Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease that causes painful, recurring lumps, abscesses, and tunnels under the skin, most often in areas where skin rubs together like the armpits, groin, buttocks, and under the breasts. It is not caused by poor hygiene, and it is not a simple infection. The condition stems from a problem in the hair follicles and the immune system’s response when those follicles become blocked and rupture. Despite affecting an estimated one to four percent of the population worldwide, HS remains widely underdiagnosed and undertreated, with many people living with it for a decade before receiving a correct diagnosis.
What Goes Wrong in the Skin
The chain of events that produces HS starts in the hair follicle. The follicle becomes plugged with dead skin cells and debris, a process called follicular occlusion. As the plug builds, the follicle swells and eventually ruptures beneath the skin’s surface. When that happens, the contents of the follicle spill into the surrounding tissue, and the immune system treats it like a foreign invader. This triggers a fierce inflammatory reaction that produces the painful nodules, abscesses, and eventually the sinus tracts (tunnels connecting lesions under the skin) that characterize more advanced disease.1PubMed. Pathophysiology of hidradenitis suppurativa: An update
The immune response in HS skin is not a normal wound-healing reaction. Research comparing HS lesions to healthy skin has found that genes regulated by TNF-α (a key inflammatory signaling molecule) are the most dramatically increased, along with those driven by other inflammatory messengers like IFN-γ and IL-1β. At the same time, molecules that normally dial the immune system down are relatively lacking.2The Journal of Clinical Investigation. Immunopathogenesis of hidradenitis suppurativa and response to anti–TNF-α therapy Studies have also found a pronounced skewing toward a particular type of inflammatory immune cell profile in HS skin, with high levels of IL-17 and other pro-inflammatory signals.3PubMed. Hidradenitis Suppurativa Is Characterized by Dysregulation of the Th17:Treg Cell Axis, Which Is Corrected by Anti-TNF Therapy In practical terms, HS skin is stuck in a state of runaway inflammation that the body’s own braking mechanisms cannot control.
The skin’s microbial community also plays a role. In HS-affected areas, the normal balance of bacteria shifts: beneficial commensal bacteria like Cutibacterium decrease, while opportunistic anaerobic bacteria such as Porphyromonas, Peptoniphilus, and Prevotella become more abundant.4PubMed Central. Microbiome in Hidradenitis Suppurativa-What We Know and Where We Are Heading One study found that Cutibacterium made up nearly 19% of bacteria on normal skin but only about 1% on HS skin.5Journal of Investigative Dermatology. Loss of Skin Microbial Diversity and Alteration of Bacterial Metabolic Function in Hidradenitis Suppurativa Whether this microbial disruption is a cause or a consequence of the disease is still being worked out, but it likely fuels the inflammatory cycle once disease is established.
Genetics and Risk Factors
HS tends to run in families, and about a third of people with the condition report having a relative who also has it. A small but well-characterized subset of familial HS cases has been traced to mutations in the γ-secretase protein complex, which is involved in processing various signaling molecules inside cells. Mutations in components of this complex, particularly NCSTN, PSENEN, and PSEN1, have been found in inherited forms of the disease.6PubMed Central. Insights from γ-Secretase: Functional Genetics of Hidradenitis Suppurativa7JAMA Dermatology. γ-Secretase Mutation in an African American Family With Hidradenitis Suppurativa However, these mutations account for only a minority of all HS cases. For most people, the genetic picture is complex, involving multiple genes that each nudge risk upward without guaranteeing the disease will develop.
Among modifiable risk factors, smoking and obesity stand out. A systematic review and meta-analysis of observational studies found that active smoking was associated with more than four times the odds of HS compared to nonsmokers, and a history of smoking raised the odds even further. Obesity was associated with roughly three-and-a-half times the odds, and metabolic syndrome about twice the odds.8British Journal of Dermatology. Cardiovascular disease risk factors in patients with hidradenitis suppurativa: a systematic review and meta‐analysis of observational studies Both smoking and excess weight promote systemic inflammation, and excess weight specifically increases friction and moisture in skin folds where HS commonly appears. The links between HS and metabolic problems like diabetes and abnormal cholesterol levels hold true even in younger patients and those with mild disease.9PubMed. Hidradenitis suppurativa and the metabolic syndrome
What HS Looks and Feels Like
The disease typically begins after puberty, often in the late teens or twenties, and affects women somewhat more often than men. Early on, it can look like deep, painful pimples or boils that appear in the same areas repeatedly. These are inflammatory nodules and abscesses that form under the skin rather than on the surface. They can be excruciatingly tender, and when they drain they often produce foul-smelling pus. Over time, without adequate treatment, recurring inflammation in the same spots can create sinus tracts, tunnels that connect separate lesions beneath the skin, and thick scarring that distorts the affected area.
