Hidradenitis suppurativa is a long-term inflammatory condition that causes painful lumps, abscesses and tunnels in the armpits, groin and under the breasts. It is not an infection and it is not caused by poor hygiene, and treating it early is what prevents the scarring. An epidermoid cyst is a firm lump under the skin, lined with the same cells as the skin surface and slowly filling with keratin. It is harmless and often sits quietly for years. The trouble starts when the wall ruptures, which is why squeezing one is the worst thing you can do to it.
The same eight facts on every condition comparison.
It is a chronic inflammatory disease.
It causes recurrent painful nodules, draining tunnels and scars, usually in skin folds.
It is not contagious.
It is not caused by poor hygiene.
Early recognition matters.
Prompt diagnosis can reduce treatment delays and limit tissue damage.
The whole picture guides care.
Pain, drainage, activity limits and mood all shape the treatment plan.
It is a keratin-filled sac.
The cyst is a usually benign sac lined by skin-like cells and filled with keratin.
It grows slowly.
It often appears as a slowly growing lump with a central opening.
"Sebaceous cyst" is a misnomer.
It is commonly called a sebaceous cyst, but its contents are not simply trapped oil.
Unusual lumps need examining.
A new, changing, hard, fixed or uncertain lump should be checked rather than assumed to be a cyst.
Hurley stage I Single lumps, no tunnels or scars.
Hurley stage II Recurring lumps with tunnels and scars.
Hurley stage III Widespread tunnels and scarring.
Round lump Smooth and movable under skin.
Central opening A small dark pore on top.
Inflamed cyst Red, swollen and tender.
Blocked hair follicles can widen and rupture, releasing contents into nearby tissue and triggering painful inflammation. Repeated episodes may lead to tunnels beneath the skin and scarring.
A sac lined by skin-like cells forms beneath the surface and fills with shed keratin. If the lining ruptures, escaped keratin can provoke inflammation in the surrounding tissue.
Hidradenitis Suppurativa. Usually begins after puberty, often in the teens or younger adult years.
Epidermal Inclusion Cyst. Most often develops in adults, though it can occur at other ages.
Hidradenitis suppurativa starts with blocked hair follicles in skin folds. The immune system then overreacts, causing deep, painful lumps.
An epidermal inclusion cyst forms when surface skin cells get trapped under the skin and keep making keratin.
About 1 in 3 people with it have a relative with it.
Evidence labels come from each condition’s own treatment list.
An antiseptic wash used two or three times a week on the affected folds, lathered and rinsed rather than left on. It lowers the bacteria on the skin and is often paired with clindamycin lotion to stop resistance building. It will not stop lumps forming on its own, and it bleaches towels and dark clothing.
For flare pain, which is at its worst in the day or two before a lump bursts or is drained. Taken regularly through a flare they work better than taken only at the peak. If they are not touching the pain, that is a reason to be seen rather than to take more, because a steroid injection settles a single lump far faster.
An alternative antiseptic wash for the folds if benzoyl peroxide is too drying or bleaches too much. Same use: lather, rinse, a few times a week. It reduces the odor some people find hardest to live with. It does nothing about the inflammation underneath, so it is a support rather than a treatment.
Oral zinc is often suggested online for this condition. The studies behind it are small and uncontrolled, and it has not been shown to change flares in any reliable way. High doses upset the stomach and interfere with copper absorption over time. Worth mentioning to your doctor rather than starting alone.
Not a treatment, but the thing that changes daily life most for anyone with a draining lesion. A soft absorbent pad held with tubular netting or a stretchy vest handles the fluid without an adhesive that tears sore skin. A dermatology nurse can advise which dressing suits which site, and many are available on prescription.
A twice-daily antibiotic lotion for mild disease, the one topical here with real trial evidence behind it. It reduces the number of lumps and abscesses, and in early disease works about as well as tetracycline tablets. It is nearly always paired with a benzoyl peroxide wash, because clindamycin used alone breeds resistant bacteria.
Resorcinol 15% cream. A peeling cream dabbed on a building lump to help it open and settle faster, made up by a compounding pharmacy. Some people find it shortens a flare noticeably. It stings, it can leave a temporary dark stain on deeper skin tones, and it only goes on the lump itself, not across the whole fold.
A tetracycline antibiotic taken for two to three months, used here for its anti-inflammatory effect rather than to kill an infection. That is why the course is months rather than a week. It reduces flares for many people with mild to moderate disease, and it generally stops working once it is stopped. Take it with water and stay upright afterwards, and expect to burn more easily in the sun.
Two antibiotics taken together for a set ten to twelve week course in moderate disease, usually when tetracyclines have not held. The combination works better than either alone. Rifampicin turns urine and tears orange, stains soft contact lenses, and interferes with several medicines including the contraceptive pill, so the doctor needs your full medicine list.
