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Familial hidradenitis suppurativa
This condition involves deep, inflamed lesions that can lead to scarring, typically appearing in skin folds. It often runs in families and is caused by changes in specific genes involved in skin cell function and inflammation.
Overview
Familial hidradenitis suppurativa (HS) is a long-term (chronic) inflammatory skin condition. It leads to the formation of painful, deep-seated nodules, abscesses, and tunnels (fistulas) primarily in areas where skin rubs together, such as the armpits, groin, and under the breasts [PMID:34298194]. These lesions can be very uncomfortable and may rupture, draining pus and causing an unpleasant smell. Over time, repeated inflammation can lead to significant scarring and the development of further tunnels under the skin.
While hidradenitis suppurativa can affect anyone, the familial form indicates a genetic predisposition, meaning it tends to run in families. It generally begins after puberty, during or after adolescence, and can persist for many years. The severity of the condition varies widely among individuals, even within the same family.
Symptoms & clinical features
The main symptoms of familial hidradenitis suppurativa involve recurrent, painful skin lesions. These typically begin as small, tender bumps under the skin that can grow into deep, inflamed nodules or abscesses. These lesions often rupture, releasing pus and blood, which can be messy and have an odour. Healing can be slow and may result in scarring [PMID:34298194].
Over time, the condition can lead to the formation of open wounds and tracts, or 'tunnels', under the skin that connect different lesions (sinus tracts or fistulas). These tunnels can accumulate pus and bacteria, leading to persistent inflammation. The pain associated with HS can significantly impact daily activities and quality of life.
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Affected organs
Familial hidradenitis suppurativa primarily affects the skin, particularly areas rich in apocrine sweat glands and where skin rubs together. Common sites include the armpits (axillae), groin, inner thighs, buttocks, and beneath the breasts. In severe cases, lesions can appear on other parts of the body, such as the neck, face, and back [PMID:28790076].
The condition is not typically associated with internal organ damage. However, the chronic inflammation and pain can lead to complications such as secondary bacterial infections within the lesions, anaemia due to chronic inflammation, and psychological impacts like depression and anxiety. Severe scarring can also limit movement in affected joints.
Risks & severity
The severity of familial hidradenitis suppurativa can range from mild, with occasional small bumps, to severe, with widespread abscesses, extensive tunnelling, and debilitating pain. The condition often progresses in stages, and its course can be unpredictable. Early diagnosis and management are important to help prevent progression and reduce the impact of scarring.
Familial HS typically starts during or after puberty. While the exact prevalence of the familial form is not well established, having a family history of HS increases an individual's risk of developing the condition. There is often a higher risk and earlier onset in individuals with a genetic predisposition compared to those with non-familial forms.
Genetic causes
Familial hidradenitis suppurativa is primarily caused by genetic changes (variants) in genes involved in a cellular pathway known as the gamma-secretase complex. Key genes identified include NCSTN, PSEN1, and PSENEN [PMID:28790076]. These genes provide instructions for making components of the gamma-secretase complex, which is crucial for processing certain proteins, including Notch signalling proteins.
The Notch signalling pathway is vital for cell-to-cell communication and plays a role in the development and function of hair follicles and skin. When there are pathogenic variants in NCSTN, PSEN1, or PSENEN, the gamma-secretase complex may not function correctly. This can disrupt the Notch signalling pathway, leading to abnormal cell differentiation and increased inflammation within the hair follicles, which contributes to the development of HS lesions.
- NCSTN nicastrin
- PSEN1 presenilin 1
- PSENEN presenilin enhancer, gamma-secretase subunit
Inheritance pattern
Familial hidradenitis suppurativa is typically inherited in an autosomal dominant pattern. This means that a person only needs to inherit one copy of an altered gene from one parent to develop the condition. If a parent has a pathogenic variant in one of the associated genes, there is a 50% chance with each pregnancy that their child will also inherit the variant and be at risk of developing the condition.
The condition can sometimes 'skip' generations or show variable expressivity, meaning that while someone may inherit the genetic variant, they might experience milder symptoms than other affected family members. Genetic counselling can provide detailed information about inheritance patterns and risks for family members.
Each child has a 50% chance of inheriting the pathogenic variant, regardless of sex.
Diagnosis & testing
Diagnosing familial hidradenitis suppurativa generally involves a clinical assessment by a dermatologist, based on characteristic skin lesions and their location. A family history of similar symptoms can suggest a familial form. Genetic testing may be offered to confirm a diagnosis, particularly when a familial pattern is suspected, and to identify the specific genetic cause.
Genetic testing for familial HS falls under the NHS Genomic Medicine Service (GMS) pathways. Referrals for genetic testing are typically made by a specialist, such as a dermatologist or a clinical geneticist. The relevant NHS R-codes for genetic testing in complex skin disorders like HS can help guide clinicians in arranging appropriate genomic investigations.