Doctors classify HS severity using the Hurley staging system. Stage I involves isolated abscesses without scarring or sinus tracts. Stage II features recurrent abscesses with sinus tracts and scarring in one or more limited areas. Stage III is the most severe, with widespread, interconnected tracts and scarring across entire regions. A refined version of this system subdivides stages I and II into mild, moderate, and severe substages to help guide treatment decisions.10British Journal of Dermatology. Correlation of the refined Hurley classification for hidradenitis suppurativa with patient‐reported quality of life and objective disease severity assessment More recently, ultra-high frequency ultrasound has shown promise in detecting hidden tunnels and subclinical lesions that are invisible to the naked eye, sometimes leading to patients being reclassified at a higher severity than their clinical exam suggested.11PubMed. Enhancing Hidradenitis Suppurativa Assessment: The Role of Ultra-High Frequency Ultrasound in Detecting Microtunnels and Refining Disease Staging
Why Diagnosis Takes So Long
One of the most frustrating aspects of HS is how long it can take to get a proper diagnosis. A study examining diagnostic delay found that people waited an average of ten years between their first symptoms and receiving a diagnosis. During that time, patients saw more than three different doctors on average and received more than three incorrect diagnoses.12PubMed Central. Delayed Diagnosis of Hidradenitis Suppurativa and Its Effect on Patients and Healthcare System The most common misdiagnosis is simple abscesses or boils, which were the alternative diagnosis in more than half of cases in one analysis.13PubMed. Diagnostic delay in Hidradenitis suppurativa investigated using data from social media and from statutory health insurances
This matters because early HS is more treatable than advanced disease. When individual flares keep getting lanced and drained as if they are random abscesses, the underlying inflammatory process marches on unchecked, and irreversible scarring and tunneling accumulate. If you keep getting painful lumps in the same body areas, especially the groin, armpits, or under the breasts, and they leave scars or seem to be connected to each other, bring up HS specifically with your doctor. A dermatologist with experience in the condition is the best starting point.
The Psychological and Sexual Health Burden
HS does not stay confined to the skin. Pain is the single strongest driver of reduced quality of life, with disease severity (Hurley stage II and III) and symptoms like itch, anxiety, and depression all independently contributing to how much the condition impairs daily functioning.14PubMed. The Influence of Pain on Reduced Quality of Life in Patients with Hidradenitis Suppurativa: A Single-Center Retrospective Study
Depression and anxiety are strikingly common. A meta-analysis pooling data from multiple studies found that about a quarter of HS patients met criteria for depression compared with roughly 7% of people without HS, translating to about two-and-a-half times the odds. Anxiety followed a similar pattern, present in about 18% of HS patients versus 7% of controls, with double the odds.15PubMed. Association between hidradenitis suppurativa, depression, anxiety, and suicidality: A systematic review and meta-analysis A large population-based study from Denmark found that after adjusting for many potential confounders, people with HS had about 1.7 times the risk of developing a first episode of depression and about 1.5 times the risk of a first anxiety diagnosis compared with matched controls.16JAMA Dermatology. Risk of New-Onset and Recurrent Depression and Anxiety Among Patients With Hidradenitis Suppurativa Suicide risk is also elevated: one analysis estimated the odds of suicidality were roughly twice as high in HS patients compared to the general population.17PubMed Central. Hidradenitis Suppurativa Burdens on Mental Health: A Literature Review of Associated Psychiatric Disorders and Their Pathogenesis
Sexual health takes a direct hit as well, partly because HS lesions commonly affect the groin, inner thighs, and buttocks. A cross-sectional study reported sexual dysfunction in roughly half of women and about 60% of men with HS. Pain, odor from draining lesions, and the presence of active lesions in genital areas were major contributing factors.18PubMed Central. Burden of Hidradenitis Suppurativa: A Systematic Literature Review of Patient Reported Outcomes These are not marginal concerns; they sit at the core of why HS can be so devastating even when the disease occupies a relatively small body surface area.
HS and Other Diseases
The chronic inflammation driving HS does not confine itself neatly to the skin. The same meta-analysis that documented cardiovascular risk factors in HS found elevated rates of diabetes, abnormal lipid levels, and metabolic syndrome across the HS population.8British Journal of Dermatology. Cardiovascular disease risk factors in patients with hidradenitis suppurativa: a systematic review and meta‐analysis of observational studies This means that screening for heart disease risk factors deserves a place in routine HS care, even for younger patients.
