Flare-ups: New Insights into the Burden of Pain in Hidradenitis Suppurativa

To the Editor,

Hidradenitis suppurativa (HS), also termed acne inversa, is a chronic, recurrent, and painful inflammatory skin condition that significantly affects patients’ quality of life (1). Pain is one of the central symptoms contributing to the burden of this disease (2). Krajewski et al. provided valuable insights into this burden through a cross-sectional study involving 1,795 patients (3). The study reported a mean pain level of 3.9 ± 2.9 points within the past 24 h among HS subjects, as assessed using a numerical rating scale (0 = no pain, 10 = worst imaginable pain).

Hidradenitis suppurativa is a disease characterized by periodic exacerbations, i.e., flares (4). More than 80% of patients report experiencing such flares at least monthly (5). Acute flares and the associated pain have a significantly negative impact on the quality of life of HS patients, as demonstrated in a study by Orenstein et al. (6).

While information concerning overall pain levels is available, little is known about HS-flare specific pain. Therefore, we here assess pain levels reported by patients during their last acute flare, aiming to gain new insights into the burden of flare-associated pain in HS (7).

A questionnaire-based study was conducted between February and December 2024 at the HS specialty clinic of the Department of Dermatology, Venereology, and Allergy at the Medical University of Innsbruck, Austria. A total of 66 HS patients (20 women and 46 men) with a median age of 40.5 years (IQR 33.5–52.0) were included in this study. The mean BMI was 30.20 ± 5.87. Notably, 74.6 % of patients were active nicotine users (Table SI). HS severity was assessed using the Hurley staging system and the International Hidradenitis Suppurativa Severity Score System (IHS4). On a numerical rating scale (NRS) (1 = no pain, 10 = worst imaginable pain), patients reported an average pain level of 2.50 ± 2.08 at visit. In response to the question regarding pain during their last acute episode, patients reported an average pain level of 7.60 ± 1.99 NRS (Table I). A total of 56.1% of patients reported a pain level of ≥ 8 NRS and 24.2 % a pain level of 10 NRS (worst imaginable pain). No correlation was found between the Hurley stage or IHS4 score and the intensity of pain experienced during the last acute flare.

Table I.

Results of the Pain Assessment Questionnaire in hidradenitis suppurativa patients

Pain at visit, (1–10 NRS), mean ± SD	2.50 ± 2.08
Pain during last acute episode, (1–10 NRS), mean ± SD	7.60 ± 1.99
Pain level during episode ≥ 8 NRS, n (%)	37 (56,06)
Pain level during episode 10 NRS, n (%)	16 (24,24)

NRS: Numeric Rating Scale; SD: standard deviation.

To the best of our knowledge, this is the first study to quantify flare-specific pain in hidradenitis suppurativa (HS) using a numerical rating scale (NRS). Our findings demonstrate substantial mean pain levels (NRS > 7), with nearly a quarter of patients reporting “worst imaginable pain” (NRS 10) during flares. This underscores the significant burden of flares, particularly given that over 80% of patients experience such episodes at least monthly (5). This underscores the critical importance of reducing flare frequency and implementing adequate pain management strategies in the treatment of HS (8). These results align with Orenstein et al., who identified acute painful flares as the greatest contributor to quality-of-life impairments in 21 HS patients (6).

The absence of a correlation between pain levels and disease severity, as measured by the Hurley and IHS4 scores, suggests that acute flares are perceived as significantly painful events by all HS patients, regardless of clinical severity. Thus, physicians should carefully assess pain in HS, irrespective of numerical disease stage, and provide patients with a comprehensive and multimodal pain management plan.

A limitation of this work is the small sample size. Furthermore, the reliance on patient self-reported outcomes of the last acute episode introduces potential bias, highlighting the need for further research to confirm and expand upon these findings.

We suggest utilizing the recently published guidelines by Surapaneni et al. for the management of acute and flare-associated pain in HS (2). These guidelines provide a comprehensive, patient-centered approach to managing pain during flares. Given that over 50 % of our patients reported pain levels of ≥ 8 NRS, such severe pain presents a significant clinical challenge that demands appropriate therapeutic strategies like immediate release opioids (2). The guidelines by Surapaneni et al. offer an effective roadmap for HS clinicians to address this pressing issue (2). Adopting such a treatment strategy not only improves the quality of life for HS patients, but may also reduce emergency department visits and decrease unsafe self-management practices (2, 6).