Position Statement of the EADV Task Forces With External Experts on Quality of Life Measurement in Hidradenitis Suppurativa: An Update

ABSTRACT

Hidradenitis suppurativa (HS) has a profound negative impact on patients' Quality of Life (QoL). The European Academy of Dermatology and Venereology (EADV) Task Force (TF) on QoL and Patient Oriented Outcomes and TF on Acne, Rosacea and Hidradenitis Suppurativa (ARHS), together with external experts, decided to provide an updated position statement on QoL measurement in HS. In our previous position statement on HS, we stated that a Dermatology Life Quality Index (DLQI) score of 0–1, corresponding to no effect on patient's life according to the DLQI banding descriptions, may be considered as a difficult to reach but important treatment goal: achievement of this goal has since been used as an efficacy criterion in several clinical trials. For many HS treatment methods, there is still a lack of well‐organized randomized clinical trials with sufficient participant numbers in which QoL instruments have been used as outcome measures. The DLQI is the most widely used QoL instrument in HS. Clinical recommendations and treatment efficacy are based on its score grading system and minimal clinically important difference (MCID). The HS‐specific QoL instruments HSIA, HSQoL‐24, HiSQOL, and QoL‐HS have a satisfactory number of items for routine clinical use and short recall periods. HiSQOL and HSQoL‐24 have score grading systems and the MCID for HiSQOL has been established. The TF on QoL and Patient Oriented Outcomes and TF on ARHS recommend that QoL be assessed in HS: dermatology‐specific and HS‐specific instruments may be used alongside each other.

The European Academy of Dermatology and Venereology (EADV) Task Forces on Quality of Life and Patient Oriented Outcomes and Acne, Rosacea and Hidradenitis Suppurativa, together with external experts, provided an expert update/position statement on QoL measurement in HS based on a narrative literature review and expert opinion.

1. Introduction

Hidradenitis suppurativa (HS) is an under‐diagnosed and under‐treated disease with a profound negative impact on patients quality of life (QoL) [1]. Patients with HS may be victims of stigmatization and bullying [2]. HS can affect QoL in many ways and people with HS consistently record high impact with high scores on QoL instruments [1]. The S2k guideline for the treatment of HS recommends that assessment of HS should be performed using standardized criteria to objectively record lesions into account, and to assess the disease‐related impairment of QoL [3, 4]. If no significant reduction of the inflammatory activity of the lesions or no improvement in QoL is observed after 12 weeks, the therapy should be modified while taking into account the differing rates of drug effectiveness. A validated measurement tool suitable for patient use (Patient Reported Outcome Measurement or PROM) should be used to assess impairment of QoL and pain in HS–both in clinical trials and in daily practice [3]. The eligibility criteria for biologics and advanced molecules, proposed by the European S2k guidelines for HS, included significant impairment of QoL as measured by the Dermatology Life Quality Index (DLQI) > 10 or by Quality of Life for Hidradenitis Suppurativa (HS‐QoL) > 20 [4]. The Hidradenitis Suppurativa Core Outcomes Set International Collaboration (HiSTORIC) included HS‐specific QoL as one of the core domains to measure in all HS clinical trials [5]. The number of publications mentioning QoL in HS increased from 0 to 1 year in the 2000s reaching 168 during the first 11 months of 2025 (PubMed, Figure 1). The European Academy of Dermatology and Venereology (EADV) Task Forces (TFs) on QoL and Patient Oriented Outcomes and Acne, Rosacea and HS (ARHS), together with external experts, decided to provide an updated position statement on QoL measurement in HS based on narrative literature review and expert opinion.

FIGURE 1.

The number of publications mentioning QoL in HS in PubMed.

2. Materials and Methods

The methods for identifying relevant publications were similar to those used in the preparation of the original position statement of the EADV TFs on QoL and Patient Oriented Outcomes and ARHS on the QoL measurement in HS [6] and the update on QoL in HS published in 2021 [7]. A literature search was performed using PubMed, which was searched from 2021 to November 2025 using the key word combinations: hidradenitis suppurativa, quality of life and acne inversa, quality of life. All publications written in English or those having English abstracts were considered.

Inclusion criteria articles with assessment of QoL in HS patients; studies on the development and validation of HS‐specific QoL instruments; studies where QoL was studied in HS and other diseases and results on HS were presented and/or discussed separately. Exclusion criteria: review articles, guidelines and protocols; studies without QoL assessment; measurement of QoL in conditions other than HS; studies where QoL was studied in HS and other diseases but results on HS were not presented and/or discussed separately.

