Interest in hidradenitis suppurativa (HS) has exploded in the last few years. A PubMed search of articles indexed for MEDLINE using the MeSH term hidradenitis suppurativa yielded more than 900 articles on HS since 1947, with a sharp increase in publications over the last few years and 119 articles published in 2015 alone. In addition to publications, we recently saw adalimumab become the first and only US Food and Drug Administration–approved treatment of moderate to severe HS.
With new treatment options and enthusiasm for HS, further attention needs to be paid to the scoring systems or outcome measures that clinicians use to grade HS severity and disease. Utilization of validated outcome measures allows for comparability between treatment effects, which is essential for clinical trials, meta-analyses, and monitoring of treatment response in daily clinical practice. Designing a scoring scale for any dermatologic disease is challenging; however, as we move forward with value-based reimbursement models, we likely will encounter quality reporting guidelines that mandate providers demonstrate the positive impact of treatment. Thus, scoring systems for HS, particularly ones that accurately assess this impact of treatment, are essential. For psoriasis, the physician global assessment (PGA) and psoriasis area and severity index are standard outcome measures of disease severity in clinical trials. The PGA also can be used in a clinical setting to longitudinally track patient treatment outcomes.1 Both the psoriasis area and severity index and PGA were cited as acceptable scoring tools for Medicare’s Physician Quality Reporting System quality metrics reporting (Measure #410: Psoriasis: Clinical Response to Oral Systemic or Biologic Medications). Unfortunately, no such outcome measures consensus currently exists for scoring systems in HS.
Many scoring systems have been proposed for HS. The most well known is the Hurley staging system. Developed in 1989 for surgical approaches, it is a straightforward tool to categorize disease severity but does not emphasize the inflammatory component of HS. Recently, a refined Hurley stage classification system was proposed. This 3-step algorithm expanded the Hurley stage classification to incorporate disease extensiveness, degree of inflammation, and presence of sinus tracts.2 The modified Sartorius score (also known as the modified HS score) is a more detailed scoring system for assessing disease activity that requires measurements and precise counting of lesions.3 The HS-PGA is an ordinal scale specific to HS that categorizes patients into clear, minimal, mild, moderate, severe, or very severe disease, and it was used successfully in a phase 2 interventional clinical trial.4 The HS clinical response (HiSCR) score is an HS-specific, binary scoring system for patients with 3 or more abscesses or inflammatory nodules. It was engineered using raw data and outcomes from a large clinical trial, and subsequently was employed as the primary end point in 2 randomized controlled trials.5,6 It is the only HS scoring system to undergo an extensive validation process of both physician- and patient-reported measures for assessment of therapeutic response in controlling the inflammatory manifestations of HS.