Crohn’s disease, the inflammatory bowel condition that causes ulcerations and tunneling in the gut, shares striking parallels with HS. Both diseases produce sinus tracts and granulomatous inflammation, overlap in certain genetic susceptibility loci, involve similar immune signaling pathways, and respond to some of the same medications.19PubMed Central. Association of hidradenitis suppurativa with Crohn’s disease A large cross-sectional study found a significant association between HS and Crohn’s disease specifically, but not with ulcerative colitis (the other major form of inflammatory bowel disease), supporting the idea that the two conditions share a particular immunologic pathway rather than reflecting general inflammatory bowel disease risk.20PubMed. The Association between Hidradenitis Suppurativa and Crohn’s Disease: in Search of the Missing Pathogenic Link
Antibiotics and Hormonal Therapy
For mild to moderate HS, antibiotics remain a first-line treatment, though the goal is to reduce inflammation rather than to eradicate a specific bacterial infection. The most commonly used oral regimen is a combination of clindamycin and rifampicin, typically given for ten weeks. In a European prospective cohort, this combination and tetracycline antibiotics both produced significant decreases in disease severity scores, with clinical response rates in the range of 40 to 48%.21PubMed. The efficacy and tolerability of tetracyclines and clindamycin plus rifampicin for the treatment of hidradenitis suppurativa: Results of a prospective European cohort study A smaller study from Singapore reported that roughly two-thirds of patients on clindamycin-rifampicin saw clinical improvement after ten weeks.22PubMed Central. The effect of oral clindamycin and rifampicin combination therapy in patients with hidradenitis suppurativa in Singapore Antibiotics can help control flares, but they are not a long-term solution for most patients, and repeated courses risk antibiotic resistance and gut disruption.
For women, the anti-androgen medication spironolactone has emerged as a useful option. One study found that patients on spironolactone achieved significant improvement in pain, inflammatory lesion counts, and overall disease severity, though it did not reverse existing scarring or fistulas.23PubMed. Antiandrogen therapy with spironolactone for the treatment of hidradenitis suppurativa A retrospective analysis found the medication was less effective for the most advanced disease: patients at Hurley stage III were 85% less likely to improve on spironolactone compared to those with milder disease.24PubMed Central. Efficacy of spironolactone in treating hidradenitis suppurativa in women of childbearing age: a single-center retrospective analysis Since spironolactone can cause birth defects, effective contraception is necessary for anyone who could become pregnant.
Biologic Medications
When antibiotics are insufficient, biologic drugs represent the next major step. Currently, three biologics are approved for HS: adalimumab (a TNF-α blocker), secukinumab (an IL-17A blocker), and bimekizumab (which blocks both IL-17A and IL-17F).25PubMed. Biologic therapies and small molecules in the treatment of hidradenitis suppurativa All three are considered moderately effective, and achieving full disease control remains challenging for many patients.
Adalimumab was the first biologic approved for HS and has the longest track record. However, real-world data tell a sobering story about durability: in a daily-practice cohort, only about 56% of patients were still on adalimumab at one year, and that figure dropped to roughly 31% at two years, mostly because it stopped working well enough. Infliximab, another TNF-α blocker used off-label, had somewhat better staying power at about 49% at two years.26British Journal of Dermatology. Adalimumab and infliximab survival in patients with hidradenitis suppurativa: a daily practice cohort study A head-to-head comparison of the two found that infliximab outperformed adalimumab across severity measures in patients with severe disease.27PubMed. Comparing treatment outcome of infliximab and adalimumab in patients with severe hidradenitis suppurativa
The newer IL-17 blockers target a different piece of the inflammatory cascade. Secukinumab and bimekizumab both received approval more recently. Because bimekizumab blocks two forms of IL-17 instead of just one, there is a theoretical case for broader inflammation control, but no head-to-head trials between the two drugs have been conducted yet, and the published real-world evidence for bimekizumab is still thin.28Actas Dermo-Sifiliográficas. Real World Evidence of Secukinumab and Bimekizumab in Hidradenitis Suppurativa: A Systematic Review and Meta-Analysis For now, the choice between biologics often depends on insurance coverage, prior treatment history, and individual response.
Surgery and Laser Treatment
Medications can reduce inflammation and the frequency of flares, but they cannot remove existing sinus tracts and scar tissue. That is where surgery comes in. Several approaches exist, and the recurrence rates differ meaningfully. A meta-analysis found that wide excision, which removes the entire affected skin area with a margin of healthy tissue, had the lowest average recurrence rate at about 13%. Local incision (cutting out individual lesions) recurred in about 22% of cases, and deroofing (removing only the roof of a sinus tract) in about 27%.29PubMed. Recurrence of hidradenitis suppurativa after surgical management: A systematic review and meta-analysis Wide excision is the most definitive but also involves the longest recovery and the largest wound, sometimes requiring skin grafts or flap reconstruction. Deroofing is less invasive and heals more quickly, making it a reasonable option for individual troublesome tracts even though it carries a somewhat higher recurrence rate.
