Hidradenitis suppurativa is a chronic skin condition that causes painful lumps, abscesses, and scarring in areas where skin rubs together, affecting millions of people worldwide and significantly impacting their daily lives and emotional well-being.
Understanding Hidradenitis Suppurativa
Hidradenitis suppurativa, also known as acne inversa or Verneuil disease, is a long-lasting inflammatory skin condition that affects areas of the body where skin touches skin. The condition causes painful lumps that form under the skin, which can break open and leak fluid. These lumps typically appear in places like the armpits, groin, buttocks, and beneath the breasts. The condition is not an infection, is not contagious, and has nothing to do with poor hygiene—facts that many people living with hidradenitis suppurativa wish others understood.[1][3]
The condition gets its name from the hair follicles where it develops, though for many years doctors mistakenly believed it originated in sweat glands. Today we know that hidradenitis suppurativa is an autoinflammatory disease, meaning the body’s immune system mistakenly attacks its own hair follicles, causing inflammation and the symptoms people experience. This understanding has helped researchers develop better treatments, though there is still no cure for the condition.[11]
Epidemiology: Who Gets Hidradenitis Suppurativa
Hidradenitis suppurativa affects approximately 1 in 100 people globally, though the exact numbers vary depending on location and how the condition is tracked. The disease does not affect everyone equally. Women are three times more likely than men to develop hidradenitis suppurativa, though this ratio can differ by geographic region. The reason for this gender difference likely relates to hormonal factors, though researchers are still working to understand the complete picture.[1][5]
Race and ethnicity also play a significant role in who develops hidradenitis suppurativa. Black people and those of mixed racial backgrounds are more likely to have the condition than people of other races. This may be due to genetic factors that make certain populations more susceptible. The condition typically begins after puberty, most commonly appearing when people are in their teens or twenties, though it can also develop later in life, even in someone’s forties or fifties. Very rarely does it appear before puberty begins.[1][3][4]
Geography and access to healthcare may affect how the condition is diagnosed and reported. Many people with hidradenitis suppurativa go years before receiving a correct diagnosis because the early symptoms can look like ordinary pimples or boils. This delay in diagnosis means that the true prevalence of the condition worldwide may be higher than reported numbers suggest.[2]
Causes of Hidradenitis Suppurativa
The exact cause of hidradenitis suppurativa remains unknown, but researchers have identified what happens in the skin when the condition develops. The painful lumps form because hair follicles become blocked. When a follicle is blocked, bacteria that normally live on the skin get trapped inside. This triggers inflammation and causes the follicle to rupture beneath the skin surface. The rupture spreads inflammation and infection to nearby areas, leading to the formation of more lumps.[1][3]
In most cases, doctors cannot identify why the hair follicles become blocked in the first place. Several factors appear to contribute. Genetics plays a role—about 30% of people with hidradenitis suppurativa have a family member who also has the condition. Some cases are caused by changes in specific genes, though these genetic changes have only been identified in a minority of affected individuals.[3][4]
Hormones, particularly sex hormones like estrogen and androgens (male hormones that both men and women have), may play a part. The fact that hidradenitis suppurativa usually starts after puberty and is more common in women suggests that hormonal changes influence the condition. Some women notice their symptoms worsen before their menstrual periods, and the condition sometimes improves during pregnancy or after menopause, further supporting the role of hormones.[1][5][11]
Environmental factors and the immune system also appear to contribute, though exactly how remains a subject of ongoing research. What is clear is that hidradenitis suppurativa is not caused by an infection that can spread to others, nor is it the result of poor personal hygiene. These are common misconceptions that cause unnecessary shame and misunderstanding for people living with the condition.[4][11]
Risk Factors