All articles were primarily reviewed by the corresponding author. For those articles that fulfilled the inclusion and exclusion criteria, the study aim and design, the QoL instruments used, treatment methods (where appropriate), and the main study results related to QoL were recorded.

3. Results

The analysis of 464 publications identified seven HS‐specific QoL instruments: Quality of Life for Hidradenitis Suppurativa (HS‐QoL) [8], Hidradenitis Suppurativa Burden of Disease (HSBOD) [9], Hidradenitis Suppurativa Impact Assessment (HSIA) [10], Hidradenitis Suppurativa Quality of Life‐24 (HSQoL‐24) [11], HIDRAdisk [12], Hidradenitis Suppurativa Quality of Life (HiSQOL) [13], Quality of Life in Hidradenitis Suppurativa (QoL‐HS) [14]. Brief characteristics of these instruments are presented in Table 1.

TABLE 1.

Brief characteristics of HS‐specific QoL instruments.

Name	Short name/abbreviation	Number of items	Number of scales	Recall period	Scoring	Validation	Year of establishment
Quality of Life for Hidradenitis Suppurativa [8]	HS‐QoL	44	7 subscales: ‘physical consequences’, ‘HS symptoms’, ‘sexual activity consequences’, ‘emotional consequences’, ‘social consequences’, ‘work consequences’ and ‘social support’	Last 6 months	Five‐point scale ranging from 1 (never) to 5 (all the time)	Internal consistency and convergent validity	2017
Hidradenitis Suppurativa Burden of Disease [9]	HSBOD	19	5 domains: ‘symptoms and feelings’, ‘daily activities’, ‘leisure’, ‘work/school’ and ‘personal relationships’	Two parts with different recall periods: the last 4 weeks (14 items) and the entire time of having HS (5 items)	Visual analog scale from 0 to 10	Internal consistency and convergent validity	2018
Hidradenitis Suppurativa Impact Assessment [10]	HSIA	18	Unidimensional	Last week	Items 1–16 are scored on a 0 (no impact) to 10 (extreme impact) scale. Items 17 and 18 are not included in the HSIA total score.	Internal consistency, convergent validity, test–retest reliability	2018
Hidradenitis Suppurativa Quality of Life‐24 [11]	HSQoL‐24	24	6 domains: ‘psychosocial’, ‘economic’, ‘occupational’, ‘relationships’, ‘personal’ and ‘clinical’	Last 4 weeks	Five‐point scale ranging from 0 (never) to 4 (always)	Internal consistency, convergent validity, sensitive to change	2019
HIDRAdisk [12]	HIDRAdisk	10	Unidimensional	Not stated	Visual analog scale from 0 to 10	Internal consistency, convergent validity, test–retest reliability, sensitive to change	2019
Hidradenitis Suppurativa Quality of life [13]	HiSQOL	17	3 subscales: ‘symptoms’, ‘activity‐adaptation’ and ‘psychosocial’	Last week	Five‐point scale ranging from 0 (not at all) to 4 (extremely)	Internal consistency, convergent validity, test–retest reliability	2020
Quality of Life in Hidradenitis Suppurativa [14]	QoL‐HS	23	2 subscales: ‘social and psychological impairments’, ‘physical impairments’ and one separate item on side‐effects of the treatment	Last week	5‐point scale ranging from 0 (not at all) to 4 (very)	Internal consistency, convergent validity, sensitive to change	2023

3.1. Grading Systems and Interpretation Evidence for HS‐Specific QoL Instruments

For HiSQOL, clinically meaningful within‐patient improvement thresholds were calculated via distribution and anchor‐based methods, the latter based on a two point change in patient global impression as opposed to the smaller one point change of the minimal clinically important difference (MCID). The clinically meaningful difference was estimated as: 20–21‐point decrease for HiSQOL total score (total possible range 0–68), 5–6‐point decrease for symptoms subscale (range 0–16), 4–5‐point decrease for psychosocial subscale (range 0–20), and 10–11‐point decrease for activities‐adaptations subscale (range 0–32). Proposed severity thresholds for the HiSQOL total score are: none 0–4, mild 5–14, moderate 15–21, severe 22–23, and very severe 24–68. Severity thresholds for the three HiSQOL subscales were also proposed [15]. For the HSQoL‐24 instrument, four cut off values were proposed: 0–24, no effect; 25–32, small impairment; 32–43, moderate impairment; ≥ 44, serious impairment [16].