Long-pulsed Nd:YAG laser therapy offers a non-surgical approach that targets hair follicles with light energy, reducing the number of follicles that can become blocked in the first place. In a randomized controlled trial, treated sites showed about a 65% reduction in disease severity after three months of monthly sessions, while untreated control sites on the same patients showed no significant change.30PubMed. Randomized control trial for the treatment of hidradenitis suppurativa with a neodymium-doped yttrium aluminium garnet laser A separate prospective study reported about 73% improvement on the laser-treated side versus about 23% on the control side after four months of treatment.31PubMed. Prospective controlled clinical and histopathologic study of hidradenitis suppurativa treated with the long-pulsed neodymium:yttrium-aluminium-garnet laser Laser therapy is best suited for mild to moderate disease and works particularly well as an adjunct to medical treatment rather than a standalone solution for advanced cases.
Lifestyle and Self-Management
Quitting smoking is one of the most impactful things a person with HS can do. A large cohort study found that people who quit smoking had about a 32% lower risk of developing HS compared to those who continued, and the benefit was comparable to that seen in people who had never smoked. People who quit but then started again returned to the same risk level as continuous smokers.32JAMA Dermatology. Smoking Cessation and Risk of Hidradenitis Suppurativa Development In a survey of HS patients who made lifestyle changes, about 28% had eliminated smoking, and roughly 31% reported their HS became “much better” as a result.33Dermatology. Prevalence and Impact of Dietary Avoidance among Individuals with Hidradenitis Suppurativa
Dietary changes are more speculative but widely discussed among patients. Some reports suggest that avoiding brewer’s yeast, reducing refined carbohydrates and dairy, and following anti-inflammatory eating patterns may help certain individuals.34Undergraduate Research in Natural and Clinical Science and Technology. Hidradenitis Suppurativa: Causes, Symptoms, and Treatment The evidence base for specific diets is still weak, consisting mostly of small studies and patient surveys rather than controlled trials. That said, losing weight if you carry excess weight has a clear physiological rationale: less skin-fold friction, reduced systemic inflammation, and improved metabolic health. Wearing loose-fitting, breathable clothing and using gentle antiseptic washes on affected areas are common practical recommendations from dermatologists, though large trials on these measures are lacking.
Racial Disparities in HS Care
HS does not affect all populations equally, and neither does its treatment. A single-institution analysis of nearly 2,000 HS cases found that African American patients more commonly had HS in the armpits, buttocks, breasts, abdomen, and thighs compared to non-African American patients. African American patients were also more likely to receive only medical management, while non-African American patients were more likely to undergo surgery.35PubMed Central. Racial Disparities in Hidradenitis Suppurativa Management at a Single Institution The reasons behind these treatment disparities are likely multifactorial, involving differences in access to specialists, insurance coverage, provider bias, and referral patterns. For a disease that often requires surgical intervention to manage sinus tracts and scarring, inequitable access to surgery translates to worse long-term outcomes.
Drugs in the Pipeline
The fact that existing treatments leave many patients with inadequate control has spurred a wave of clinical trials targeting new parts of the immune system. JAK inhibitors, a class of oral medications that interfere with intracellular inflammatory signaling, are the most advanced candidates. Povorcitinib, a JAK1 inhibitor, produced statistically significant reductions in inflammatory nodule and abscess counts at all three tested doses compared to placebo in a phase 2 trial, with clinical response rates of roughly 44 to 48% versus 29% for placebo.36Journal of the American Academy of Dermatology. Efficacy and safety of povorcitinib, an oral Janus kinase 1 inhibitor, in patients with hidradenitis suppurativa: A phase 2, randomized, double-blind, placebo-controlled study
A separate phase 2 trial tested three different drugs simultaneously: brepocitinib (a JAK1/TYK2 inhibitor), zimlovisertib (an IRAK4 inhibitor), and ropsacitinib (a TYK2 inhibitor). Brepocitinib was the winner, with about 52% of patients achieving clinical response at 16 weeks compared to 33% on placebo. The other two drugs did not meaningfully separate from placebo, suggesting that the broader JAK pathway is a more productive target than selective IRAK4 or TYK2 inhibition alone.37PubMed. Brepocitinib, Zimlovisertib, and Ropsacitinib in Hidradenitis Suppurativa Upadacitinib, a JAK1 inhibitor already approved for other inflammatory conditions, is also being studied in HS, though published data so far are limited to a small real-world series.38PubMed Central. Hidradenitis Suppurativa and JAK Inhibitors: A Review of the Published Literature If the larger phase 3 trials currently underway confirm these early signals, oral JAK inhibitors could become an important addition to the treatment landscape within the next few years, offering an alternative to injectable biologics that some patients find burdensome.