Khalid, Bisma

AbstractBackgroundThe hidradenitis suppurativa (HS) clinical response (HiSCR) has come under scrutiny as several HS clinical trials failed to meet primary endpoints with high placebo responses. This may be due to limitations of the tool and raters' ability to accurately characterize and count lesions, rather than lack of efficacy of the studied drug. Due to HS lesion complexity and potential differences in rater training, it was hypothesized that there would be discrepancies in how providers characterize and count lesions for HS clinical trials.ObjectiveTo evaluate how HS providers and patients name and count HS lesions and to identify discrepancies among providers to initiate the development of consensus‐driven guidance for HS rater training.MethodsAn online survey was distributed to the members of HIdradenitis SuppuraTiva cORe outcomes set International Collaboration (HISTORIC). Respondents were asked to classify lesion images composed of multiple and different morphology types and answer questions regarding inclusion of associated dermatological conditions.ResultsForty‐seven HISTORIC members responded (29 providers; 18 patients). There was variability in how respondents classified HS lesions. Of 12 questions containing images, four had ≥50% of respondents choosing the same answer. With an image of a lesion composed of different morphologies, 45% of providers counted it as a single lesion and 45% counted it as multiple distinct lesions. With an image of multiple interconnected draining tunnels, 7% of providers classified it as a single draining tunnel while 79% categorized it as multiple draining tunnels with the number estimated by visual inspection. There was also variability in deciding whether lesions occurring in associated conditions should be considered separately or included in HS lesion counts. Patient responses were also variable.ConclusionsThe result of the current study reaffirms the gap in how providers characterize and count HS lesions for clinical trials and the need to develop consensus‐driven rater training related to HS outcome measures.

Current validated hidradenitis suppurativa (HS) severity assessment tools are time-consuming and impractical in fast-paced, ambulatory clinic settings. This study evaluated the construct validity of the most severe or ‘worst’ area local Hidradenitis suppurativa Activity and Severity Index-Revised (W-HASI-R) as a novel target area assessment tool for clinical setting use. W-HASI-R had strong association with the International Hidradenitis Suppurativa Severity Score System and abscess and nodule count, moderate association with Hurley stage and HS physician global assessment and weak, negative association with reverse-scored Dermatology Quality Life Index. The resulting data suggest that W-HASI-R may be an option as an efficient target area assessment tool for fast-paced, ambulatory settings.

Skin thickness, as known as inflammatory induration, is a component in several HS grading instruments including the HASI and HASI-R. This study sought to evaluate how thickest lesion measurement (mm) corresponds to HS severity. This study demonstrates that inflammatory induration has moderate association with HS severity, thickest lesion measurement (mm) demonstrates known-validity across Hurley stages, and cut-offs for thickest lesion measurement (mm) were determined for inflammatory induration grading for the purpose of HASI-R training.