We analyzed the influence of different treatment methods on QoL of patients with HS in clinical trials published from 2021 and identified during our literature search.

3.2. Randomized, Double‐Blind, Placebo‐Controlled Studies

In two randomized, double‐blind, placebo‐controlled trials, the mean DLQI change in groups of patients on bimekizumab 320 mg every 2 weeks or every 4 weeks was above the DLQI MCID of 4. The mean changes in the placebo groups were below the DLQI MCID [17]. A higher proportion of bimekizumab‐treated participants reported no impact of disease on their QoL compared with placebo‐treated patients (DLQI 0/1 responder rate, 36% in bimekizumab‐treated patients and 0% in placebo‐treated patients). In a comparison of adalimumab and bimekizumab, the number of subjects treated with adalimumab reaching a DLQI score of 0/1 (meaning no effect on patient's QoL) was similar to or smaller than for those treated with bimekizumab [18]. In another randomized, double‐blind, placebo‐controlled trial, the DLQI and HiSQoL scores changes in patients that received spesolimab did not significantly differ from the score changes in the placebo group and were less than the MCID for DLQI and the clinically meaningful difference for HiSQoL [19]. The mean change from baseline in DLQI score was numerically greater in risankizumab treatment groups (180 mg and 360 mg) than in the placebo group [20]. A similar proportion of patients in each group including placebo (5.1%, 7.9%, 7.4%) achieved a DLQI total score of 0 or 1 at Week 16 [20]. Among patients receiving povorcitinib 15 mg, 45 mg, and 75 mg or placebo, 35.0%, 51.3%, 63.2%, and 34.2%, respectively, achieved a reduction in DLQI score greater than the MCID by Week 16 [21]. However, none of the groups reached the clinically meaningful difference for HiSQoL [21]. A DLQI score of 0 or 1 was achieved by two patients (20%) treated with heat shock protein 90 inhibitor RGRN‐305 and none in the placebo group [22].

3.3. Comparative Studies

Modified‐release doxycycline, regular‐release doxycycline, [23] lymecycline, clindamycin plus rifampicin [24, 25] and tetracyclines [25] showed significant QoL improvement and DLQI mean total score changes were higher than the MCID except for tetracyclines [25]. Patients treated with LAight and clindamycin reported significantly better improvement of their QoL than patients treated with clindamycin as monotherapy [26]. DLQI total score changes in patients treated with topical resorcinol 10% exceeded the DLQI MCID. In contrast, patients from the same study treated by clindamycin lotion 1% had minimal QoL improvement and those with no treatment reported worsening of QoL [27]. Adalimumab in conjunction with surgery showed a greater improvement in the mean DLQI total score compared with subjects on adalimumab monotherapy. Mean changes after the treatment were greater than the DLQI MCID in both groups [28]. There was no significant difference between DLQI change in negative pressure wound therapy with or without a split‐thickness skin graft [29] and between thoracodorsal artery perforator flap and muscle‐sparing latissimus dorsi flap [30]. Thoracodorsal artery perforator flap‐based reconstruction led to greater DLQI changes than secondary intention closure after wide local excision. However, the mean DLQI total score changes exceeded the MCID in both groups [31].

Most of the identified clinical trials used the DLQI as an outcome measure and this makes it possible to compare QoL changes between different trials (Figure 2). However, differences in study design, number of study participants, baseline QoL impairment, duration, and comparator groups are potential limiting factors for a direct comparison.

FIGURE 2.

DLQI changes in different clinical trials [32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57].

A retrospective cohort study of 250 patients reported HS flares in 19.2% of patients following vaccination against COVID‐19 and the median DLQI score in patients with flares was significantly higher following vaccination. The authors of that study stated that the mRNA vaccines were associated with a higher risk of HS flare compared to non‐mRNA vaccines [58]. Pain was shown to be one of the largest contributors to impact on QoL in patients with HS. On a 0–10 numeric rating scale, a two‐point increase in HS pain had a similar independent effect on QoL as having Hurley stage III disease compared to Hurley stage I [59]. HS patients with late onset (age ≥ 28 years) reported worse psychosocial QoL compared to early onset (< 28 years). However, no differences in HS clinical severity were observed between the two groups [60]. HS patients with high stigmatization had higher mean DLQI total scores and higher DLQI separate item scores compared to HS patients with low stigmatization [61]. In a study on 96 women with HS, 81% were stigmatized because of HS. Almost 43% reported fear of losing their job because of HS, 34.4% were discriminated against at work and 33.3% stated that HS hindered their career. Sexual impairment was reported by 73.1%. One third of women wanted less or no children because of their HS, 67.7% worried about its impact on pregnancy, birth, and the postpartum period, and 84.6% were worried about the impact of HS treatment on fertility and on their babies health [62].

