Hidradenitis suppurativa (HS) is not contagious. You cannot catch it from someone else or pass it to another person through skin contact, sexual contact, or any other form of transmission. HS is an autoinflammatory condition that originates inside the body, driven by the immune system and genetics rather than by any infectious agent.
This is one of the most common questions people have about HS, and for good reason. The painful, draining lumps it produces can look alarming, and they often appear in intimate areas like the groin, armpits, and buttocks. That combination leads to confusion, stigma, and sometimes misdiagnosis as a sexually transmitted infection. None of that is accurate.
Why HS Looks Infectious but Isn’t
HS lesions can ooze pus, which naturally makes people think of infection. But the process behind those lesions is entirely different from what happens with a bacterial or viral skin infection. The problem starts with hair follicles. In people with HS, hair follicles become blocked, and that blockage eventually causes the follicle to rupture beneath the skin. When the contents of the follicle spill into surrounding tissue, the immune system treats it like a foreign invader, launching an aggressive inflammatory response. That response, not bacteria or viruses, is what creates the painful abscesses and tunnels under the skin.
While bacteria can sometimes colonize HS wounds after they form, bacteria are not the root cause. This is a critical distinction. The immune system itself is misfiring, producing elevated levels of inflammatory signaling molecules in both the skin and bloodstream of people with HS. Those elevated inflammatory markers are what classify HS as an autoinflammatory disease, placing it in the same broad category as conditions like Crohn’s disease and rheumatoid arthritis.
HS Is Not an STI
Because HS commonly affects the groin, inner thighs, and buttocks, it gets mistaken for herpes, syphilis, or other sexually transmitted infections more often than it should. Some patients report being told by clinicians that their symptoms are sexually transmitted before eventually receiving the correct diagnosis. The average person with HS waits about 10 years from their first symptoms to getting an accurate diagnosis, often seeing more than three different doctors and receiving multiple misdiagnoses along the way.
The key differences are straightforward. STIs are caused by specific pathogens transmitted between people. HS is caused by follicular blockage and immune dysfunction that develops inside one person’s body. HS lesions tend to recur in the same general areas over months and years, forming deep nodules and interconnected tunnels beneath the skin. That pattern looks nothing like herpes blisters or syphilitic sores once a clinician familiar with HS examines them.
What Actually Causes HS
Genetics play a significant role. More than one-third of people with HS have a family history of the condition. Researchers have identified 57 mutations across several genes involved in a cellular process called gamma-secretase signaling, which affects how skin cells develop and how the immune system communicates. If a parent has HS, their children face a meaningfully higher chance of developing it as well. But inheriting a genetic predisposition doesn’t guarantee you’ll get HS. Environmental and lifestyle factors also contribute.
Smoking is one of the strongest modifiable risk factors. Continuing to smoke raises the risk of developing HS by roughly 24% compared to nonsmokers, and increasing the number of cigarettes smoked pushes that risk even higher, to about 29%. Body weight matters too. A meta-analysis of eight studies found that the odds of obesity among people with HS were 3.5 times higher than in the general population. Excess weight creates more friction and heat in skin folds, which can worsen follicular blockage. Hormonal shifts also seem to play a role, which partly explains why HS often first appears during puberty or early adulthood.
It’s Not Caused by Poor Hygiene
One of the most damaging misconceptions about HS is that it results from not washing properly. This is categorically false. Dermatologists who specialize in HS now make it a standard part of patient intake to explicitly address this myth, because the psychological toll of being told your disease is your fault can be devastating. One HS specialist has described a colleague on the HS Foundation board whose life was significantly affected for years after being told her condition came from not washing enough.
No amount of scrubbing will prevent or treat HS. In fact, aggressive washing can irritate already inflamed skin and make flares worse. The disease originates deep within hair follicles, in a process driven by immune dysfunction that soap cannot reach or influence.
How HS Progresses
Doctors classify HS severity using a three-stage system. In the earliest stage, you may have one or a few isolated abscesses with no scarring or tunnels connecting them. Many people stay at this stage, dealing with painful but relatively contained flares that come and go.
The second stage involves recurrent abscesses that start forming sinus tracts, which are narrow tunnels beneath the skin connecting separate lesions. Scarring becomes noticeable. In the most severe stage, large areas of skin are affected by interconnected networks of abscesses and tunnels, sometimes spanning an entire body region like the groin or armpits. Progression isn’t inevitable, but delayed diagnosis and untreated inflammation increase the risk of advancing to more severe stages.
How HS Is Managed
Treatment depends on severity and focuses on reducing inflammation and preventing new flares. For mild cases, topical treatments and antibiotics (used for their anti-inflammatory properties, not because HS is an infection) can help manage symptoms. Lifestyle changes like quitting smoking and maintaining a healthy weight can reduce flare frequency and severity.
For moderate to severe HS, biologic medications that target specific parts of the immune system have become the standard of care. Three biologics currently have FDA approval specifically for HS. The first targets a key inflammatory molecule called TNF-alpha, which is found at significantly higher levels in both the skin and blood of people with HS. Two newer options target a different inflammatory pathway involving IL-17, a signaling molecule also elevated in HS lesions. These medications are given by injection and can provide sustained symptom relief, though they don’t cure the underlying condition.
Surgery is sometimes necessary for severe or persistent lesions, particularly when deep sinus tracts have formed. The goal is to remove the affected tissue and allow healthy skin to heal in its place. For many people, the best outcomes come from combining medical treatment with surgery when needed.
Living with HS Around Others
If you have HS, you do not need to avoid physical contact with other people. You cannot transmit the condition through hugging, sharing towels, sexual activity, or any other form of contact. Partners, family members, and friends are at zero risk of “catching” HS from you. If someone in your household also develops HS, that reflects shared genetics, not transmission.
The fluid that drains from HS lesions is a product of your own immune response, not an infectious discharge. Keeping wounds clean and bandaged is good wound care practice for your own comfort and healing, but it’s not a precaution you need to take to protect others.