There are various potential hidradenitis suppurativa (HS) causes to be aware of, because there isn’t just one single factor that fuels the development of the skin condition. Researchers still have a lot of questions about why HS occurs in certain people, including how its root causes can help experts better understand hidradenitis suppurativa treatment options.
Hidradenitis suppurativa is a chronic condition that is characterized by painful lumps that form under the skin. Symptoms typically occur on areas of the body where your skin rubs together (like the armpits, groin region, under the breasts, or on the butt) and the bumps or sores can leak pus or odorous fluid, according to the Mayo Clinic. In severe cases, tunnels may develop under the skin, connecting the lesions to one another.
Somewhere between 1% to 4% of people in the U.S.1 have hidradenitis suppurativa, and for many of them, it can be physically and emotionally painful. People with hidradenitis suppurativa often say they feel self-conscious about the way their skin looks because of the stigma associated with the condition. That’s why understanding the risk factors for hidradenitis suppurativa—and knowing that you aren’t to blame for having the condition—is so important. Here’s what experts know about hidradenitis suppurativa causes so far.
What do experts know about hidradenitis suppurativa causes?
There is no clear-cut answer for what causes hidradenitis suppurativa, both in terms of what causes individual bumps to form and in what causes the condition to appear in certain people but not others. Experts previously theorized that hidradenitis suppurativa developed when apocrine sweat glands2—which are found in the armpits, groin, and breasts (the most commonly affected areas)—became infected. However, researchers later discovered the condition originates in hair follicles, not in the apocrine sweat glands, which led to the current theory that individual lumps are caused by blocked hair follicles3.
But that is only part of the story, Christopher Sayed, M.D., associate professor of dermatology at the University of North Carolina at Chapel Hill, tells SELF. In addition to follicular occlusion, meaning the hair follicles become blocked and then ruptured, the development of hidradenitis suppurativa is also associated with having some kind of inflammation in the body, Dr. Sayed explains.
Generally, your immune system attacks foreign substances it perceives as harmful, such as pathogens like the flu virus, to try to keep you healthy, according to the Cleveland Clinic. During this process, your immune cells set off an inflammatory response to try to facilitate healing, which can sometimes cause redness, swelling, and pain.
With hidradenitis suppurativa, however, researchers think your immune system overreacts to benign situations, like blocked hair follicles, and sets off the inflammation process in that general area as a result. Over time, chronic inflammation can cause more abscesses to form2, which in turn can lead to more pain, swelling, and other uncomfortable symptoms, depending on the hidradenitis suppurativa stage you’re in. This is why hidradenitis suppurativa is considered an inflammatory condition. (Just to be clear, hidradenitis suppurativa isn’t considered to be an autoimmune disease, which is when your immune system mistakenly attacks healthy cells in your body.)
It’s also important to understand that hidradenitis suppurativa is not a disease that is caused by a person’s individual behaviors—and you definitely can’t spread it to others. For example, you can’t develop the condition from having poor hygiene and you can’t pass it on through bodily contact because it’s not contagious, according to the Mayo Clinic. “If improved hygiene fixed hidradenitis suppurativa, there’d be no hidradenitis suppurativa,” says Dr. Sayed.