About hidradenitis suppurativa

Hidradenitis suppurativa (HI-dra-ned-i-tis SOUP-u-ra-ti-vah), or just “HS,” is a debilitating, chronic, complex inflammatory condition that causes painful, boil-like lumps (abscesses) that can come back repeatedly. HS affects many areas of life — your physical health, mental wellbeing, relationships, emotions and finances. 

HS can appear anywhere where hair follicles grow, except on the palms of your hands, soles of your feet or the darker parts of your lips. These abscesses may start as lumps that will either disappear or rupture and leak pus within hours or days. If these are not effectively treated, larger abscesses may form and spread. 

Tunnels (also called sinus tracts) may form between the abscesses. Chronic inflammation from abscesses typically leads to scar formation. 

HS is a condition caused by a combination of a dysfunctional immune system and altered cell behaviour around hair follicles. HS is not due to poor hygiene, HS is not due to obesity, and it is NOT contagious.  

Multiple factors, including genetics, hormones, environmental triggers and stress, are known to contribute to HS activity. 

HS can happen at any age. It rarely occurs in childhood but commonly occurs during puberty, and a small proportion of women find that it occurs after pregnancy or around the time of menopause. In some people, it is a progressive condition and can get worse over time without treatment. HS can make daily activities harder and have a significant impact on your mental health. 

HS can be associated with other immune conditions such as inflammatory bowel disease, arthritis and thyroid disease.  

In Australia, HS is thought to impact approximately 0.67 to 1 per cent of the population. However, getting a diagnosis can take years and many people with HS may be misdiagnosed. Therefore, the real number could be much higher.

HS is more common in biological women, young people, people with excess weight, people who smoke and people with low annual income. Genetics and ethnicity can also play a role. However, these factors don’t directly cause HS and don’t determine who can or cannot develop it. HS can affect anyone, anywhere, at any time. 

Unfortunately, misconceptions can prevent people from seeking treatment or getting a proper diagnosis. For example, some biological men are led to believe they cannot get HS. Similarly, some people are told that HS only affects certain racial or ethnic groups, discouraging others from seeking help. These ideas are not only inaccurate but also potentially harmful and can delay care. 

Regardless of who you are, if you experience symptoms of HS, it’s important to consult a doctor. For instance, if you’ve had two or more painful, boil-like abscesses in the past six months, it could be a sign of HS.

HS can impact one or multiple areas of the body. Symptom severity can vary widely among individuals. Some people may experience only mild symptoms, while others have more severe and frequent episodes. 

Here are some key signs and symptoms of HS.  

• Blackheads: Often seen in pairs, these appear as small, pitted areas of skin. They are called DEPs (double-ended pseudocomedones). 

• Painful, boil-like abscesses: The condition typically begins with a small, firm lump (nodule) or pustule (a nodule filled with pus) that may be skin-coloured. It can gradually darken and persist for weeks or months. Over time, more pustules may develop, ranging from the size of a pea to as large as a golf ball or a small orange. 

• Leaking lumps or sores: These pustules can get larger, break open and form abscesses that drain fluid and pus. They may also itch and have an unpleasant odour. 

• Tunnels: Over time, tunnels may form under the skin, connecting the abscesses. These tunnels heal very slowly, if at all, and can lead to scarring and fistulas. 

• Fistulas: These are abnormal passageways that form between two body parts, such as organs (including the skin), blood vessels, or cavities. Fistulas can cause bodily fluids, such as blood, pus or faeces, to flow where they are not meant to. 

HS severity is categorised into three stages (known as Hurley Stages). It is possible to have different Hurley stages on various parts of the body at the same time.

HS is diagnosed clinically using the modified Dessau criteria. This criterion outlines the presence of typical lesions (including pustules, abscesses and tunnels) in typical areas (such as the armpits, groin, buttocks and the folds around the breasts), affecting two discrete regions within a 6-month period. 

