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Hidradenitis suppurativa: Who gets and causes

What causes hidradenitis suppurativa?

Mom sitting on couch with depressed teenage girl.
In the United States, young women who are African American or biracial are most likely to get hidradenitis suppurativa.
The cause of this disease is still a bit of a mystery. Scientists continue to study hidradenitis suppurativa (HS) so that they can better understand what happens inside the body. This understanding can help them:

  • Know exactly what causes HS

  • Develop better treatment

Based on what scientists have learned so far, we know that HS begins in hair follicles. These are tiny structures in our skin from which hair grows.

Here’s what scientists believe happens inside a hair follicle when HS develops:

  1. The hair follicle becomes clogged with keratin (a protein found in our skin, hair, and nails).

  2. As keratin and sweat (which can no longer flow out of the clogged hair follicle) build up, bacteria breed inside the hair follicle.

  3. When a hair follicle has more keratin, sweat, and bacteria than it can hold, the hair follicle bursts. This causes what looks like a deep, painful pimple (nodule) or painful and swollen lump filled with pus (abscess).

  4. The material that pours out of the ruptured hair follicle spreads to nearby hair follicles.

  5. As more hair follicles become clogged, more lumps form. As more hair follicles continue to clog and burst open, deep tunnels form in the skin. Some people develop infections in their skin.

  6. The lumps heal and re-appear. As this continues, the skin eventually scars. HS tends to begin in an area with thick, coarse hair, such as the armpits and groin. As the disease progresses, some people may see HS under their breasts. HS can also develop on the belly, face, or other areas.

Who gets hidradenitis suppurativa?

Some people have a greater risk of developing HS. Here’s what researchers have found can increase your risk of developing HS:

Blood relative with HS: This disease can run in families. Many people who develop HS have a family member with this disease.

If one of your birth parents has HS, you have a 1 in 2 chance of inheriting the genes that cause HS. Even if you inherit these genes, you may not get HS.

While having a blood relative with HS may increase your risk, it’s important to keep in mind that many people who develop this disease do not have a blood relative with HS.

Exposure to a trigger: To get HS, it seems that something must trigger it. Scientists believe that cigarette smoking is the most common trigger for HS. Researchers have found that between 70% and 90% of people who get HS smoke cigarettes.

Being overweight also seems to trigger HS. The more overweight you are, the higher your risk of developing HS and of having severe HS. This likely happens because the more overweight you are, the more inflammation you have in your body.

What triggers HS for one person may not trigger it for another.

Gender: Females get HS more often than males. It’s still not clear why this happens.

Hormones may play a role. This could explain why HS can flare before menstruation. It would also help explain why HS can be less severe during pregnancy and after menopause begins.

Age: Most people develop HS between puberty and before 40 years of age. It’s very rare for HS to begin before puberty.

Race: In the United States, African Americans, Hispanics, and people who are biracial develop HS more often than do white people. Studies find that African Americans tend to have more severe HS. African Americans who have HS also tend to have a greater risk of developing a type of skin cancer called squamous cell carcinoma. This skin cancer can develop where you’ve had HS for many years.

Psoriasis: If you have psoriasis, a condition that develops when skin cells grow too quickly, you have a higher risk of developing HS.

The research breakthroughs that have given us a better understanding of what causes HS have also led to advances in treating HS. Find out what treatment options are available at, Hidradenitis suppurativa: Treatment.

Getty Images

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Bowers J. “Tailor-made care.” Dermatol World. 2020;30(7);114-9.

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Goldberg SR, Strober BE, et al. “Hidradenitis suppurativa: Current and emerging treatments.” J Am Acad Dermatol. 2020;82(5):1061-82.

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Lyons AB, Shabeeb N, et al. “Emerging medical treatments for hidradenitis suppurativa.” J Am Acad Dermatol 2020;83:554-62.

Narla S, Price KN, et al. “Proceeding report of the fourth Symposium on Hidradenitis Suppurativa Advances (SHSA) 2019.” J Am Acad Dermatol (2020: [epub ahead of print] doi:10.1016/ j.jaad.2020.05.114.

Ravn Jørgensen A-H, Brøgger-Mikkelsen M, et al. “Patients with a familial predisposition to hidradenitis suppurativa have a distinct clinical phenotype.” J Am Acad Dermatol 2020: [epub ahead of print] doi: 10.1016/j.jaad.2020.04.022.