7 Places on the Body That Hidradenitis Suppurativa Can Appear

Despite what Instagram and photo filters would have us think, no one has perfectly smooth skin over the entirety of their body. We’re all prone to the occasional bump, rash, zit, or ingrown hair. These issues generally go away after the blocked follicle, clogged pore, or minor skin irritation resolves.

But hidradenitis suppurativa (HS) is different. HS is a chronic, progressive skin condition that typically appears as boil-like lumps in some of your most sensitive regions (and beyond).

HS lumps or bumps can form interconnected tracts underneath the skin that may become inflamed and infected, causing discomfort and pain. Although infections are often a part of HS, the disease itself is not an infection — it’s due to an ongoing inflammatory response in the body.

In addition to causing pain and discomfort, HS can be extremely frustrating and impact your self-esteem. Identifying HS correctly and early is crucial for getting optimal care, easing symptoms, slowing disease progression, and improving your mental health.

While we don’t know what exactly causes HS, genetic, environmental, and hormonal factors may play a role. Skin regions prone to HS include those where we sweat often and where friction is super common. Friction can occur from skin rubbing on skin, or where clothing can chafe or rub.

Here are seven areas of the body that are often impacted by HS.

Our underarms are packed with hair follicles and apocrine glands (aka, sweat glands). With HS, these follicles and glands may become clogged, and bacteria can start to grow, leading to the inflamed boil-like bumps of HS.

If you’ve ever gone for a run and come back with the dreaded armpit chafing, you’re all too familiar with how this area of the body can be prone to skin-on-skin friction or excessive rubbing from clothing. (Lookin’ at you, sports bra!) Friction and chafing can also cause an HS flare-up.

Complicating matters is that some people shave or wax their armpits, and many understandably slather this region with antiperspirants or deodorants. These factors can also clog or irritate sweat glands and hair follicles.

The breasts, including underneath and even on the areolae (the area around the nipple), are a common place for HS to show up.

The breast area is a frequent spot for chafing from bras or other clothing. This chafing not only causes skin irritation — it can also trap sweat and bacteria on the skin. The areolae contain apocrine glands and hair follicles that can easily become infected. All these factors can contribute to an HS flare.

Research also points to sex hormones playing a role in HS, so a hormone shift or imbalance may also make breast tissue more prone to HS lesions. However, more research is needed on the connection between HS and hormones.

No one can deny that the crotch becomes a sweaty area when life gets steamy, either from the weather, a workout, or both. It’s also a common area for clothing to rub against just from walking and everyday movements.

As with other HS-prone areas, the groin and genital areas contain apocrine glands and oodles of hair follicles, all of which can become blocked as part of HS, leading to a flare. Speaking of hair down there, many people groom their pubic region, which can also lead to blocked hair follicles.

Again, hormonal shifts or imbalances may also play a role in why these sensitive areas can become hot spots for HS.

The inner thighs are an extension of the groin area. Similarly, sweat also hangs out here, and it’s a common spot for chafing to occur from skin-on-skin friction, or from clothing rubbing and irritating the area.

The entire buttocks area is also prone to HS in many people. Areas commonly affected include the anus, the butt crack, and the gluteal fold — or the crease where the buttocks meet the backs of the upper thighs.

Apocrine glands and hair follicles are abundant here, too. Sweat and other bacteria sources can also lead to HS infections. The buttocks are also subjected to pressure from sitting, which can lead to further irritation.

Although more research is needed, some studies suggest a link between HS and inflammatory bowel disease (IBD). IBD is an umbrella term for conditions such as Crohn’s and ulcerative colitis. The potential links between HS and IBD may play a role in why the buttocks area is a common site for HS.

Although less common than in other areas, HS can also show up at the nape of the neck. This might be due to friction from clothing collars, jewelry, and other clothing or accessories. The neck is also a common site for sweat, which could block hair follicles in this area.

If skin folds at the waist, or clothing waistbands (especially tight ones!) cause friction, it can lead to HS in the waistband area. As a result, HS lesions may show up on the abdomen, back, or sides.

HS tends to appear on some of the body’s most sensitive places, including the underarms, breasts, groin, and buttocks. These areas are prone to sweat, friction, and irritation from hair removal — all of which may contribute to an HS flare.

If you suspect you have HS, talk with a knowledgeable dermatologist who can give you a proper diagnosis and help you develop the right treatment and self-care plan to combat irritation and flares so you can feel more comfortable in your skin.