There is no blood or tissue test to diagnose HS. It can be challenging to identify in its early stages because it may resemble other skin conditions or infections. 

Not all medical professionals (including not all dermatologists) are familiar with HS and its treatment options. However, finding one who is can make a big difference. In many cases, HS symptoms in patients are first picked up by other health professionals, such as gynaecologists and GPs. In Australia, only dermatologists can give a definitive diagnosis. 

If your medical practitioner suspects HS, they will likely: 

• Review your family and medical history. Review your HS symptom history. 

• Examine your skin, including sensitive areas, to assess the type and severity of your symptoms. 

• Order pathology tests on blood, skin, or pus samples to help rule out other possible diagnoses, such as acne or an STD. 

• Refer you to a dermatologist to confirm the diagnosis and, if required, prescribe advanced treatment; specifically, one who specialises in HS. 

Your dermatologist should be able to easily recognise HS and understand that it’s a systemic condition (body-wide) caused by inflammation. They can create a custom treatment plan to manage your symptoms. They can even explain the latest research and treatment options, as well as any open clinical trials that may be relevant to you. 

Early diagnosis is crucial for effectively managing HS. Unfortunately, people live with HS symptoms for around seven years on average without a correct diagnosis — and by the time they are diagnosed, 70 per cent of patients already have moderate-to-severe disease. 

The good news? No matter the stage of HS, more new treatment options are becoming available to help you manage the condition and improve your quality of life. 

HS often presents alongside other health conditions, known as comorbidities. These are additional medical issues that occur at the same time as HS and can make managing the disease more challenging. 

HS comorbidities can occur for various reasons, including: 

• Shared disease pathways within the body. 

• Some of the treatments used for HS. 

• Lifestyle factors (such as smoking, alcohol or stress). 

• Other or unknown factors. 

• Combinations of the above. 

The risk of developing comorbidities varies from person to person, so it is important to discuss your risk with your doctors. Understanding these comorbidities is vital for ensuring you receive the most complete and effective care. Just because you have HS doesn’t mean you will develop these comorbidities. 

Some of the comorbidities linked to HS include: 

Skin conditions: HS may be associated with other skin issues such as acne vulgaris (AV, the most common type of acne with blackheads, whiteheads and cysts), acne conglobata (AC, a severe form of acne with interconnected nodules and abscesses that may cause scarring), dissecting cellulitis of the scalp (DCS, a chronic scalp condition with painful nodules and hair loss) and pilonidal cysts (PC, painful cysts near the tailbone often caused by ingrown hairs). 

Metabolic, cardiac, and endocrine conditions: These conditions are broadly defined by disruptions in metabolism, heart function and hormone regulation, respectively. These systems are closely interrelated. Examples linked to HS include obesity, metabolic syndrome, high cholesterol, type 2 diabetes, high blood pressure and polycystic ovarian syndrome. 

Autoimmune conditions: These occur when the immune system is disrupted and starts to attack healthy cells. Different conditions involve cells in various parts of the body. Examples of autoimmune conditions linked to HS include lupus, inflammatory bowel disease, and spondyloarthritis (inflammatory arthritis primarily affecting the spine and pelvic regions). 

Some medications may increase your chance of developing comorbidities, so always discuss your individual risks with your doctor when you start new medications.

Calao M, et al. Hidradenitis Suppurativa (HS) prevalence, demographics and management pathways in Australia: A population-based cross-sectional study. PLoS One. July 2018. https://doi.org/10.1371/journal.pone.0200683 

Cleveland Clinic. Fistula. https://my.clevelandclinic.org/health/diseases/fistula 

Frew J, et al. Australasian hidradenitis suppurativa management guidelines. Australasian Journal of Dermatology. November 2024. https://doi.org/10.1111/ajd.14388 

Vekic D, et al. Hidradenitis suppurativa – Management, comorbidities and monitoring. Australian Family Physician. https://www.racgp.org.au/afp/2017/august/hidradenitis-suppurativa-management-comorbidities