What Causes Hidradenitis Suppurativa?

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition that affects millions of people worldwide, yet its exact causes remain complex and multifaceted. This painful condition manifests as recurrent boils, abscesses, and scarring in areas where skin rubs together, such as the armpits, groin, and under the breasts. Understanding what triggers and perpetuates this condition is crucial for both patients and healthcare providers in developing effective management strategies.

The development of hidradenitis suppurativa involves a intricate web of factors that work together to create the perfect storm for this inflammatory disease. While researchers continue to uncover new insights about HS, current evidence points to a combination of genetic susceptibility, hormonal influences, immune system dysfunction, and environmental triggers. At Hazany Derm, we recognize that each patient's experience with HS is unique, requiring a personalized approach to understanding their specific contributing factors.

For many patients seeking answers about their condition, learning about the causes of hidradenitis suppurativa can provide both relief and empowerment. Knowledge about the underlying mechanisms helps dispel common misconceptions about HS being caused by poor hygiene or being contagious. Instead, it reveals HS as a legitimate medical condition with identifiable biological and environmental contributors that can be addressed through proper medical care and lifestyle modifications.

Genetic and Hereditary Factors

Genetics play a significant role in hidradenitis suppurativa development, with research showing that approximately one-third of patients have a family history of the condition. This hereditary component suggests that certain genetic variations can predispose individuals to developing HS throughout their lifetime. Scientists have identified several genes associated with increased HS risk, including those involved in immune system regulation and inflammatory responses. The genetic influence explains why some families see multiple members affected by this condition across generations.

The most well-studied genetic connections involve mutations in the gamma-secretase complex genes, particularly NCSTN, PSEN1, and PSENEN. These genes are responsible for producing proteins that regulate cell signaling and inflammation pathways in the skin. When these genes contain mutations, they can disrupt normal cellular processes and contribute to the chronic inflammation characteristic of hidradenitis suppurativa. However, having these genetic variations doesn't guarantee that someone will develop HS, indicating that other factors must also be present.

Research has also identified genetic links between hidradenitis suppurativa and other inflammatory conditions such as Crohn's disease and certain types of arthritis. This connection suggests that some individuals may have a genetic predisposition to inflammatory diseases in general, with HS being one possible manifestation. Dr. Salar Hazany often explains to patients that understanding their genetic risk factors can help guide treatment decisions and family planning considerations.

The hereditary nature of HS manifests in several important patterns:

• Autosomal dominant inheritance: Some families show a clear pattern where the condition passes from parent to child with a 50% probability
• Variable expression: Family members with the same genetic mutations may experience different severities of HS symptoms
• Incomplete penetrance: Not everyone who inherits HS-associated genetic variants will actually develop the condition
• Polygenic influences: Multiple genes likely contribute to HS risk, making the inheritance pattern complex

While genetic testing for hidradenitis suppurativa is not routinely recommended for all patients, it may be considered in cases with strong family histories or when multiple family members are affected. Understanding the genetic component helps patients realize that developing HS is not their fault and that they inherited a biological predisposition to this condition. At Hazany Derm, we use this genetic information to help families understand their risk patterns and make informed decisions about monitoring and early intervention strategies.

The genetic foundation of hidradenitis suppurativa also influences how patients respond to various treatments, as individual genetic variations can affect drug metabolism and inflammatory pathways. This personalized medicine approach is becoming increasingly important in HS management, allowing healthcare providers to tailor treatments based on each patient's unique genetic profile and disease characteristics.

Hormonal Influences and Triggers

Hormonal fluctuations play a crucial role in hidradenitis suppurativa development and progression, with the condition showing clear patterns related to hormonal life stages and changes. The disease typically begins after puberty, rarely occurs before adolescence, and often worsens during periods of hormonal instability such as menstruation, pregnancy, or menopause. Androgens, particularly testosterone and its metabolites, appear to significantly influence HS activity by affecting hair follicle function and sebaceous gland production. This hormonal connection explains why hidradenitis suppurativa affects women more frequently than men and why symptoms often correlate with menstrual cycles.

Estrogen levels also impact hidradenitis suppurativa, though the relationship is more complex than with androgens. Some women experience improvement in their HS symptoms during pregnancy when estrogen levels are elevated, while others may see worsening during the postpartum period when hormone levels drop dramatically. Birth control pills and hormone replacement therapy can either improve or worsen HS symptoms depending on the specific hormonal composition and individual patient factors. The team at Hazany Derm carefully evaluates each patient's hormonal history to identify potential triggers and therapeutic opportunities.

