LAUSR

day [Hurley staging axillary and gluteal region: intraclass correlation (ICC) = 0 72, 95% CI 0 6–0 8; Hurley staging groin: ICC = 0 55, 95% CI 0 4–0 7). These results are similar to what has been reported previously, e.g. for atopic eczema and acne intruments. Accordingly, in terms of inter-rater reliability, it seems reasonable to conclude that the Hurley classification system is an acceptable instrument for staging in HS. But does this imply that the Hurley classification system is also a well-suited instrument for severity staging in HS? HS is a many-sided disease which may be associated with significant individual morbidity and can have severe consequences. Therefore, the HIdradenitis SuppuraTiva cORe outcomes set International Collaboration (HISTORIC)’s first consensus study established that future clinical trials in HS should measure pain, HS-specific quality of life, global assessment, progression of course and symptoms alongside with physical signs. By nature, the core outcome set (COS) focuses on dynamic outcomes to capture and assess the effect of interventional trials. Hence, the COS is not intended for severity staging, e.g. for treatment guidance. Nevertheless, patients and experts from 19 countries across four continents did agree that physical signs is not the only important core outcome. So, is Hurley classification, which revolves around physical signs exclusively, enough for severity staging in HS? With the number of ongoing trials in HS, which most likely will increase future treatment options, the need for a global consensus on how to define mild, moderate and severe HS will only increase. Therefore, the above question does seem to call for an organized debate in the HS community and maybe even a new consensus study involving, of course, the voices of patients living with HS.