Hidradenitis suppurativa, commonly abbreviated as HS, is a chronic inflammatory condition that manifests as painful nodules, abscesses, and draining tunnels, known as sinus tracts, primarily in intertriginous areas such as the armpits, groin, and under the breasts. The disease is driven by an immune-mediated inflammatory process centered on the hair follicle and apocrine gland units, and it is now understood to fall within the broader family of immune disorders that includes psoriasis and inflammatory bowel disease. Beyond its physical burden, HS carries a staggering comorbidity load: patients experience elevated rates of metabolic syndrome, cardiovascular disease, depression, and anxiety, and quality-of-life scores for HS patients routinely rank among the lowest of any dermatological condition studied.

For decades, treatment options for HS were limited to antibiotics, hormonal therapies, and surgical interventions, often with modest results. The arrival of biologic therapies—monoclonal antibodies engineered to target specific components of the immune system, most notably tumor necrosis factor-alpha inhibitors such as adalimumab and secukinumab, which blocks the interleukin-17A pathway—transformed the therapeutic landscape. Clinical trials and real-world studies have demonstrated that these agents can dramatically reduce inflammatory nodule counts, halt the formation of new sinus tracts, and in some patients induce near-complete clearance of disease activity. Yet access to these medications remains unevenly distributed across the population, a problem compounded by the drug’s high cost, the need for specialist prescribing, and the frequent requirement for prior authorization from insurance providers.

The new study, led by Sydney A. Barlow of the University of Pittsburgh School of Medicine, together with Christopher A. Guirguis of Georgetown University School of Medicine and Joe K. Tung of the University of Pittsburgh Medical Center, sought to quantify precisely how sociodemographic factors influence biologic access in the adult HS population. While pediatric disparities in biologic use for HS had been documented in prior literature, little was known about whether similar inequities persist into adulthood. Understanding these disparities, the researchers argue, is critical because delayed initiation of appropriate therapy may represent a missed opportunity to prevent disease progression before irreversible tissue damage, scarring, and fistula formation take hold.

To conduct their analysis, the team turned to the All of Us database, one of the largest and most diverse biomedical research repositories in the United States, maintained by the National Institutes of Health. From version 8 of this dataset, they identified 3,308 adults diagnosed with HS. The cohort was, on average, 51.1 years old, predominantly female, largely non-Hispanic/Latino in composition, overwhelmingly insured, and mostly composed of individuals who did not report delayed care due to rural residence. The researchers then employed multivariable regression analysis to assess two distinct outcomes: the odds of ever receiving biologic therapy, and the time elapsed before biologic initiation. The predictor variables included age, gender, race and ethnicity, income, insurance status, rurality, and health literacy, with smoking status controlled across all analyses—a methodologically important decision, given that smoking is both a major risk factor for HS and a potential confounder of treatment decisions. The time-to-treatment arm of the analysis was restricted to the 195 patients who ultimately received biologic therapy, a subset that itself underscores how few adults with HS in the cohort ever reached biologic treatment at all.

The results were striking in their simplicity and their implications. When the researchers examined the odds of receiving biologic therapy, age emerged as the only significant sociodemographic predictor. Specifically, each additional year of age was associated with a 2 percent decrease in the odds of receiving biologics, yielding an odds ratio of 0.98 with a 95 percent confidence interval of 0.97 to 0.99 and a p-value of less than 0.001. In practical terms, this means that a 65-year-old patient with HS would have substantially lower odds of ever being placed on a biologic than an otherwise similar 45-year-old, even after accounting for insurance status, income, and other potentially confounding variables.

The time-to-treatment analysis revealed an even more nuanced picture of inequity. Each additional year of age was associated with a 29-day longer delay in starting biologic therapy, with the regression yielding a beta coefficient of 29.29 and a 95 percent confidence interval of 6.74 to 51.84, at a p-value of 0.01. Gender also proved to be a powerful and independent predictor of treatment timing: female gender was associated with a significantly longer time to biologic initiation compared to males, with a beta coefficient of 1,071.52 and a 95 percent confidence interval spanning 369.11 to 1,773.94, at a p-value of 0.003. The magnitude of this gender effect is remarkable—suggesting a delay on the order of years, not merely months, for women relative to men in the pathway to biologic treatment.

The researchers propose several possible mechanisms to explain these patterns. For older adults, the under-prioritization of biologic therapy may stem from prescribing biases among clinicians, who may perceive older patients as less suitable candidates for immunomodulatory treatment due to concerns about infection risk, malignancy, or polypharmacy interactions. Alternatively, under-recognition of disease severity in older patients may lead clinicians to underestimate the burden of HS and to delay escalation to advanced therapies. There is also the possibility of therapeutic nihilism—a subtle, often unconscious assumption that older patients have “lived with” their disease for so long that aggressive intervention is unnecessary or futile.

The gender-based delay is more difficult to attribute to a single mechanism, but the wider medical literature offers compelling clues. Prior research has documented gender bias and diagnostic delays in young women across a range of conditions, and HS itself presents differently between the sexes: women more frequently exhibit atypical or truncated disease patterns, which may confound clinical assessment and delay recognition of severity. Moreover, a systematic review of sex and gender differences in treatment outcomes for inflammatory skin diseases has called into question whether current dosing and treatment guidelines adequately account for these differences, raising the possibility that clinicians’ uncertainty about biologic efficacy in female patients contributes to more conservative prescribing behavior. Hormonal factors, pregnancy planning considerations, and differences in pain reporting and healthcare-seeking patterns may all contribute as well.

The public health implications of these findings extend well beyond the individual patient. HS is a progressive disease in which early intervention is believed to alter the long-term trajectory, potentially preventing the development of irreversible scarring and functional impairment. Every year of delay in initiating effective therapy represents a window during which inflammation may continue to remodel tissue architecture and entrench disability. For older patients, this means that each additional birthday may bring not only the expected 29-day increase in wait time but also a compounding reduction in the likelihood of ever receiving the therapy at all. For women, the gender-based delay may contribute to a lifetime of avoidable suffering, lost productivity, and diminished quality of life.

The study’s authors emphasize that their findings underscore the need for heightened clinician awareness of age- and gender-related disparities in HS management. Ensuring timely and equitable access to biologic therapies, they argue, is critical to improving outcomes and quality of life for patients with HS. This will likely require not only greater vigilance on the part of dermatologists and primary care providers but also structural reforms to the systems that govern access to expensive specialty medications, including streamlined prior authorization processes, expanded insurance coverage, and more aggressive patient education about available treatment options.

It is worth noting the limitations inherent in the study’s design. As an observational analysis drawing on self-reported and registry-based data from the All of Us program, the findings demonstrate association rather than causation. The relatively small number of patients who ultimately received biologics—just 195 out of more than 3,300—also limits the statistical power available for the time-to-treatment analysis, and the broad confidence intervals around some estimates reflect this constraint. Nevertheless, the consistency of the age effect across both outcomes, and the sheer magnitude of the gender-based delay, lend weight to the conclusion that these are real and consequential patterns rather than statistical noise.

As biologic therapies continue to demonstrate impressive efficacy and improving safety profiles in HS, the question of who gets access to them—and how quickly—becomes increasingly urgent. This study adds its voice to a growing chorus of research suggesting that the answer to that question is not currently determined by disease severity alone, but also by characteristics as incidental as a patient’s age and gender. For a condition as painful, stigmatizing, and life-altering as hidradenitis suppurativa, those are variables that no patient’s treatment timeline should depend upon.