Skin Cysts
A round, smooth lump under the skin, filled with a cheesy keratin paste, often with a tiny dark pore on top. Usually harmless and slow-growing. Often called “sebaceous cysts”, though they mostly aren’t.
Common types. Epidermoid cysts grow on the face, neck, chest and back. Pilar cysts grow on the scalp, have no pore and often run in families. They can be pea-sized to several centimetres, and can become red, swollen and sore if they leak or get infected. Other lumps, such as lipomas (soft fatty lumps), ganglions near joints, and boils, can look similar.
Diagnosis is usually by feel and look. An ultrasound helps if the lump is unusual. On brown and black skin, removal scars are more likely to become raised and thick (keloids), worth weighing up before cosmetic removal.
The cyst ladder
If it’s not bothering you, leave it. Inflamed ones settle with time and sometimes drainage. Only full removal of the lining stops it coming back.
- Step 1 · Self-careLeave it aloneDon’t squeeze. Keep the area clean.
- Works
- Many stay small and quiet for years
- Cost
- Free
- How long
- Ongoing
- Watch for
- Growing fast, hard, fixed or over about 5 cm: get it checked.
Squeezing a cyst is how a quiet lodger becomes a noisy one.
- Step 2 · Self-careWarm compress for a sore, inflamed cystA warm, damp cloth for 10–15 minutes a few times a day, and simple pain relief.
- Works
- Not tested in trials; many inflamed cysts settle over a week or two
- Cost
- Free to about $10
- How long
- Days to 2 weeks
- Watch for
- Spreading redness, fever or severe pain: see a doctor.
Patience and a flannel. Unexciting, often effective.
- Step 3 · GPDraining, and sometimes antibioticsA doctor can lance a cyst that has become a pus-filled abscess. Antibiotics are used when infection is spreading.
- Works
- Gives quick relief; not tested in trials and the cyst often comes back later
- Cost
- Often bulk-billed or about $40–150 out of pocket
- How long
- One visit, then dressings for a few days
- Watch for
- Many red cysts are inflamed rather than infected, so antibiotics don’t always help.
Pressure relief now, proper removal later.
- Step 4 · ProcedureRemoval of the whole cystCut out under local anaesthetic once it’s calm, including the lining (sac).
- Works
- Not tested against other options in trials; removing the whole sac is the best way to stop it coming back
- Cost
- GP: about $100–300 out of pocket; often private if cosmetic
- How long
- One procedure; stitches out in 1–2 weeks
- Watch for
- A scar longer than the lump; raised scars are more likely on brown and black skin. Best done when it isn’t inflamed.
Leave even a scrap of sac and it may move back in.
Save your money
Popular, heavily marketed or often asked about, but the evidence is weak or says no.
- Squeezing or poppingSpreads the contents under the skin, causing inflammation, infection and a bigger scar.
- DIY lancing with a needleInfection risk, and the cyst comes back because the sac is still there.
- Drawing ointments and “cyst dissolving” creamsNo good trials. A cyst’s lining doesn’t dissolve.
- Antibiotics for every red cystMany are inflamed, not infected, and settle without them.
What you can do
- Leave it alone unless it bothers you.
- For a sore one, use a warm compress and simple pain relief.
- If you want it removed, wait until it’s calm: surgery on an inflamed cyst is messier and it’s more likely to return.
See your GP if
- You’re not sure what the lump is
- It’s red, sore, swollen or leaking
- It grows quickly, feels hard or fixed, or is over about 5 cm
- It keeps flaring and you’d like it removed
- You find a new lump in the breast, testicle, neck or groin (these always need a check)
See a doctor the same day for a red, hot, very painful lump with fever, spreading redness, or feeling unwell.
Common questions
Is a skin cyst cancer?
Almost never. Cysts are harmless. A lump that grows fast, feels hard or is stuck down should be checked to make sure it’s a cyst.
Why does it smell?
The cheesy contents are keratin and skin oils. The smell is normal and isn’t a sign of infection on its own.
Will it go away on its own?
Some shrink after leaking, but most stay and can flare again. Removing the whole sac is the only permanent fix.
Are they contagious?
No. You can’t catch or spread skin cysts.
Helpful resources
- NHS 111 Wales: Skin cystPlain guide to types, what to avoid and when to see a GP. Free, UK.
Evidence and more information
maladywise.com/skin-cysts/