TNF and histiocytic sarcoma: The inverse association between biologic treatment (anti-TNF) and the risk of developing HS flares was further confirmed though the multivariable logistic regression analysis (adjusted odds ratio [aOR] = 0.14, 95% confidence interval [CI] 0.04–0.50; p = 0.002), indicating that biologic treatment may provide a protection against HS flares (Table 4).