Understanding Moderate Hidradenitis Suppurativa: Diagnosis, Impact, and Treatment

In a recent Dermatology Times Partner Perspectives video series, “Understanding Moderate Hidradenitis Suppurativa: Diagnosis, Impact, and Treatment,” Martina Porter, MD, dermatologist and the vice chair of research at Beth Israel Deaconess Medical Center, and Amit Garg, MD, professor and chair for the Department of Dermatology at Northwell Health, shared insights into the diagnosis, psychosocial impact, and evolving treatment strategies for patients with moderate hidradenitis suppurativa (HS). The discussion highlighted the need for earlier recognition, standardized assessment, and timely initiation of systemic therapies to improve outcomes and quality of life for patients living with this complex disease.

HS is a chronic inflammatory disorder primarily affecting apocrine gland–bearing skin, most commonly the axillae and groin.^1,2 “It is a progressive disease,” shared Dr Porter, characterized by inflammatory nodules, abscesses, and draining tunnels.^3-5 The disease affects an estimated 0.1% to 1% of the population, typically emerging in young adulthood.^3,6-8

“The pathophysiology of HS is not fully known,” Dr Porter explained, “but our current knowledge of its mechanisms is key toward understanding how the disease progresses.” Cytokines such as TNF-alpha and IL-17 play central roles in driving inflammation.⁹ Elevated levels of these cytokines correlate with disease severity, supporting their role as therapeutic targets.⁹ Bacterial biofilms are also commonly detected in HS lesions, further contributing to chronic inflammation and treatment resistance.¹⁰

The disease is heterogeneous.¹¹ Dr Porter shared that patients often present with varying lesion types, levels of pain, and disease activity that waxes and wanes.^1,12 This variability complicates staging and management, with patients frequently going undiagnosed or misdiagnosed for years. According to Dr Porter, “On average, patients exhibit symptoms for 7 to 10 years before the disease is accurately diagnosed.”^1,7,13

Clinicians often rely on Hurley staging, a widely used but static system that classifies HS severity based on the presence of abscesses, sinus tracts, tunnels, and scarring.³ “According to this framework,” Dr Porter explained, “stage 1 reflects ‘mild’ patients that are characterized by single or multiple abscess formation without tunneling and scar formation; stage 2 or ‘moderate’ patients are defined by recurrent abscesses with tunnels, scarring, and a single lesion or multiple widely separated lesions; and stage 3 or ‘severe’ patients exhibit diffuse or near diffuse involvement or multiple interconnected tunnels and abscesses across entire areas.”^3,14

According to Dr Porter, there are, however, some limitations of the Hurley scoring system, as Hurley scoring addresses the extent of involvement of an anatomic region but does not specifically assess the inflammatory symptoms.¹⁵ 

Helping to better define the moderate patient, the International Hidradenitis Suppurativa Severity Score System (IHS4) was developed as a dynamic tool that quantifies inflammatory activity.^15,16 It assigns weighted scores to nodules (×1), abscesses (×2), and draining tunnels (×4). Dr Porter explained, “A score of 4 to 10 reflects moderate disease, often characterized by multiple painful nodules, occasional abscesses, and early tunnel formation.”¹⁵

Dr Porter shared that clinical trials can further describe the moderate patient, typically requiring a total of at least 5 inflammatory lesions (ie, abscesses and/or inflammatory nodules), with lesions affecting at least 2 distinct anatomic areas. These inclusion criteria help capture the true burden of moderate disease and ensure reproducibility in research settings.^17-19

Beyond physical symptoms, HS has a psychosocial impact that can greatly affect patients. Even in moderate disease, patients experience disproportionately high rates of mental health challenges. According to Dr Porter, 28.6% of patients report depressive symptoms, 57.5% of patients report anxiety, and 42.8% of patients experience sleep disruption.^7,20

Body image and self-confidence are also deeply affected. Over 56% of patients choose clothing to conceal lesions,⁷ while pain, embarrassment, and drainage can interfere with intimacy and strain personal relationships.²⁰

Work productivity is also impaired, with nearly 30% of moderate patients reporting employment difficulties.²¹

“A recent meta-analysis found that patients with HS were at an increased risk of completed suicide compared with the general population,” said Dr Porter. “Although data on suicide and skin disease in general are limited, the available evidence of this association reinforces the broader notion that HS has a powerful psychosocial impact on patients.”²²

Dr Porter explained that a majority of mild-to-moderate HS patients report that HS affects their quality of life to some degree and that this impact can be devastating regardless of severity.²¹ Because the burden of HS is quite high, there is a greater impact on a patient’s health-related quality of life than other high-burden skin diseases. A recent study showed that reported quality-of-life measures were worse in HS studies than in studies of alopecia, acne, psoriasis, urticaria, and atopic dermatitis.²³

“These statistics are very impactful to me as a physician,” explained Dr Porter. “While it is evident that even mild-to-moderate disease can have a significant impact on the patient, it is important to recognize that severe disease has an even greater impact on patients, and therefore diagnosing and treating patients early in the disease course is crucial to improving a patient’s quality of life.”²¹

Diagnostic delays remain one of the greatest barriers to effective HS management, according to Dr Porter. “During this time, many patients see multiple health care providers—81.1% consult at least 3 or more—before HS is identified,” she said.⁷ “This delay is particularly concerning, as 93.3% of patients exhibit moderate or severe disease by the time of diagnosis.¹ In my clinical experience, this trend may be attributed, in part, to the diagnostic challenges associated with milder and intermittent presentations of the disease.”

