Disclosure: Vuret makes the HS Flare Control Cream featured on this page, so we have a financial interest in it. We still list real alternatives, including when another option may suit you better. This article is educational and is not a substitute for advice from your own doctor.
TL;DR
A skin cyst is usually a single, slow-growing, round lump that is painless unless inflamed. Hidradenitis suppurativa causes recurring, tender, inflamed lumps in skin folds, often with tunnels and scars. Many HS lumps are mistaken for cysts, so repeated "cysts" in the armpit or groin deserve a closer look.
Hidradenitis suppurativa vs cyst is a tough call at home because both can look like a firm lump under the skin. Doctors often see people who have been told for years that they keep getting cysts, when the real problem is HS. Here is how to sort out the difference.
Hidradenitis suppurativa vs cyst: the short answer
Verdict: a true cyst is usually a single, round, smooth lump that grows slowly and does not hurt until it gets inflamed or infected. HS lumps are tender from the start, show up in specific skin folds, come back repeatedly, and tend to leave scars or tunnels.
How do they compare side by side?
| Feature | Skin cyst (epidermoid or pilar) | Hidradenitis suppurativa |
|---|---|---|
| Typical look | Smooth, round, movable lump, sometimes with a central dot | Red, tender nodules, abscesses, open sores |
| Pain | Usually painless unless inflamed | Often painful, can be severe |
| Where | Face, scalp, neck, back, anywhere | Armpits, groin, buttocks, inner thighs, under breasts |
| Number | Often just one or a few | Multiple and recurring, often both sides |
| Growth | Slow, over months | Flare over days, then partly settle |
| Contents | Cheesy, thick material if opened | Pus, blood, fluid; can form tunnels |
| Scarring | Minor, unless removed or ruptured | Common, can be rope-like |
| Treatment | Leave alone, or surgical removal of the sac | Topicals, antibiotics, biologics, procedures |
What is a skin cyst?
An epidermoid cyst is a sac lined with skin cells that fills up with keratin. It can sit quietly for years. If it ruptures or gets infected, it becomes red, swollen and painful, which is when it starts to look more like HS.
Cysts typically have a small central opening (a punctum) and do not form tunnels with neighboring lumps.
What gives away HS?
- The location. Folds and friction areas, especially armpits, groin and inner thighs.
- The pattern. Lumps come back, often in the same place, and sometimes on both sides.
- Paired blackheads. Two openings side by side, a hallmark of HS.
- Scars and tunnels. Raised, rope-like scars or sores that keep draining.
- Pain. HS lumps hurt out of proportion to their size.
See our guides on armpit HS, groin and thigh HS, and HS vs boils.
How is each treated?
A cyst: if it is quiet, you can leave it. If it is annoying or inflamed, a doctor can inject it or remove the whole sac. Squeezing a cyst rarely removes it and often causes infection.
HS: treatment depends on severity. For mild to moderate disease, prescription topicals such as clindamycin and resorcinol are common starting points. Vuret's HS Flare Control Cream combines resorcinol 15% with clindamycin 1%, prescribed after an online physician review. It is compounded and not FDA-approved. Deeper disease may need oral antibiotics, a biologic, or surgery. See our ranking of HS treatments.
Why does the mix-up matter?
If you treat HS like a cyst, you may end up repeatedly lanced or surgically removed in the same area without addressing the underlying inflammation. That risks more scarring and a longer path to the right treatment.
On the flip side, if you have an ordinary cyst and try an HS regimen, you will not see much change, because a cyst has a sac that creams cannot dissolve.
Choose "cyst" if...
- It is one smooth, round lump that you have had for months.
- It is not painful unless irritated.
- It is on your face, scalp, neck, or back and not part of a recurring pattern.
Choose "think HS" if...
- You have a history of repeated painful lumps in folds.
- You see paired blackheads, tunnels, or scars.
- Lumps drain and return after "healing."
See a doctor in person for any lump that is growing quickly, hard and fixed to underlying tissue, bleeding, or accompanied by fever. A new lump that is changing should be examined rather than guessed at online.
Do HS lumps ever start as cysts?
Sometimes the line is blurry. An HS nodule starts as a blocked, inflamed follicle, and it can feel very much like an inflamed cyst. In long-standing HS, doctors may even find cyst-like structures lined with skin cells within old tunnels. This is why a doctor looks at the whole pattern over time rather than any one lump.
What tests might a doctor order?
Most of the time, none. HS is diagnosed by looking at the lesions, their location, and your history of recurrence. If the diagnosis is unclear, an ultrasound can show tunnels or a cyst sac, a swab can check for a bacterial infection, and in rare cases a biopsy is taken to rule out another condition. Blood tests are not used to diagnose HS, though your doctor may check them before starting certain medications.
What if surgery is on the table?
Removing a true cyst with its sac usually fixes it for good. Removing an HS lump alone often leads to new lumps nearby, because the underlying condition is still active. Surgery for HS is more extensive, targeting a whole area of disease, and it tends to work best alongside medical treatment. Ask your surgeon whether they treat HS regularly.
When should you not wait and see?
A harmless cyst can usually be watched. HS cannot. Each flare can leave a bit of scar tissue, and repeated flares can link together under the skin. If you have had two or more painful lumps in a fold within six months, get it looked at rather than waiting for the next one.
The same goes for any lump that is growing steadily, is fixed to deeper tissue, or appears in a place where you would not expect a cyst, such as a breast or the groin in someone over 50. Those should be examined in person.
What about other lookalikes?
Cysts are not the only imposter. Swollen lymph nodes in the armpit or groin can feel like a firm lump, and they often follow an infection or illness. Lipomas are soft, painless fatty lumps. Folliculitis causes clusters of small pimples around hair follicles. Each one has a different feel and a different cause.
That is why the pattern, location, and pain level matter. If you are unsure, a clinician can sort it out in a few minutes, and getting it right saves you from treatments that were never going to work.
If your lumps fit the HS pattern and are mild to moderate, you can start a private online visit on the Vuret HS page.
HS Flare Control Cream: Resorcinol 15% + Clindamycin 1%
A prescription cream that pairs resorcinol 15% with clindamycin 1%, applied right where flares start. Prescribed online by a U.S.-licensed physician only if it is right for you. Compounded medications are not FDA-approved.
See HS Flare Control CreamFrequently asked questions
Can HS be mistaken for a cyst?
Yes, quite often. Many people are told they have recurring cysts or boils for years before they receive an HS diagnosis.
Is a cyst in the armpit always HS?
No. A single smooth lump may be a true cyst or even a swollen lymph node. Repeated, painful lumps with drainage and scars point more toward HS.
Should I drain a cyst or HS lump at home?
No. Squeezing or cutting either one can cause infection, spread inflammation, and lead to scarring. See a clinician for drainage.
Do cysts turn into HS?
No, they are different conditions, though an inflamed cyst can look similar to an HS nodule.
How do doctors tell them apart?
By history, location, and exam. Sometimes ultrasound helps show tunnels or a cyst sac. A biopsy is rarely needed.