly associated with PAH in IIM patients. This evidence concerns the gene IL17A and bacterial infectious disease.