4. Discussion

Several new HS‐specific QoL instruments have been developed since publication of our previous position paper in 2019 [6]. The process of validation, development of different language versions and severity thresholds for HS‐specific QoL instruments is ongoing. Eligibility criteria for biologics and advanced molecules in HS based on DLQI and HS‐QoL scores were proposed by the European S2k guidelines [4]. In our previous position statement on HS [6] we stated that a DLQI score of 0–1, corresponding to no effect on patient's life according to the DLQI banding descriptions may be considered as a difficult to reach but important treatment goal and since then achievement of this goal has been used as an efficacy criterion in several clinical trials [18, 20]. In randomized, placebo‐controlled studies bimekizumab and heat shock protein 90 inhibitor RGRN‐305 (n = 10) showed QoL improvement slightly above the DLQI MCID [17, 22] Among comparative and open label studies the best improvement of QoL measured by the DLQI was reported after surgical treatment [31, 56].

As previously reported [63] there is still a lack of well‐organized placebo controlled clinical trials with sufficient participant numbers for many treatment methods, in which QoL instruments have been used as outcome measures. Treatable traits in different chronic diseases have been discussed as being important to identify and focus on [64]. Consensus statements and guidelines have agreed on the inclusion of QoL measurement in the assessment of potential treatable traits in HS [3]. We can speculate that the recent increase of research interest in HS may have already caused an improvement in its timely diagnosis and management, possibly leading to improvement in QoL. This may have been a factor in the lower initial DLQI scores in clinical trials over the last 5 years. However, different factors may influence QoL of HS patients. Patients with late onset HS reported worse QoL and higher psychological distress compared to those with early onset HS [60]. Pain, stigmatization and HS‐related fears can have a strong negative impact on QoL in HS [59, 61, 62]. Decrease of stigmatization, pain control and educational work with HS patients may improve their QoL. One study reported more frequent HS flares following vaccination with mRNA vaccines and also worse QoL in those patients [58]. In general, precautionary measures before COVID‐19 vaccination should be taken in a very small subgroup of patients, especially in those with possible severe allergy to ingredients of the vaccine [65] and therefore this issue in HS should be further studied using large databases from different countries.

The DLQI remains a widely used QoL instrument in HS. Its score grading system and MCID are commonly used in clinical trials. Among HS‐specific instruments HSIA, HSQoL‐24, HiSQOL, and QoL‐HS, because of satisfactory validation, manageable number of items, and short recall periods, can be used as outcome measures for assessment of treatment efficacy in HS. HiSQOL‐mini, which consists of a subset of four questions from HiSQOL, is under development and could be well‐suited to routine clinical practice [66]. Available score grading systems for HiSQOL and HSQoL‐24 and clinically meaningful difference for HiSQOL are additional advantages of these instruments [15, 16]. Some aspects of disease‐specific QoL may vary between countries [67] that potentially may lead to cross‐cultural inequivalence of the results. Simultaneous development and validation of QoL instruments in different countries, such as in the development of the Quality of Life Relevance‐Acne and the Infants and Toddlers Dermatology Quality of Life, may improve cross‐cultural equivalence of new instruments [68, 69, 70, 71, 72]. More detailed information on QoL in skin diseases are presented in other publications of the EADV TF on QoL and Patient Oriented Outcomes [73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93].

In conclusion, the contributing EADV TFs recommend that QoL should be assessed in HS. For this, dermatology‐specific and HS‐specific instruments may be used alongside each other. The DLQI is the most widely used QoL instrument in HS. Clinical recommendations and treatment efficacy are based on its score grading system and MCID. The HS‐specific QoL instruments HSIA, HSQoL‐24, HiSQOL, and QoL‐HS have a satisfactory number of items for routine clinical use and short recall periods. HiSQOL and HSQoL‐24 have score grading systems. The MCID for HiSQOL has been calculated. While focusing on the achievement of MCID as a minimal treatment goal, we consider that a QoL score corresponding to no effect on patient's QoL is difficult to reach but an ultimate goal of HS management.

Funding

The authors have nothing to report.

