Hidradenitis suppurativa (also known as acne inversa) is likely caused by multiple factors, including genetics, diet, and other environmental influences. Triggers are not at the root of why hidradenitis suppurativa (HS) develops in the first place, but they may lead to flare-ups or worsening of current symptoms (such as cysts that can become painful abscesses). There are many types of triggers: genetic, physical, dietary, and behavioral.

Members of myHSteam often talk about the factors that trigger their symptoms. “I think my main trigger is stress, but that’s hard to avoid when you deal with HS,” wrote one member. Another said, “So far, my biggest triggers are potatoes and tomatoes. I’m pretty sure sugar plays a part as well.”

Genetic Triggers for HS

It is believed that HS develops in people who are genetically susceptible to it, and that it often appears after that person has encountered trigger factor(s). Changes at the DNA level may be associated with HS, and these differences may be recorded in a person’s family history. Complicating conditions that are associated with more severe HS symptoms may act as trigger factors for sudden flare-ups.

For example, metabolic syndrome and some hormonal changes have been reported as factors that contribute to worsening HS symptom development. Thyroid disease is also said to be associated with more severe symptoms of HS.

Lifestyle Triggers for HS

Lifestyle triggers for HS may include those that are physical, dietary, and behavioral.

Physical Factors

Physical factors that can make flare-ups worse include friction from coarse clothing rubbing against your skin, sweating, and shaving. Topical application of some types of lotions, deodorants, and creams may also trigger a person’s HS to flare. (This is especially true with products that contain artificial fragrances.)

“Deodorant is a trigger for me,” one myHSteam member wrote. “I use natural deodorant — anything else causes a flare-up.”

Dietary Factors

Some aspects of diet may also play a role in HS flares. Potential dietary triggers include eating dairy or foods with brewer’s yeast, like breads, beer, and fermented cheese.

“I love cheese, but it does not love me,” one myHSteam member said. “Cheese triggers the worst HS outbreaks.”

People with digestive problems also reported worsening HS symptoms when their digestive diseases flared up.

Behavioral Factors

Cigarette smoking and obesity are also known trigger factors for HS. In fact, smoking is the most documented behavioral risk factor for HS. People living with HS who actively smoke have more areas of the body affected than those who have never smoked or who have quit smoking. Active smoking is also associated with a less effective reaction to various HS treatment options. It is therefore recommended that people living with HS stop smoking.

“I think this flare-up was so bad because I had almost quit smoking, and then started smoking again,” wrote one myHSteam member.

The use of some medications that help activate the immune system can also be a trigger factor for HS. For example, anti-PD-1 therapies (medications commonly used to treat some cancers) may trigger HS symptoms.

Other potential triggers include vitamin D deficiency, some medications, physical trauma, and bacterial infections. In addition, stress may be a trigger for some people living with HS.

How Do Triggers Cause HS Flare-Ups?

Researchers are working to understand the connection between trigger factors and HS flare-ups. Physical things — thickening skin, friction due to shaving, or skin rubbing together — that cause hair follicles to get blocked can trigger an HS flare-up. That’s because a blocked hair follicle signals to your body that it is damaged, which in turn sets off your immune system, and its response leads to inflammation. Invading bacteria can also play a role by infecting damaged skin and triggering inflammation. Inflammation can result in the hallmarks of HS: painful, swollen nodules and abscesses. The lesions scar and destroy a person’s skin where they appear.

The effect of smoking on HS symptoms and flare-ups is one of the most studied triggers. It is known that cigarette smoke contains thousands of chemicals. And it’s known that those chemicals affect a person’s skin cells and immune cells. Tobacco smoke and nicotine promote proinflammatory molecules found in HS lesions, causing even more inflammation.

Obesity is thought to trigger HS flare-ups because people who are obese often have more areas of skin that rub together compared to those who are not obese. They also sweat more than their non-obese counterparts. Both rubbing and sweating cause friction, and friction spurs on an HS flare. Smoking and obesity also lead to other changes that can lead to follicle blockage or ruptures. Such changes can include shifts in a person’s gut microbiome, low levels of chronic inflammation around their hair follicles, and thickening of their skin. These changes can lead to blockage or rupture of the hair follicles.

Avoiding Triggers Can Help

Many people with HS find that making long-term changes to their diets (such as eliminating certain foods) improved their HS symptoms.

One study looked at how eliminating food from one or more food groups would affect a person’s HS.

The top 5 food groups that participants considered were:

• Gluten
• Dairy
• Refined sugars
• Tomatoes
• Alcohol

About 31 percent of that study’s participants said that these dietary changes made their symptoms “much better.” The researchers cited this as a significant portion of participants, which means they believed the results were worth considering when treating HS. However, other participants reported their symptoms worsened when they made dietary changes.

Thorough studies have not been conducted to determine which dietary factors affect HS symptoms. There are plentiful reports of worsening symptoms being linked to certain food types, such as sweets, breads, pasta, rice, dairy, and high-fat foods. But what type of food helps or harms a person’s HS varies from individual to individual. People living with HS may benefit from dietary counseling, in addition to their dermatologist’s recommendations. Some people living with HS suggest using a daily food diary to help identify dietary triggers.

“Keeping a diary of foods I eat,” said one myHSteam member. Another wrote, “Still keeping a food journal.”

Systematic reviews have shown a strong association between obesity and symptomatic HS. Some people living with obesity and HS report that weight loss later helped improve their symptoms of HS.

“I lost 85 pounds on my own about 10 years ago,” one myHSteam member wrote. “I did see a difference with the flare-ups when I lost the weight.”

Overall, smoking cessation, losing weight, eating a healthy diet, reducing physical stress that causes friction, and regularly taking care of your skin could help reduce your symptoms of HS or decrease the occurrence of your flare-ups.

Talk With Others Who Understand

On myHSteam, the social network for people with hidradenitis suppurativa and their loved ones, more than 23,000 members come together to ask questions, give advice, and share their stories with others who understand life with hidradenitis suppurativa.

Have you found out your HS triggers? Do you have any advice on how to avoid common triggers? Share your experience in the comments below, or start a conversation by posting on your Activities page.