A hormonal tablet that suits people whose flares track the menstrual cycle. The evidence is from clinics rather than large trials, but the response in the right person can be very good. It takes three to six months to judge, it raises potassium so blood tests are needed, and it must not be used in pregnancy.
A combined pill can reduce flares that cluster before periods, and it is often used alongside spironolactone rather than instead of it. Progesterone-only methods sometimes make the condition worse. Smoking matters here in two ways: it worsens the disease and it also rules out the combined pill for many people over 35.
A diabetes tablet sometimes added where there is insulin resistance, polycystic ovary syndrome or metabolic syndrome alongside the skin disease. Small studies show fewer flares in that group. It is an add-on, not a main treatment, and it commonly upsets the stomach for the first few weeks.
A short course of steroid tablets to break a severe flare while a longer-term treatment is being arranged. It works quickly. It is not a way to manage this condition, because flares return as the dose comes down and repeated courses cause weight gain, bone loss and blood sugar problems.
Isotretinoin transforms severe acne, so it is a fair question here. It works much less well for this condition, which starts in the follicle but is not driven by oil, and many people are no better on it. Acitretin, a related tablet, has slightly better results. Neither can be used in pregnancy.
The first biologic licensed for this condition, given as a self-injection under the skin every week or two. It blocks one of the immune signals driving the disease and reduces lumps and abscesses in moderate to severe cases. It does not close existing tunnels. You are screened for tuberculosis and hepatitis first, and infections need reporting while you are on it.
A newer biologic injection that blocks a different immune signal, licensed for this condition after trials in moderate to severe disease. It is the usual next step when adalimumab has not worked or has stopped working. Like adalimumab, it treats the inflammation rather than the tunnels, so it is often combined with surgery.
A small amount of steroid injected straight into a single painful lump, which usually settles it within a day or two. It is the fastest thing available for one bad flare and it avoids cutting. It treats that one lump only, and repeated injections in the same spot can thin the skin, so it is not a plan on its own.
A small injection of steroid into an inflamed cyst early in a flare, which settles the swelling and pain over a few days. It is for the flare, not the cyst — the sac and its lining are still there afterwards. It works best in the first day or two, before the lump has come to a head.
The roof of a tunnel is removed under local anesthetic and the floor is left to heal open. The tunnel does not come back in that spot. It is small, done in clinic, and leaves a flatter result than cutting a wide block of skin out, which matters more on deeper skin tones. It treats the tunnels you have, not the disease, so medication usually continues.
Wide excision. A whole affected area is removed surgically, for advanced disease where tunnels run right across an armpit or groin. Disease does not return in the removed area, though it can appear at the edges or in another fold. It is done in an operating theatre, healing takes weeks, and the area may need a skin graft or flap.
Removing the hair removes the follicle that plugs, and several courses of treatment reduce flares in early disease. It works best on Hurley stage one and two, before tunnels form. On deeper skin tones the device matters: the long-pulsed Nd:YAG is the usual choice, and the wrong laser causes burns and pigment change. Ask which one the clinic will use.
Incision and drainage. Cutting a swollen abscess open relieves severe pressure and pain quickly, which is why it is done in emergency departments. It does not change the course of the condition and the lump usually refills in the same place within weeks. Repeated draining of the same spot encourages a tunnel to form, so it is a rescue measure rather than treatment.
Incision and drainage. A small cut to let out the contents of a large, painful, inflamed cyst. The relief is immediate and it is exactly the right thing to do for an abscess. It is not a cure: the lining stays behind and keeps making keratin, so it usually refills over weeks to months. The usual plan is to settle things this way, then remove the sac properly a month or two later.
The only thing that ends a cyst, because it takes out the sac wall as well as the contents. It is a single minor procedure under local anesthetic, done through a small cut that is usually placed along a natural skin crease. Done on a quiet cyst it lifts out whole and leaves a thin line; done on an inflamed one it tears, fragments get left behind, and it is more likely to come back.
It runs in flares and quiet periods, and follows a longer arc over years. Not everyone progresses. The toll is real — pain, drainage, dressings, clothes chosen around it, embarrassment about the smell — and rates of depression and anxiety are high, worth raising at an appointment.
Left alone, a cyst sits quietly for years, punctuated by flares. The pattern matters more than any single episode - a cyst that has never flared can come out whenever it suits you, while one that has flared twice is on a trajectory. Plan removal during a quiet spell.