Management & lifestyle
While there is currently no cure for familial hidradenitis suppurativa, management aims to control symptoms, reduce flare-ups, prevent progression, and improve quality of life. Treatment approaches are individualised and often involve a combination of medical therapies, lifestyle adjustments, and sometimes surgical interventions.
Medical treatments may include topical applications, antibiotics to manage infections, anti-inflammatory medications, and newer biological drugs that target specific inflammatory pathways. For severe or persistent lesions, surgical removal of affected skin areas or draining of abscesses may be considered. Support groups and psychological counselling can also be beneficial in managing the chronic nature of the condition and its impact on mental health. It is essential for individuals with familial HS to be under the care of a dermatologist experienced in managing this condition.
UK care pathway
In the UK, individuals suspected of having familial hidradenitis suppurativa will typically be referred to a dermatologist for clinical assessment. If a genetic cause is suspected, particularly with a strong family history, a referral to a clinical genetics service may be made. The NHS Genomic Medicine Service provides pathways for genetic testing, guided by national R-codes, to identify causative genetic variants.
Genetic counsellors are an integral part of the care team. They can help individuals and families understand the genetic basis of the condition, its inheritance pattern, the implications of a diagnosis, and discuss options for family planning and testing.
Frequently asked questions
What is the difference between hidradenitis suppurativa and familial hidradenitis suppurativa?
Familial hidradenitis suppurativa is a form of the condition that typically runs in families due to an inherited genetic change. Standard hidradenitis suppurativa can affect anyone, but does not always have a clear genetic inheritance pattern.
Can I pass familial hidradenitis suppurativa on to my children?
Since familial hidradenitis suppurativa is often inherited in an autosomal dominant manner, if you have a causative genetic variant, there is a 50% chance with each child that they will inherit the variant. A genetic counsellor can provide personalised risk information.
Are there triggers for flare-ups in familial hidradenitis suppurativa?
While the underlying cause is genetic, some individuals report certain triggers that can worsen symptoms. These may include smoking, excess weight, mechanical irritation from clothing, sweating, and hormonal changes. Identifying and managing these factors might help reduce flare-ups.
What kind of doctor should I see for familial hidradenitis suppurativa?
A dermatologist is generally the most appropriate specialist to manage hidradenitis suppurativa. If a genetic cause is suspected, they may refer you to a clinical geneticist for further assessment and genetic testing.
Will genetic testing help inform my treatment for familial hidradenitis suppurativa?
Genetic testing confirms the underlying genetic cause, which can be important for family planning and understanding the condition's inheritance. While current treatments largely focus on symptom management regardless of the specific genetic variant, understanding the genetic basis may inform future personalised medicine approaches.
References
- Koumaki D, Gregoriou S, Evangelou G. Familial Hidradenitis Suppurativa on the Island of Crete: Distinct Patterns in Clinical Characteristics. The Journal of dermatology. 2025. PMID: 41055247
- Pace NP, Mintoff D, Borg I. The Genomic Architecture of Hidradenitis Suppurativa-A Systematic Review. Frontiers in genetics. 2022. PMID: 35401657
- Desta B, Korytnikova E, Tessier-Kay M. The role of γ-secretase in familial hidradenitis suppurativa: Implications for pathogenesis and targeted therapy. JAAD case reports. 2026. PMID: 41537012
- Al-Gburi S, Ghaffari N, Schultheis M. Familial hidradenitis suppurativa is associated with an increased prevalence of metabolic and cardiovascular comorbidity. Journal der Deutschen Dermatologischen Gesellschaft = Journal of the German Society of Dermatology : JDDG. 2026. PMID: 42144829
- Azzarà A, Cassano I, Lintas C. Exome Profiling Suggests Combined Effect of Myeloperoxidase, Toll-Like Receptors, and Metallopeptidase in Hidradenitis Suppurativa. Biomedicines. 2024. PMID: 39595064
- Hessam S, Gambichler T, Skrygan M. Increased expression profile of NCSTN, Notch and PI3K/AKT3 in hidradenitis suppurativa. Journal of the European Academy of Dermatology and Venereology : JEADV. 2021. PMID: 32978818
- Pink AE, Simpson MA, Brice GW. PSENEN and NCSTN mutations in familial hidradenitis suppurativa (Acne Inversa). The Journal of investigative dermatology. 2011. PMID: 21412258
- Fitzsimmons JS, Fitzsimmons EM, Gilbert G. Familial hidradenitis suppurativa: evidence in favour of single gene transmission. Journal of medical genetics. 1984. PMID: 6492093