A keloid is a scar that keeps growing after the wound has already healed, spreading past the edge of the original injury. Keloids are not cancer, but they can itch, hurt and keep enlarging, and they are far more common on deeper skin tones. 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 an overgrown scar.
A keloid extends beyond the boundaries of the original skin injury.
It can persist.
Keloids can stay raised, itchy or painful long after the wound heals.
It is benign but stubborn.
Treatment can be difficult and recurrence is common.
Not every raised scar is a keloid.
Unusual or changing growths may need a biopsy.
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.
Keloid scar Grows past the wound edge; often returns.
Earlobe keloid A rounded scar grows around an ear-piercing site.
Hypertrophic scar Stays within the wound; may flatten.
Round lump Smooth and movable under skin.
Central opening A small dark pore on top.
Inflamed cyst Red, swollen and tender.
Scar-producing cells keep making collagen after a wound has closed. The resulting dense scar grows beyond the boundaries of the original injury.
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.
Keloids. Often arise in teenagers and younger adults after a skin injury, piercing or inflamed spot.
Epidermal Inclusion Cyst. Most often develops in adults, though it can occur at other ages.
Keloids form when the body makes too much collagen while healing a wound. The scar keeps growing past the original injury.
An epidermal inclusion cyst forms when surface skin cells get trapped under the skin and keep making keratin.
Keloids often run in families and are far more common in people with darker skin.
Evidence labels come from each condition’s own treatment list.
The best-supported thing you can buy for keloids without a prescription. Worn or applied over the scar for most of the day, over months, it softens and flattens it and eases the itch. It works best on new scars and on preventing one after a wound, and it will not clear a hard, old keloid on its own.
Clip-on discs that squeeze an earlobe keloid from both sides, used mainly after a keloid has been injected or removed. They have to be worn for many hours a day for months to cut the chance of it coming back. They are uncomfortable at first, and stopping early is the usual reason they fail.
Taping a fresh scar takes some of the pull off it while it is healing, which matters most on the chest and shoulders where tension keeps a keloid growing. It is used for the first few months after a wound closes. It is prevention rather than treatment, and it does nothing for a keloid that is already established.
Widely sold as a scar gel, and the studies behind it are small and mostly unconvincing for keloids. Some people find it makes the scar feel more comfortable, which is not nothing. If you are choosing one product to buy, silicone is the better use of the money.
Rubbing vitamin E oil on a keloid is one of the most common pieces of advice given, and it has not been shown to flatten one. In some people it also causes an itchy rash where it is applied. It is not a reason to delay treatment that works.
Clobetasol Propionate. A strong steroid ointment put on the keloid and covered overnight, usually to take the edge off itching between injection appointments. Covering it is what gets any of it through thick scar tissue. It will not flatten a keloid on its own, and long spells of use thin the normal skin around the scar.
A thin tape with steroid built into it, cut to the size of the scar and worn most of the day. It gives steady low-dose treatment plus a little pressure, and it suits small keloids and people who want to stretch the gap between injections. It is fiddly on hairy skin and can irritate the skin at the edges.
Triamcinolone Acetonide. The standard first treatment for a keloid: steroid injected directly into the scar, usually every four to six weeks. It calms the long-running inflammation and slows the cells making collagen, so itch and pain settle first and flattening follows over months. The main trade-off is a pale, thinned patch where it was given, which shows more on deeper skin tones.
A second medicine mixed with the steroid, or given on its own, when a keloid is stubborn or keeps returning. It targets the collagen-making cells directly, and combining it with triamcinolone works better than steroid alone in most studies. It stings more, and it can leave the surface sore or ulcerated for a short time.
Bleomycin injection. A chemotherapy drug used in tiny amounts inside the scar for keloids that have not responded to steroid and 5-fluorouracil. Small studies show it can flatten them. It is not widely offered, and dark spotting of the skin over the injection site is common, so it is a later option rather than an early one.
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.
A short course of low-dose radiation given within a day or two of removing a keloid, to stop the scar tissue rebuilding. For keloids that have already come back after surgery, it lowers the chance of another recurrence considerably. It is only available at some centers, and the long-term risks are discussed carefully before it is used, particularly in younger people.
Freezing can soften and flatten smaller keloids, and is sometimes used just before an injection to make the scar easier to inject. The problem is that freezing destroys pigment cells and often leaves a permanent white patch. On deeper skin tones, where most keloids occur, many dermatologists use it cautiously or not at all.
Cutting the keloid out works only as part of a plan. On its own it comes back in the large majority of cases, often bigger, so it is paired with injections at the time of surgery, pressure afterwards, or radiation. It is most useful for a big earlobe keloid or one that is limiting movement, where nothing else will get it flat.
A laser aimed at the blood vessels in the scar. It helps with the redness, and some people find it softer and less itchy afterwards, so it is used alongside injections rather than instead of them. It does not flatten a thick keloid, and settings have to be chosen carefully on deeper skin tones to avoid pigment change.
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.
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.
Keloids follow a slow pattern, and the first months are when treatment helps most. Nothing looks unusual early, so the change often arrives months after the wound closed.
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.
Coming back larger after surgery
A keloid cut out on its own comes back in most people, and often larger than the one that was removed, because the operation is another wound in the same high-risk skin. Surgery is still used, but as part of a plan with injections, pressure or radiation afterwards. If someone offers to simply cut it off, ask what will be done to stop it returning.
Itch, pain and tightness
Keloids frequently itch, sting or ache, and one sitting over a joint, the chest or an ear can feel tight and limit movement. For most people this, not the look of it, is the reason to get it treated. Itch and pain usually settle before the scar flattens, so treatment often feels worthwhile well before it looks it.
Pale, thinned skin after injections
Steroid injections can leave a pale, slightly sunken patch where they were given, and on deeper skin tones that lightening shows more and can last a long time. It often improves over months. Raise it before the first injection so the dose and technique are chosen with it in mind.
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 assessment for a growing, painful or itchy scar, or any lump whose diagnosis is uncertain. Discuss scarring risk before elective skin procedures.
Seek assessment if a lump is growing, recurrently inflamed or uncertain. Rapidly increasing pain, redness, drainage or fever may require prompt treatment.
Realistically, no. The goal is flat, soft and no longer itchy or painful, which leaves a flat mark rather than normal skin. Most improve a great deal; very few disappear.
It is a real risk worth discussing rather than deciding alone. Re-piercing through or next to a keloid often makes it bigger. If you go ahead, some dermatologists treat around the piercing preventively and add pressure earrings. Going back to the same studio with no plan is the version that goes badly.
Site matters as much as skin. The chest, shoulders, earlobes, jawline and back of the neck are high risk, partly because that skin is under constant tension and movement. The same injury heals flat on the leg and keloids on the sternum.
They sting, and a firm keloid makes it uncomfortable, but it takes seconds. Most people need several, usually every four to six weeks, and the number depends on size, site and how long it has been there. Itching and pain improve first, flattening later.
It can. A pale, slightly sunken patch at the injection site is a recognized side effect, more noticeable on deeper skin tones, and it often improves over months. Raise it before the first injection.
Tell the surgeon before the operation, not afterward. It changes where the incision goes, how it is closed, whether the wound is taped, and whether preventive injections are given. Ask what will be done differently because of your keloid history.
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.
Sources