Dr Porter explained that compounding this issue is the episodic nature of HS: nearly 80% of patients experience flares rather than continuous disease activity, making severity difficult to assess during a single clinic visit. For some, progression from mild-to-moderate disease occurs rapidly; others remain stable for years. “Timely management is crucial in preventing progression to moderate-to-severe stages of HS,” shared Dr Porter.^21,24 

According to Dr Garg, “In my clinical experience, by the time a patient has their first visit with a dermatologist, a patient may have already progressed from mild-to-moderate disease.”¹ He explained that early recognition and referral to a dermatologist, coupled with timely initiation of disease-modifying therapy, are critical for improving outcomes and halting disease progression in patients with HS, particularly for moderate patients.^14,25-27

“These ‘moderate’ patients typically exhibit recurring inflammation with persistent lesion burden that is insufficient to meet criteria for moderate-to-severe disease and yet too extensive to be considered mild,” explained Dr Garg.^17-19,28

An emerging strategy for earlier recognition of moderate HS is the use of ultrasound. While not yet standard in routine practice, ultrasound offers a noninvasive method to aid diagnosis and staging, which may help guide medical management.²⁹

“Ultrasound devices can image subclinical changes in hair follicles, such as curving, widening, and ballooning, which may be early indications of nodule or tunnel formation,” said Dr Garg.²⁹ “The early identification of tunnels is especially important since presence of tunnels is closely associated with moderate disease, disease progression, and worse treatment outcomes.” Imaging can support timely initiation of the most appropriate therapy for moderate disease.^30,31

Management of moderate HS requires an individualized therapeutic approach, particularly in patients with comorbidities, according to Dr Garg. “The common goal for patients with moderate disease includes adequate control of symptoms, slowing disease progression, and minimizing debilitating scarring,” he said.^11,25

Recently approved European guidelines underscore advances in HS care by emphasizing a broad spectrum of therapeutic interventions.¹⁵ Dr Garg explained that the guidelines emphasize classifying HS into inflammatory (active) and noninflammatory (inactive) forms and uses IHS4 classification to stage patients as having mild, moderate, and severe disease.¹⁵

“This division allows for appropriate selection of therapy based on level of inflammatory burden,” said Dr Garg. “Treatment for the inflammatory form focuses predominately on pharmacological treatment, such as oral antibiotics and Health Authority–approved biologics such as adalimumab, secukinumab, and bimekizumab. In contrast, the noninflammatory form emphasizes procedure-based management approaches.”¹⁵

According to the European guidelines, biologic therapy should be initiated in patients with moderate-to-severe or progressive HS, involvement of sensitive anatomical sites (genitals, face, scalp, or neck), or substantial impairment in quality of life. Recommended first-line biologics in these settings include adalimumab, secukinumab, and bimekizumab. Dr Garg shared that these agents are now approved in both the United States and Europe for moderate-to-severe HS, offering patients disease-modifying options that may prevent progression and reduce long-term complications.¹⁵

According to Dr Garg, the UNITE study provided real-world data on health care utilization among patients with HS treated with adalimumab, infliximab, or ustekinumab. “The patients who utilized these biologic therapies for at least 6 months reported fewer HCP visits, ED visits, and hospital admissions than in the same timeframe prior to initiating their biologic,” he said. “Additionally, fewer patients utilized antibiotics after starting biologic therapy.”³²

Despite this, adoption remains limited, explained Dr Garg. Only about 31% of patients with moderate HS have used biologics, in part because 44% of physicians prefer to exhaust other treatments first.³³ “In our clinical experience, early implementation of biologics, prior to the development of severe disease, may prevent further formation of tunnels and scarring,” said Dr Garg.³⁴

Dr Garg explained that evolving treatment strategies in HS emphasize a comprehensive approach that integrates anti-inflammatory medical therapies with procedural interventions to address irreversible tissue damage, thereby tailoring management to disease severity,¹⁵ as well as a multidisciplinary approach that includes “addressing the numerous comorbid conditions that afflict patients with HS.”^15,35

HS is a multifaceted disease that poses significant diagnostic and management challenges. According to Dr Porter and Dr Garg, early diagnosis and intervention at the moderate stage are critical to preventing the progression to severe, debilitating, and irreversible disease outcomes.

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