What counts? The relationship between patient estimated numbers of painful hidradenitis suppurativa lesions over 4 weeks compared with clinician's lesion count at the time of examination

Hidradenitis suppurativa (HS) is a chronic disease where recurrent painful nodules, abscesses and/or tunnels/sinus tracts develop in inverse regions of the skin 1 . Clinical assessment and patient experience is used to monitor disease severity and progression during treatment. However, clinical assessment is not standardized and can be challenging 2 . The HIdradenitis SuppuraTiva cORe outcomes set International Collaboration (HISTORIC), an international multi-stakeholder and collaborative patient/physician driven group has proposed a universal core outcome set for HS clinical trials 3-5 , and a specific HS quality of life questionnaire has been validated 6 . Both constitute important endeavors as prior inadequately validated outcome-measures have made meta-analysis and other systematic data extraction difficult.