While anyone can develop hidradenitis suppurativa, certain factors significantly increase the risk. Smoking is one of the strongest risk factors. The vast majority of people with hidradenitis suppurativa either currently smoke or have smoked in the past. Smoking appears to worsen symptoms and make flare-ups more frequent and severe. Quitting smoking is considered essential for anyone trying to manage their condition effectively.[5][13]
Being overweight or having obesity (excessive body fat that can harm health) is another major risk factor. Excess weight can increase friction in areas where skin rubs together, potentially triggering or worsening symptoms. Additionally, obesity is associated with increased inflammation throughout the body, which may contribute to the inflammatory nature of hidradenitis suppurativa. Losing weight, when appropriate, may help reduce the frequency and severity of flare-ups.[3][5]
Having a family history of hidradenitis suppurativa increases risk considerably. As mentioned earlier, roughly one in three people with the condition have a relative who also has it. This familial pattern suggests that inherited genetic factors make some people more susceptible to developing the condition.[3][4]
Certain other medical conditions appear alongside hidradenitis suppurativa more often than would be expected by chance. People with hidradenitis suppurativa have higher rates of severe acne, excessive hair growth called hirsutism, inflammatory bowel diseases like Crohn’s disease, diabetes, heart disease, and certain types of arthritis. The connections between these conditions are not fully understood, but may relate to shared inflammatory or immune system processes.[5][18]
Symptoms and Clinical Presentation
The symptoms of hidradenitis suppurativa can range from mild to severe, and they tend to come and go in cycles. The condition usually begins with small, painful lumps under the skin that feel like peas. These lumps develop in areas where skin rubs against skin: the armpits, groin, buttocks, under the breasts, and around the genitals and anus. Sometimes lumps also appear on the nape of the neck, waistband, or inner thighs.[1][2]
In the earliest stages, people may notice small pitted areas of skin containing blackheads. These blackheads often appear in pairs and are a characteristic sign of hidradenitis suppurativa. Following this, painful, pea-sized lumps develop beneath the skin. These lumps may last for weeks or even months. They can remain small and eventually disappear, or they can grow larger and more painful.[1][5]
As the condition progresses, the lumps often break open and leak pus or other fluid. This drainage may have an unpleasant odor. The affected areas can become itchy. When lumps rupture, they form abscesses (pockets of pus), which can be extremely painful. The healing process is typically very slow, and the same areas tend to break out repeatedly over time.[3][5]
In moderate to severe cases, narrow channels called sinus tracts or tunnels form under the skin, connecting different lumps and abscesses. These tunnels can break through to the skin surface and leak pus. Over time, repeated inflammation and healing lead to significant scarring. The scarring can become thick and rope-like, and may restrict movement in severe cases.[2][5]
The pain associated with hidradenitis suppurativa can be constant for some people, while others experience pain only during flare-ups. The location of the lumps can make sitting, walking, or moving the arms extremely uncomfortable. Some people experience such severe symptoms that they have difficulty performing daily activities or going to work. The unpredictability of flare-ups adds to the distress, as people never know when symptoms might suddenly worsen.[2][18]
Beyond physical symptoms, hidradenitis suppurativa takes a significant emotional and psychological toll. The pain, drainage, odor, disfigurement, and scarring can lead to feelings of embarrassment and isolation. Many people with the condition develop depression and anxiety. The location of lesions in sensitive, private areas adds to the emotional burden, making it difficult for some people to discuss their condition even with healthcare providers or loved ones.[2][3]
Prevention and Risk Reduction
While there is no guaranteed way to prevent hidradenitis suppurativa from developing or to completely prevent flare-ups, certain lifestyle modifications may help reduce the frequency and severity of symptoms. For people already diagnosed, these measures are considered an important part of disease management.[17]
Quitting smoking is perhaps the single most important step someone with hidradenitis suppurativa can take. Smoking is strongly associated with worse symptoms and more frequent flare-ups. Healthcare providers consider smoking cessation essential for anyone trying to manage their condition. While quitting can be challenging, the potential improvement in symptoms makes it worthwhile.[5][13]