Conflicts of Interest

G. J. had grants or contracts to the institution from Abbvie, Novartis, Union Therapeutics, Henlez, UCB, Incyte and Moonlake and to him personally from Novartis, Union Therapeutics, Henlez and UCB; royalties or licenses both to the institution and to him personally for HISQOL; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events and support for attending meetings and/or travel from UCB; Editor‐in‐chief of Dermatology, vice president EHSF, director GHiSA. Cardiff University receives royalties from some use of the DLQI: A. Y. F receives a share of these under standard university policy (not related to current manuscript). J. R. I received a stipend as immediate past‐Editor‐in‐Chief of the British Journal of Dermatology and an authorship honorarium from UpToDate. He is a consultant for Abbvie, Bluefin, Boehringer Ingelheim, Cantargia, ChemoCentryx, Citryll, Elasmogen, Engitix, Incyte, Indero, InflaRx, Insmed, Kymera Therapeutics, MoonLake, Novartis, Sun Pharmaceuticals, UCB Pharma, UNION Therapeutics, and Viela Bio. He is co‐copyright holder of HiSQOL, HIDE, Investigator Global Assessment and Patient Global Assessment instruments for HS and his department receives income from copyright of the Dermatology Life Quality Index (DLQI) and related instruments. J. S received consulting fees from Leo Pharma, Novartis, Pfizer, Sanofi‐Genzyme, UCB and Galderma; honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from AbbVie, Almirall, Janssen‐Cilag, Eli‐Lilly, Leo Pharma, Novartis, Pfizer, Sanofi‐Genzyme; support for attending meetings and/or travel from Novartis, Sanofi‐Genzyme, Leo Pharma, UCB, Celtrion; President of the Polish Dermatological Society; investigator for AbbVie, Almirall, Amgen, AnaptysBio, BMS, Boehringer Ingelheim, Celtrion, Galderma, Galapagos, Helm AG, Kliniksa, Incyte, InfraRX, Janssen‐Cilag, Leo Pharma, Medimmune, Menlo Therapeutics, Merck, Novartis, Pfizer, Regeneron, UCB, Teva, Trevi. U. G received honorarium for lectures for Hidradenitis suppurativa from Lilly, Sanofi‐Aventis and UCB Pharma and Almirall sponsored participation at EADV congress Paris 2025. M. A has received research grants from Almirall, Biersdorf, GSK and Galderma, LEO, L'Oreal, Pierre Fabre, Roche Posay and Viatris; has served as a consultant or speaker for Almirall, Biersdorf, GSK and Galderma, LEO, L'Oreal, Pierre Fabre, Roche Posay and Viatris; served as a consultant or paid speaker for clinical trials sponsored by companies that manufacture drugs used for the treatment of acne inversa including Almirall, Biersdorf, GSK and Galderma, LEO, L'Oreal, Pierre Fabre, Roche Posay and Viatris. A. M. L received payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from UCB, Novartis and ABBVIE, support for attending meetings and/or travel and Participation on a Data Safety Monitoring Board or Advisory Board from UCB and Novartis. A. B had royalties from Wiley, ad hoc consultancy and lecturing fees from AbbVie, Almirall, BMS, Eli Lilly, Galderma, Incyte, Leo‐Pharma, Janssen, Novartis, Pfizer, Sanofi and UCB, support for attending BAD, EADV and AAD congresses from Novartis, Galderma, UCB, Janssen and Sanofi, immediate Past President of ESDaP, Medical Advisory Board member of the National Eczema Society, Ichthyosis Support Group and Psoriasis Association. M. J. B is a member of Malta Medical Council, President of the Malta Eczema Society, Vice‐President of the Maltese Association of Dermatology and Venereology. C. C. Z has received disease relevant honoraria as a consultant for Almirall, Boehringer Ingelheim, Eli Lilly and Company, Idorsia, MSD, Novartis, Pfizer, PPM, Sanofi, Takeda, UCB and ZuraBio and lecture honoraria from BMS, Novartis and UCB. He is President of the EHSF e. V. President of the Deutsches Register Morbus Adamantiades‐Behçet e. V. Board member of the International Society for Behçet's Disease, coordinator of the ALLOCATE Skin group of the ERN Skin, and chair of the ARHS Task Force group of the EADV. He is Editor of the EADV News, and co‐copyright holder of IHS4 on behalf of the EHSF e. V. Other authors reported no conflicts of interest related to this publication.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.