Key Data Elements for Hidradenitis Suppurativa: Consensus Recommendations for Clinical and Research Practices

To the Editor,

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disease affecting 0.1% to 4% of the global population.^1,2 Despite major advancements in therapeutic strategies, there is no standardized data collection system for clinical care and research efforts. ³ This inconsistency hinders the analysis, comparison, and pooling of data on patient demographics and treatment effectiveness in HS.^3,4 The objective of this study is to establish expert consensus on core data items for use in real-world clinical care and research. These recommendations aim to standardize data practices, support high-quality patient care, and facilitate the development of a future national registry for HS patients.

An anonymous Delphi approach, ⁵ conducted via the Welphi platform, was used to gather consensus from dermatologists with HS expertise on essential data items related to patient demographics and treatment effectiveness. The questionnaire consisted of 75 data items across 9 domains. Participants rated each item as “Should not be collected,” “Optional,” or “Mandatory,” with space in each section for additional comments or suggestions. Consensus was defined as over 70% of respondents in agreement with “Optional” or “Mandatory.”

Ten participants completed the survey (75.0% response rate), reaching consensus in the first round on all 75 agreed-upon items that should be routinely included in databases for clinical care and research purposes. Supplemental Table 1 shows a summary of the Delphi exercise for all 75 items in the 9 domains. Data elements were broadly divided into (i) patient demographics, (ii) treatments, (iii) medications, (iv) procedures, (v) medical history, (vi) social history, (vii) physical exam, (viii) patient-reported outcomes, and (ix) response to therapy/disease activity.

Participants unanimously (100%) agreed that the following 22 items are “Mandatory” to be collected: gender; year of disease onset; current treatment(s) for HS; treatment outcomes; medications: IV ertapenem, metformin, adalimumab, secukinumab; procedures: wide local excision; medical history: diabetes, dyslipidemia, obesity, depression, Crohn’s disease, ulcerative colitis, or inflammatory bowel disease, psoriasis, and pilonidal sinus; social history: cigarette smoking, marijuana use; physical exam: affected sites, Hurley stage, lesion count; and patient-reported pain score.

The greatest discrepancy pertained to the inclusion of the International Hidradenitis Suppurativa Severity Score System (IHS4), with 80% of participants deeming it “Optional.” Additional discrepancies were regarding the inclusion of alexandrite laser under Procedures (60% Optional), cephalexin, trimethoprim-sulfamethoxazole, and methotrexate under Medications (60% Optional), and marital status under Social History (60% Optional). Experts identified other items deemed essential for data collection. Four further data items were recommended for inclusion under the Procedures domain: (1) laser, not otherwise specified; and (2) wide lesion excision, categorized into (i) primary healing with flap, (ii) primary healing without flap, and (iii) secondary intention healing. Furthermore, it was suggested that both IHS4 and the Hidradenitis Suppurativa Clinical Response (HiSCR) may be unnecessary, as they could be retrospectively calculated from lesion count data.

This study successfully established a consensus among experts on the core data items that should be routinely collected in clinical care and research for HS. This work is an important step toward harmonizing HS data infrastructure and promoting collaborative, comprehensive data collection to address gaps in both clinical care and evidence-based research.