Hidradenitis suppurativa (HS) is an inflammatory skin condition that causes painful lumps and boils to develop beneath the skin. These lumps usually appear in areas where skin rubs against skin, such as the armpits, groin, and under the breasts. Despite its resemblance to acne, HS is not directly related to acne, although the lumps can look and feel similar to pimples.
While the exact cause of HS remains unclear, certain factors, such as being assigned female at birth, smoking, and underlying health conditions, can increase the likelihood of developing this condition.
The Main Theory
why hair follicles become blocked
Hidradenitis suppurativa occurs when hair follicles become blocked, but researchers are still uncertain about why this blockage happens. When hair follicles are blocked, the body reacts with an inflammatory response that leads to swelling, pain, and pus-filled bumps or abscesses.
what causes the follicle blockages?
Researchers believe that a combination of factors, such as keratin (a protein), sweat, and bacteria, contribute to follicular blockages. As these substances build up and get trapped in the follicles, they form lumps or abscesses. In some cases, this buildup may leak out and block nearby follicles, causing multiple lumps to form in one area.
Even though these substances are naturally produced by the skin, most people with HS do not have underlying conditions affecting their sweat glands or keratin production. It is believed that people with HS have a heightened immune response to blocked follicles, triggering the inflammatory process that leads to HS.
Is HS Hereditary?
genetic factors
Hidradenitis suppurativa often runs in families. About 30-40% of individuals with HS have a first-degree relative (e.g., parent or sibling) with the condition. Experts suggest that HS may follow an autosomal dominant inheritance pattern in some families, meaning that only one parent with a genetic mutation can pass the condition on.
genetic mutation and inheritance
Studies estimate that individuals with HS have a 50% chance of passing on the genetic mutation associated with HS to their children. The genes involved in the development of HS include NCSTN, PSEN1, and PSENEN. However, inheriting a gene mutation does not guarantee that someone will develop HS. Many people with HS have no family history of the condition, indicating that both genetic and environmental factors contribute to its development.
Who Gets Hidradenitis Suppurativa?
age and gender factors
Anyone can develop HS, but certain factors increase the likelihood of developing the condition. Many people first experience symptoms during puberty, with the most common age range for diagnosis being 21 to 29 years old. HS can appear at any time before age 40.
gender differences
HS is more common in people assigned female at birth, with women being three times more likely to develop the condition compared to men. Fluctuating hormone levels, such as those experienced during menstruation, pregnancy, and menopause, may contribute to the higher prevalence in women.
racial and ethnic factors
Black individuals are at a higher risk of developing HS, particularly Black and biracial women, who experience the condition more often than other groups.
Risk Factors
environmental and individual factors
HS is influenced by a combination of environmental and genetic factors. Some common risk factors for HS include:
smoking
Smoking is a major environmental risk factor for HS. Around 70-90% of people with HS have a history of smoking or using tobacco products. Smoking can affect sweat gland production, increasing the risk of blocked hair follicles.
obesity
Obesity is associated with more severe symptoms of HS. It can also trigger other risk factors, including increased hormonal changes, skin-to-skin friction, and increased sweat and keratin production.
other follicle-related conditions
Certain conditions, such as severe acne, pilonidal sinus, and scalp diseases causing scarring and hair loss, are linked to a higher risk of developing HS.
inflammatory bowel disease (IBD)
Although having IBD does not directly increase the risk of HS, the two conditions are often found together, especially in smokers. Individuals with both conditions may experience overlapping symptoms due to shared risk factors.
psoriasis
Psoriasis is another skin condition linked to a higher risk of HS. Some individuals develop HS after being treated for psoriasis. Shared risk factors like smoking and obesity, as well as immune system inflammation, might contribute to the connection between these conditions.
A Quick Review
Hidradenitis suppurativa (HS) is a painful, chronic skin condition that causes bumps and abscesses under the skin. While the exact cause is still not fully understood, blocked hair follicles, combined with factors like genetics, hormonal changes, and environmental triggers, play a significant role in its development.
Individuals with a family history of HS, those who smoke, and those with other conditions like obesity or psoriasis are at higher risk. Though there is no cure for HS, various treatments are available to manage symptoms and improve quality of life.
