The landmark 23-country study reveals the disease is on par with rheumatoid arthritis in prevalence and can no longer be ignored.
The first standardised global prevalence study on hidradenitis suppurativa has shattered long-held assumptions it is a rare disease.
The startling new evidence reveals that about one in 100 people are affected by the disease – an incidence on par with rheumatoid arthritis.
The Global Hidradenitis Suppurativa Atlas (GHiSA) study confirms HS is not a rare disorder but a common, devastating inflammatory disease that remains largely invisible in health policy, leaving patients to endure years of pain, scarring and stigma before diagnosis or adequate care.
The overall random-effect pooled global prevalence of HS was 0.99% (95% CI, 0.67%-1.46%). In Australia, it was 0.90% (95% CI, 0.47%-1.72%).
“As it pools evidence across continents, this study sends a clear signal to policymakers and health systems that HS is not rare – and deserves far more attention,” said GHiSA general secretary Dr Dorra Bouazzi.
Findings have been published in JAMA Dermatology.
This study marks the first phase of GHiSA’s multi-year program. The second phase will focus on developing globally harmonised diagnostic and reporting criteria, a critical step toward improving epidemiological accuracy and enabling meaningful comparisons across regions.
The third phase will deepen the investigation into phenotype, genotype, environmental exposures, lifestyle factors and comorbidities, with the aim of building evidence-based strategies for prevention, diagnosis and care.
Drawing on clinical examinations of 22,743 participants across 23 countries, the GHiSA study revealed substantial regional variation in prevalence, offering early signals that environmental, genetic or healthcare-system factors may be influencing disease expression.
Despite long-standing assumptions linking HS to lifestyle factors such as obesity and smoking, the study found no consistent associations with BMI, smoking, GDP or the Human Development Index.
The only demographic factor consistently linked to HS was female sex, highlighting an urgent need to understand the biological and structural determinants behind this disparity, the researchers said.
HS is a chronic, non-communicable inflammatory skin disease marked by painful nodules, abscesses and malodorous discharge in intertriginous areas, causing extensive scarring and functional impairment.
Patients often experience profound psychological repercussions, with social withdrawal and stigma contributing to suicide mortality rates more than double those of the general population.
Yet despite this heavy toll, HS remains underdiagnosed and undertreated worldwide, and misconceptions about its prevalence have led to chronic underinvestment in research, workforce capacity and patient support services.
Professor Gregor Jemec, Professor of Dermatology at the University of Copenhagen and GHiSA chair, said it was a unique and important alliance.
“The GHiSA studies are a powerful example of a mutually committed global academic collaboration and should form the foundation of meaningful change in how HS is recognised and ultimately managed worldwide,” he said.
The initiative is supported by extensive collaboration with patient organisations, including GlobalSkin, Patientforeningen HS, EHSF and research partners C3/Historic and HS Progress.
Funded by an International League of Dermatological Societies grant with support from UCB, the project forms a central pillar of the ILDS’ Grand Challenges in Global Skin Health initiative.
ILDS President Professor Henry W. Lim described the study as a critical advance toward reducing the global burden of HS.
“We’re delighted to collaborate with the GHiSA team and congratulate them on the publication of this important study,” he said.
“We hope it proves a turning point in treatment for this distressing disease.”
For health professionals, the implications were massive, said Australian dermatologist and ILDS treasurer Professor Stephen Shumack.
He said the global dermatology community now had the evidence needed to demand stronger health-system responses, greater research investment and a fundamental re-evaluation of how this debilitating disease is addressed worldwide.
And he hopes it will mean much greater strides in earlier diagnosis, awareness and timely access to appropriate treatment for the many Australians who have gone unidentified for too long.
“Hidradenitis suppurativa has certainly been around for a long time and it was always thought to be a relatively rare condition,” he told The Medical Republic.
“Even dermatologists would think we really only have a few cases of it. But what’s happened over the last probably 10 or 15 years, there’s been some new treatments, and these are the treatments that we’re using for psoriasis or rheumatoid arthritis, and these biological agents that actually work.
“They’re not as fabulous as they are in psoriasis, but they’re pretty good. And so what’s happened? A lot of these patients have come out of the woodwork.”
Professor Shumack said one of the main challenges with increasing awareness of diseases like HS was the lack of data.
“With more data like this demonstrates, hopefully, to universities, to industry, to health departments, and policy makers that they need to focus on this quite common condition,” he told TMR.
“It’s 1% of the population that can and often does, have really disastrous issues, psychological issues, social issues, medical issues, with young members of the population, teenagers and people in their 20s most likely to be affected.
“Many of them have probably given up thoughts of having their ideal job. They might have dropped out of university. They might be unable to have social interactions with other people and form relationships. It can be an absolute disaster.
“Let’s say you’ve got a reasonable sized town of 10,000 people. That means about 100 people have got this condition and say half have been significantly impacted with this condition.
“If you can adequately manage those people, diagnose and manage them early on, that’s an extra 50 to 100 people you’re going to get contributing to that town of 10,000 and also have a much better quality of life.”
Professor Shumack said GPs were key to helping identify the disease early. Generally, it’s younger people at first presentation, although some people might delay seeking a diagnosis into their 30s and 40s due to previous misdiagnosis or embarrassment.
“The key really is to get it early, with the teenagers and people in their early 20s,” he said.
“It’s cysts or abscesses or boils in the armpits and the groin area, and it’s more common in females.”
