Hidradenitis suppurativa: One step forward in timely diagnosis and appropriate treatment

Georgios Nikolakis

Thrasyvoulos Tzellos

Hidradenitis suppurativa (HS) is a chronic skin disease with systemic inflammation, which is characterized by painful, deeply seated lesions in the folds of the body.¹ In contrast to psoriasis and atopic dermatitis, disease progression and delay of diagnosis are highly likely to result in a non-reversible phenotype with fistulation and scaring components. The development of sinus tracts and hypertrophic scars signals that the ‘window of opportunity’ for maximum effect of anti-inflammatory treatment may be lost² and that complex treatments are required to efficiently treat such patients.² Historically, the diagnostic delay in HS in an older report of 2020 was documented to be 10.0 ± 9.6 years,³ with patients having to consult on average more than three physicians before being diagnosed with HS. This wandering results in a formidable socioeconomic burden, leading to increased number of surgical procedures, as well as development or progression of certain comorbidities, such as arthritis and inflammatory bowel disease. Moreover, older studies in USA highlight inpatient treatment as the most significant cost factor, covering for 37.4% of all costs⁴ and more frequent emergency department visits and hospitalizations in comparison to psoriasis patients (ratio: 3.2:1).⁵ The study of Sholji et al.⁶ revealed that less than 3% of patients with HS were treated with biologics, while only 17% of patients with pilonidal sinus disease underwent surgery over a 10-year period. These data confirm the deleterious consequences of patient wandering with hallmark being the overall poor access to indicated evidence-based treatment at an early time point, when anti-inflammatory treatment may prevent or even revert disease progression.

The French study of Fite et al.⁷ attempted to capture the patient's wandering to diagnosis after collecting the results from questionnaires distributed to HS patients from 26 French centers in 2024. Interestingly, diagnostic wandering was reported in two thirds of the cases and the average diagnostic delay was estimated to 4.5 years for women and 4.1 years of men. This highlights an overall formidable improvement in timely diagnosis for HS with a significant decrease in average duration over 50% in comparison to the initial reports. This is a very important documented first step in the right direction and can have multiple interpretations. The recent understanding of the pathophysiology of the disease over the last 5 years led to further breakthroughs and two further biologics targeting the cytokines IL-17A (secukinumab) and IL17A/F (bimekizumab) were approved for the treatment of moderate to severe disease. The crucial role of the pharmaceutical industry is not limited to developing specific compounds blocking key inflammatory pathways of the disease but also and most importantly to raising awareness in a multidisciplinary level to increase the chances of reducing diagnostic delay independently of the discipline that has the first contact with the patient. The small but significant difference between females and males raises the question if such awareness campaigns reach certain disciplines more than others and is valuable for strategic modifications of awareness campaign designs for physicians and the industry or patient organizations.

The evolution of HS treatment landscape gives hope to HS patients and physicians for a significant impact on the modification of the disease. An early intervention has the ideal target to reduce inflammation and hinder disease progression. Phase III trials for secukinumab and bimekizumab demonstrate that effective medical treatment of draining tunnels, an unmet need for HS, is becoming more plausible, with inhibition of IL17 being more effective to achieve this goal.⁸ The use of the validated IHS4 classification in order to capture non-mild disease should be promoted, since this score has been shown to serve the capturing of ‘window of opportunity’ need and can lead to early detection of moderate and severe cases, before progression to fistulation.⁹ The use of current validated scoring systems, such as the IHS4⁹ (both the continuous and its dichotomous variant, the IHS4-55¹⁰), allowed the scientific community to shift the focus in the importance of draining tunnels for disease severity and patient burden and serves the effort to correctly assess the effect that new compounds may have in reducing fistulation and achieving higher anti-inflammatory efficacy. Measuring the impact of draining tunnels in a dynamic manner underlines the importance of such lesions in comparison to others, which are subject to continuous fluctuation, such as inflammatory nodules.

A genotype-based definition of rapid disease progressors will allow a more specific and targeted treatment in order to prevent disease progression during the window of opportunity and avoid the ‘hidradenitis suppurativa march’. Defining the HS candidates, for whom a ‘hit hard and early’ therapeutic approach is necessary, will facilitate prevention of disease progression as early as possible thus reducing the socioeconomic burden of the disease for the patients and health care systems.

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Georgios Nikolakis has received honoraria and travel grants from UCB, Novartis, Almirall, BMS, Abbvie, Elli Lilly and his institution received honoraria from Mölnlycke GmbH for his participation in advisory boards. Thrasyvoulos Tzellos has received honoraria from UCB, Novartis, Almirall, BMS, Abbvie, MSD.

Not applicable.