ConditionSkin, hair & nails
Hidradenitis Suppurativa (HS)
Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease that causes painful lumps, abscesses and, over time, tunnels and scars in skin folds, especially the armpits, groin, buttocks and under the breasts. It starts in blocked hair follicles, not sweat glands, and is not caused by poor hygiene or infection. It usually begins after puberty, affects women more than men, and is linked to smoking and obesity. Early diagnosis and treatment with antibiotics, biologic medicines and surgery can control flares and limit scarring.
Also called: HS, acne inversa, Verneuil disease
At a glance
- What it is
- A chronic inflammatory disease of hair follicles in skin folds, causing recurrent painful nodules and abscesses.
- Where
- Armpits, groin, inner thighs, buttocks, under the breasts.
- Who gets it
- About 1 in 100 people; onset usually in the teens to 30s; more common in women and Black people.
- Stages
- Hurley I (isolated lumps), II (recurrent abscesses with tunnels), III (widespread tunnels and scars).
- Treatment
- Antiseptic washes, antibiotics, hormonal therapy, biologics (adalimumab, secukinumab, bimekizumab), and surgery.
When to get help
See a doctor within a day or two
- A rapidly spreading area of redness, heat and swelling with fever or chills (possible cellulitis)
- A large, extremely painful abscess
Book a routine appointment
- Painful lumps in the armpits, groin or under the breasts that keep coming back in the same places
- Lumps that leak pus or blood, or leave rope-like scars
- Flares affecting work, relationships or sleep, or causing low mood
- A non-healing sore in a long-standing HS area (rarely, skin cancer can develop)
Usually safe to manage at home
- A single small, tender lump in a known HS area while you use warm compresses and your usual treatment plan
What hidradenitis suppurativa looks like
HS is often mistaken for boils or ingrown hairs at first. Typical features:
- deep, painful, pea-sized lumps under the skin
- lumps that enlarge, fill with pus and may burst, sometimes with an unpleasant odor
- recurrence in the same areas over months
- sinus tracts (tunnels) connecting lumps under the skin, draining persistently
- double-headed blackheads (paired comedones)
- rope-like or pitted scars
The pain and drainage can significantly affect daily life, sleep, intimacy and mental health.
Hurley stages
| Stage | Description |
|---|---|
| Hurley I | Single or multiple separate abscesses, without tunnels or scars |
| Hurley II | Recurrent abscesses with tunnels and scarring, separated by normal skin |
| Hurley III | Widespread, interconnected tunnels and abscesses across an entire area |
Causes and risk factors
HS starts when a hair follicle becomes blocked and ruptures, triggering intense inflammation. It is not an infection, though bacteria can colonize the lesions. Contributing factors:
- genetics: about a third of people have a family member with HS
- hormones: onset after puberty, and flares around periods
- smoking: strongly associated with HS and with more severe disease
- obesity: increases friction and inflammation, but HS also affects people of normal weight
- friction from tight clothing
It is associated with Crohn's disease, inflammatory arthritis, metabolic syndrome, diabetes, polycystic ovary syndrome, depression and anxiety.
Hidradenitis vs boils
| Hidradenitis suppurativa | Boils | |
|---|---|---|
| Cause | Chronic follicle inflammation | Bacterial infection (staph) |
| Recurrence | Repeated, same areas | Usually occasional |
| Location | Skin folds | Anywhere |
| Tunnels and scars | Common | Rare |
| Response to antibiotics alone | Partial, temporary | Usually good |
See boils and folliculitis.
Diagnosis
HS is diagnosed clinically, based on:
- typical lesions (nodules, abscesses, tunnels, scars)
- typical locations
- recurrence (at least twice in 6 months)
Swabs may be taken if infection is suspected. Ultrasound can show tunnels and guide treatment. There is no blood test. Average delays to diagnosis have historically been many years, so seeing a dermatologist early helps.
Treatment
Treatment depends on severity and is usually combined.
Skin care and lifestyle
- antiseptic washes such as chlorhexidine or benzoyl peroxide
- loose clothing, avoiding friction
- stopping smoking
- weight loss if overweight, which can reduce flares
- warm compresses and pain relief for flares
- dressings for draining areas
Medicines
- topical clindamycin for mild disease
- oral antibiotics: tetracyclines (doxycycline) for weeks to months, or clindamycin with rifampin for more severe disease
- hormonal treatments: combined oral contraceptives or spironolactone in women
- metformin, especially with insulin resistance
- steroid injections into individual inflamed lumps for rapid relief
- biologics for moderate to severe HS: adalimumab, secukinumab and bimekizumab are FDA-approved and can substantially reduce flares
- retinoids in selected cases
Procedures and surgery
- deroofing: removing the roof of a tunnel to let it heal from the base
- excision of affected areas, from local to wide excision for severe disease
- laser hair removal and CO₂ laser for some lesions
Incision and drainage gives short-term relief for a painful abscess but does not prevent recurrence.
Living with HS
HS is a long-term condition with flares and calmer periods. Many people benefit from mental health support and patient communities. Treatment has advanced considerably, and earlier treatment, especially with biologics, can prevent progression to scarring stages.
Frequently asked questions
What causes hidradenitis suppurativa?
HS is caused by blocked hair follicles in skin folds that rupture and trigger chronic inflammation. Genetics, hormones, smoking, obesity and friction all contribute. It is not caused by poor hygiene and is not contagious.
Is hidradenitis suppurativa contagious?
No. HS is an inflammatory condition, not an infection, and cannot be spread to other people, even though the lumps can drain pus.
Can hidradenitis suppurativa be cured?
There is no cure, but treatment can control it well. Stopping smoking, weight loss, antibiotics, hormonal therapy, biologics and surgery reduce flares and scarring. Surgical removal of affected skin can stop disease in that area.
How do I know if I have HS or boils?
HS lumps recur in the same skin-fold areas, such as the armpits and groin, form tunnels and scars, and respond only partly to antibiotics. Boils are usually occasional infections anywhere on the body that heal fully. A dermatologist can confirm HS.
Sources
This guide was written from current patient and clinical guidance, including:
- American Academy of Dermatology: Hidradenitis suppurativa, diagnosis and treatment
- North American Clinical Management Guidelines for Hidradenitis Suppurativa (US and Canadian HS Foundations, 2019)
- MedlinePlus: Hidradenitis suppurativa
- NHS: Hidradenitis suppurativa
- Hidradenitis Suppurativa Foundation: Patient resources