Maintaining a healthy weight helps reduce friction in areas where skin touches skin. For people who are overweight, even modest weight loss may lead to fewer and less severe flare-ups. Weight management also helps address the chronic inflammation associated with obesity, which may contribute to hidradenitis suppurativa symptoms.[3][17]
Identifying and avoiding personal triggers is important, though triggers vary from person to person. Common triggers include tight clothing that causes friction, excessive sweating, stress, and certain foods. Wearing loose-fitting, breathable clothing made from natural fibers can reduce skin irritation. Some people find that avoiding heat and humidity helps prevent flare-ups. Stress management techniques like meditation, yoga, or deep breathing exercises may also be beneficial, as stress can trigger or worsen symptoms.[15][17][21]
Gentle skin care practices may help. Keeping affected areas clean using mild, fragrance-free antibacterial soaps can reduce bacteria on the skin surface. Some people benefit from using antiseptic washes recommended by their healthcare provider. Avoiding shaving in affected areas or using an electric trimmer instead of a razor may reduce irritation. Using antiperspirants with aluminum chloride may help keep areas dry, though it’s important to choose products that don’t irritate the skin.[13][15][16]
Some people with hidradenitis suppurativa find that certain dietary changes help manage their symptoms, though research in this area is limited. Adopting an anti-inflammatory diet that focuses on whole, unprocessed foods—including plenty of fruits, vegetables, lean proteins, and foods rich in omega-3 fatty acids—may be beneficial. Some individuals report improvements after avoiding dairy products or foods high in refined sugars and processed ingredients, though these observations have not been confirmed by large scientific studies.[17]
Pathophysiology: What Happens in the Body
Hidradenitis suppurativa is fundamentally a disorder of the hair follicle in areas of the body that contain specialized structures called folliculopilosebaceous units (structures that include the hair follicle, hair shaft, and associated oil glands). The disease process begins with blockage of these hair follicles. When a follicle becomes plugged, the cells and oils that would normally be shed cannot escape.[2][5]
As material builds up in the blocked follicle, the follicle wall becomes stretched and weakened. Eventually, the follicle ruptures beneath the skin surface. When this rupture occurs, the contents of the follicle—including bacteria, dead cells, and inflammatory substances—spill into the surrounding tissue. This triggers an intense immune response and inflammatory reaction.[3][11]
The body’s immune system recognizes the spilled follicular contents as foreign material and rushes specialized immune cells to the area. These immune cells release inflammatory chemicals that cause swelling, redness, pain, and heat—the classic signs of inflammation. The immune response leads to the formation of the painful nodules and abscesses characteristic of hidradenitis suppurativa.[11]
Bacteria that normally live on the skin surface can enter the ruptured follicles and surrounding inflamed tissue. While bacteria do not cause hidradenitis suppurativa, their presence can worsen the inflammation and lead to secondary infections that require treatment with antibiotics. This is why the condition sometimes produces pus-filled abscesses that smell unpleasant.[3][5]
As the inflammatory process continues and lesions repeatedly form and heal, the body attempts to repair the damage through scarring. However, the ongoing cycles of inflammation prevent proper healing. Instead of normal skin forming, thick, fibrous scar tissue develops. In advanced cases, the inflammation and scarring create tunnels under the skin called sinus tracts that connect different areas of involvement.[2][5]
Recent research has shown that hidradenitis suppurativa involves dysfunction of the immune system, particularly an overproduction of inflammatory proteins called cytokines (chemical messengers that regulate immune and inflammatory responses). Two specific cytokines, interleukin-17A and interleukin-17F, appear to play important roles in driving the inflammation seen in hidradenitis suppurativa. This understanding has led to the development of new medications that target these specific inflammatory pathways.[14]
The disease tends to affect areas of the body where skin rubs against skin—so-called intertriginous areas. The friction and moisture in these areas may contribute to follicle blockage and create an environment that promotes inflammation. This explains why the armpits, groin, buttocks, and under-breast areas are most commonly affected.[2]