The timing of HS onset often coincides with major hormonal transitions in life, providing important clues about the condition's underlying mechanisms. Women frequently report that their symptoms began during puberty, worsened during pregnancy, or changed significantly during perimenopause. Men with HS may notice connections between their symptoms and stress-related hormonal changes or conditions that affect testosterone levels. Understanding these hormonal patterns helps healthcare providers predict disease progression and plan appropriate interventions.

Several specific hormonal factors contribute to HS development and severity:

• Androgen sensitivity: Increased sensitivity to male hormones can trigger hair follicle inflammation and blockage in HS-prone areas
• Insulin resistance: Higher insulin levels can worsen hormonal imbalances and contribute to inflammatory processes in the skin
• Stress hormones: Elevated cortisol levels from chronic stress can suppress immune function and exacerbate HS symptoms
• Thyroid dysfunction: Both overactive and underactive thyroid conditions can influence HS severity through metabolic and hormonal effects

Hormonal influences on hidradenitis suppurativa extend beyond sex hormones to include metabolic hormones like insulin and leptin. Many patients with HS also have insulin resistance or diabetes, conditions that create systemic inflammation and can worsen skin symptoms. The relationship between obesity, metabolic syndrome, and HS creates a complex interplay where hormonal dysfunction, inflammation, and mechanical factors all contribute to disease progression.

Managing the hormonal aspects of hidradenitis suppurativa often requires a multidisciplinary approach involving dermatologists, endocrinologists, and gynecologists. Anti-androgen medications, insulin-sensitizing drugs, and carefully selected hormonal contraceptives can all play roles in HS management when hormonal factors are identified as significant contributors. At Hazany Derm, we work closely with other specialists to address the full spectrum of hormonal influences affecting our HS patients.

Environmental and Lifestyle Factors

Environmental and lifestyle factors significantly contribute to hidradenitis suppurativa development and can dramatically influence disease severity and progression. Smoking stands out as one of the most important modifiable risk factors, with studies showing that over 80% of HS patients are current or former smokers. The chemicals in tobacco smoke promote inflammation throughout the body and may directly affect hair follicle function in areas prone to HS development. Mechanical friction from tight clothing, excessive sweating, and repetitive skin trauma in fold areas can trigger and worsen HS lesions by creating an environment conducive to bacterial overgrowth and inflammation.

Obesity represents another major environmental risk factor that creates multiple pathways for HS development and progression. Excess weight increases mechanical friction in skin fold areas, promotes systemic inflammation through adipose tissue, and contributes to hormonal imbalances that can worsen HS symptoms. The relationship between obesity and HS creates a challenging cycle where the condition can limit physical activity due to pain and discomfort, potentially leading to further weight gain. Additionally, certain medications, stress levels, and occupational exposures to chemicals or irritants may serve as environmental triggers for susceptible individuals.

Diet and nutrition have emerged as important environmental factors in hidradenitis suppurativa, though the relationships are complex and vary among individuals. Some patients report improvements when avoiding dairy products, refined sugars, or foods high in glycemic index, while others benefit from anti-inflammatory dietary patterns. The gut microbiome's influence on systemic inflammation may explain why dietary modifications can impact HS symptoms in some patients. Hazany Derm specialists often work with patients to identify personal dietary triggers and develop sustainable nutritional strategies that support overall skin health.

Key environmental and lifestyle factors that influence HS include:

• Smoking and nicotine exposure: Direct inflammatory effects on skin and impaired wound healing significantly worsen HS outcomes
• Mechanical trauma: Tight clothing, aggressive shaving, and repetitive friction in fold areas can trigger new lesions and prevent healing
• Heat and humidity: Excessive sweating and moist environments promote bacterial growth and can exacerbate existing HS lesions
• Chemical exposures: Harsh soaps, deodorants, and occupational chemicals may irritate sensitive skin and trigger inflammatory responses

The role of bacterial colonization in hidradenitis suppurativa represents an important environmental factor that bridges the gap between external triggers and internal immune responses. While HS is not primarily an infectious disease, certain bacteria can colonize HS lesions and contribute to ongoing inflammation and secondary infections. The disrupted skin barrier in HS-affected areas makes patients more susceptible to bacterial overgrowth, creating a cycle where environmental bacteria worsen the condition while the condition creates an environment favorable to bacterial growth.

Stress management and sleep quality also function as important environmental factors in HS management, as chronic stress and poor sleep can worsen inflammatory conditions throughout the body. Many patients notice correlations between stressful life events and HS flares, suggesting that psychological stress may serve as a trigger through its effects on immune function and hormone levels. At Hazany Derm, we emphasize the importance of comprehensive lifestyle modifications that address not only direct physical triggers but also the broader environmental factors that can influence HS progression and treatment outcomes.