Scarring and restricted movement
Years of flares in the same fold leave thick, rope-like scars that pull the skin tight. In an armpit that can limit how far the arm lifts; in the groin it can make sitting or walking uncomfortable. Scars cannot be reversed with medication, so the way to avoid them is to get on proper treatment early. Surgery can release or remove a badly scarred area.
Depression and anxiety
Constant pain, drainage, dressings and the smell wear people down, and rates of depression and anxiety in this condition are high. It is a normal response to a hard illness, not a separate weakness. It is also rarely asked about, so it is worth raising yourself at an appointment. Getting the skin under control usually helps a great deal, and support for the mood side can be arranged at the same time.
Squamous Cell Carcinoma
A rare complication of very long-standing disease, usually after decades of tunnels and scarring on the buttocks or groin. A skin cancer can grow in the damaged skin. The warning sign is a lump, ulcer or growth that behaves differently from your usual flares and does not settle. Anything like that should be looked at and biopsied rather than treated as another flare.
Rupture and a painful flare
The wall tears and keratin spills into the tissue around it, and the immune system attacks it. The lump becomes hot, swollen and painful over a day or two, and feels bigger and firmer than it did. Most of these are not infections. Squeezing is the single most common reason it happens, so leaving a quiet cyst alone is the best prevention there is.
Infection or an abscess
Sometimes bacteria do get in, and the cyst becomes a genuine abscess. It looks much like an ordinary flare, so the things that point to infection are spreading discoloration, pus, fever and feeling unwell. This is the version where antibiotics belong, and a large abscess usually needs draining as well. A hot, inflamed cyst around the nose, eyes or upper lip is treated more cautiously than one anywhere else.
Scars and keloids from repeat flares
Every rupture and every emergency drainage lays down its own scar, and after a few episodes the area is tethered and marked before anyone has operated. Raised, thickened scars and keloids are more likely on the chest, shoulders, upper back and jawline, and more likely on deeper skin tones. A planned removal on a quiet cyst usually leaves a thin line along a natural skin crease, which is the argument for doing it sooner.
Seek early assessment for recurring painful lumps, drainage or tunnels. Fever, spreading redness or severe pain needs prompt care.
Seek assessment if a lump is growing, recurrently inflamed or uncertain. Rapidly increasing pain, redness, drainage or fever may require prompt treatment.
No. It cannot be passed through skin contact, towels, swimming pools or sex. It starts in your own hair follicles and is driven by your own immune system.
They were never killing an infection. Tetracyclines are given for months here because they calm inflammation, and the effect fades when they stop. If antibiotics are not holding, move up to hormonal treatment or a biologic.
Only if tunnels have formed, and not everyone reaches that stage. Medication treats inflammation but cannot close a tunnel, so once one exists a small procedure called deroofing is often the cleanest answer. It is done under local anesthetic and the tunnel does not return.
It helps, and it does not fix it. Losing weight reduces friction, reduces affected folds and lowers background inflammation, and many notice fewer flares. But people of every size get this, and treating it as a weight problem is one reason people are sent away without proper treatment.
Shaving and waxing tend to provoke flares, so clipping is better day to day. Laser hair removal often reduces flares by removing the follicle and is worth considering, particularly in early disease. On deeper skin tones the device matters — ask which laser will be used.
The condition does not affect fertility, but several treatments are not suitable in pregnancy, including some antibiotics and hormonal treatments. Many find it flares in pregnancy and improves afterwards, or the reverse. Plan ahead with the doctor managing your pregnancy, and never start or stop a medicine on your own.
Epidermoid cysts are benign. They do not spread and do not turn into cancer. Cancers arising inside a cyst are described but genuinely rare. Have it examined if it grows rapidly, feels hard and fixed rather than mobile, bleeds, or has a sore over it that will not heal - those suggest the lump may not be a cyst.
The contents are keratin and broken-down skin cells, sealed in for a long time, and skin bacteria break that material down. The smell comes from the contents, not from infection.
You can, and for a large, painful, inflamed cyst that is the right thing for relief. But draining empties the contents and leaves the lining, and the lining makes keratin, so it refills over weeks to months. Removing the whole sac is what ends it.
Because the result is worse. Inflamed tissue is swollen and fragile, so the sac tears instead of lifting out whole, fragments get left behind, the cyst is more likely to come back, and the scar is wider. Settle the flare first, then remove it a month or two later.
Not if the whole lining comes out, which is the goal. Recurrence happens when a fragment is left behind, more likely if the cyst was inflamed or heavily scarred from previous flares. New cysts can form elsewhere - that is a new cyst, not the old one.
Not reliably, because most people who get one have no identifiable cause. You can reduce flares - do not squeeze them, take pressure and friction off them, and treat significant acne if cysts keep appearing where it was. If you are getting a lot from a young age, mention it, because a few people have an inherited reason.
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