Adequate Training Required to Optimize Classification of Patients With HS

Symptoms and Presentation
Symptoms and Presentation
Investigators evaluated 5 patients previously diagnosed with hidradenitis suppurativa at various stages of severity using 4 different classifications of assessment.

Adequate bedside training sessions are necessary to optimize intrarater agreement (IAA) when classifying the skin condition hidradenitis suppurativa (HS), or acne inversa, according to a study results published in the British Journal of Dermatology.

A group of researchers investigated the degree of consensus among HS raters (the interrater agreement [IEA]) and consistency of the ratings given by each individual rater (the IAA) using 4 commonly used classification systems for HS: Hurley score, Refined Hurley staging, International HS Severity Scoring System (IHS4), and HS Physician’s Global Assessment (HS-PGA).

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In this prospective study, 32 different physicians assessed 5 patients previously diagnosed with HS at various stages of severity were assessed by 32 different physicians using the 4 methods listed above at the Wroclaw Medical University in Wroclaw, Poland, during a 2-day educational event.

IHS4 and HS-PGA achieved high IEA scores throughout the trial. IEA scores overall improved throughout the trial, reinforcing the effect that training and HS-rating experience can have. A good IAA was found among all classification methods, although the simpler 3-step methods, IHS4 and Hurley score, scored highest in this category.

The researchers concluded, “Our results illustrate the difficulty of HS classification by a simple rater evaluation of physical signs. Adequate training is required for optimizing IAA.”

They recommended that the same individual assess each patient’s baseline and end point for consistency, especially if lesion count-based systems are used in end point evaluation. They also recommended the IHS4 and HS-PGA methods as the most reliable systems for the classification of patients with HS.

Multiple authors declared competing interests. Please refer to reference for a complete list of authors’ disclosures.


Zouboulis CC, Matusiak L, Jemec GBE, et al. Interrater and intrarater agreement and reliability in clinical staging of hidradenitis suppurativa/acne inversa [published online April 10, 2019]. Br J Dermatol. doi: 10.1111/bjd.17982