Closed Comedones vs Milia: How to Tell the Bumps Apart

Closed comedones vs milia: comedones are clogged pores that respond to salicylic acid and retinoids; milia are sealed keratin cysts that acids do not open.

By H. Lee · Research guide

Oct 7, 2026

Title card reading "Closed Comedones vs Milia: How to Tell the Bumps Apart" for the Acne marks & texture section of Korea Glow Report — Editorial hero image. Illustrative image.

Closed comedones and milia are both small white or skin-colored bumps, but they are different structures. A closed comedone (whitehead) is a pore plugged with oil and dead skin cells, and it responds to salicylic acid and retinoids. A milium is a tiny keratin cyst sealed under the skin; acids do not open it, and it should not be squeezed.

Key takeaways

Different structures: a closed comedone is a plug inside a hair follicle whose opening has closed; a milium is a walled cyst filled with keratin, the protein that makes up the outer skin layer (Berk and Bayliss, JAAD review, 2008).
Fastest tell: milia are pearly white, hard like a grain of sand, cluster around the eyes and upper cheeks and stay unchanged for weeks. Closed comedones are softer, skin-colored to white, gather on the forehead and chin and come and go with breakouts.
What works for comedones: the 2024 AAD acne guideline strongly recommends topical retinoids and conditionally recommends salicylic acid, which the FDA permits at 0.5% to 2% in over-the-counter acne products. Allow 6 to 8 weeks.
Milia are not a pore problem: exfoliating acids cannot dissolve a sealed cyst. Cleveland Clinic says adult milia often clear on their own within a few weeks to a couple of months and warns against squeezing them.
Check the lookalikes: in a 2022 study of 320 people diagnosed with acne, 28.8% had Malassezia folliculitis (fungal acne), which itches and favors the hairline and upper back.

What is the difference between closed comedones and milia?

The difference is where the material sits and whether it has an exit. A closed comedone is trapped oil and dead cells inside an existing pore, so ingredients that loosen the plug or normalize how the pore lining sheds can clear it. A milium is a separate, self-contained cyst just under the surface, so pore-clearing ingredients have no plug to work on.

That single distinction explains almost everything else: why the two feel different, why one comes and goes with your oil levels while the other sits unchanged for weeks, and why the bottle of BHA that cleared your forehead does nothing for the white dots under your eyes.

What are closed comedones?

A closed comedone is a hair follicle (pore) blocked with sebum, the skin’s oil, and corneocytes, the flattened dead cells that line the pore. The American Academy of Dermatology (AAD) describes it this way: “If the pore closes up, you’ll see a tiny bump that looks white or flesh colored. These are whiteheads.” When the opening stays wide, the top of the plug darkens on contact with air and the same lesion is called an open comedone, or blackhead.

Comedones are the non-inflamed form of acne. They start when the cells lining the follicle stick together instead of shedding, the opening narrows, and oil keeps arriving behind the blockage. They are most common where oil glands are dense: the forehead, chin, jawline and sometimes the cheeks. Because the plug sits in an active oil gland, closed comedones can turn red and inflamed, then settle, then return in the same zone. A cluster that thickens before your period or after a new heavy moisturizer is behaving like comedones.

“Clogged pores” is the umbrella term readers use for both blackheads and whiteheads. Closed comedones are simply the clogged pores you cannot see into.

What are milia?

Milia (singular: milium) are tiny cysts filled with keratin that form just beneath the outer layer of skin. Cleveland Clinic defines them as “small, white cysts on your skin” made of trapped dead skin cells that harden below the surface. A 2008 review and classification in the Journal of the American Academy of Dermatology by Berk and Bayliss divides them into two groups:

Primary milia form on their own. They are extremely common in babies: about 40% to 50% of US newborns have them, according to Cleveland Clinic, and they usually fade within weeks. Adults get them too, most often around the eyes, eyelids, nose and upper cheeks.
Secondary milia follow something that disturbs the skin: burns, blistering rashes, sun damage, resurfacing procedures, long-term steroid creams, or a reaction to a heavy skin cream or ointment.

Each milium has its own thin wall of skin cells, which is why it holds its round shape and pearly color. Some milia form from a hair follicle or sweat duct, but once the cyst forms it is closed off from the surface. Medications can play a role as well: a 2026 case report in Cureus described about 20 milia below the eyes of a 17-year-old two months into oral isotretinoin, cleared by simple manual extraction.

Closed comedones vs milia: side by side

Feature	Closed comedone (whitehead)	Milium
What it is	Oil and dead-cell plug inside a pore	Sealed cyst of keratin under the surface
Color	Skin-colored to dull white	Bright, pearly, porcelain white
Feel	Soft to slightly firm; flattens a little when stretched	Hard, like a grain of sand under the skin
Size	Varies, often uneven across a cluster	Pinhead-sized and uniform
Usual location	Forehead, chin, jawline, cheeks	Under and around the eyes, eyelids, nose, upper cheeks
Behavior over weeks	Comes and goes, can turn red and inflamed	Stays the same, rarely inflamed
Response to salicylic acid or a retinoid	Improves over 6 to 8 weeks	Little or no change from acids
Squeezing	Pushes debris deeper, raises inflammation (AAD)	Can scar or infect (Cleveland Clinic)

How can you tell them apart at home?

Use four checks in good light with clean hands: feel, color, location and behavior over time. One check rarely settles it; three pointing the same way usually does.

Feel. Run a fingertip over the bump. A milium feels distinctly hard and round, like a tiny bead. A closed comedone feels like a soft rise in the skin or a rough patch across a cluster.
Color. Stretch the skin gently between two fingers. A milium looks brighter white and almost reflective. A closed comedone looks flesh-toned or dull white, and the bump often flattens slightly under tension.
Location. White bumps on the eyelids or directly under the lower lashes are much more likely to be milia. Bumps scattered across the forehead and chin, especially in an oily zone, point toward comedones.
Behavior. Photograph the area in the same light once a week. Comedones change: some go red, some vanish, new ones appear. Milia look identical from photo to photo.

The most reliable home test is the response test. Use a leave-on salicylic acid or an adapalene gel consistently for 8 weeks on the area. Comedones thin out. Milia do not.

Closed comedones vs whiteheads, milia, keratosis pilaris and fungal acne

Four bumps are commonly mistaken for closed comedones. This cause-to-fix table puts them side by side.

Bump	What causes it	Key tells	First step with evidence
Closed comedone	Oil and dead cells plug a follicle whose opening closed	Skin-colored, forehead and chin, comes and goes	Topical retinoid or salicylic acid 0.5% to 2% for 6 to 8 weeks
Whitehead	Same lesion as a closed comedone (common name)	As above; a pus-filled bump is a pustule, not a comedone	Same as closed comedone
Milium	Sealed keratin cyst under the surface	Hard, pearly white, around eyes, unchanged for weeks	Lighter products near the eyes and time; professional extraction if it persists
Keratosis pilaris	Keratin plugs at follicle openings	Rough, sandpaper bumps on upper arms and thighs, sometimes cheeks	AAD lists moisturizers with urea or lactic acid, plus exfoliants such as salicylic acid
Fungal acne (Malassezia folliculitis)	Overgrowth of Malassezia yeast in follicles	Itchy, uniform small bumps on the hairline and upper back	Clinical diagnosis; acne routines alone often fall short

The fungal acne row deserves weight. In a 2022 study in Clinical, Cosmetic and Investigational Dermatology, researchers examined 320 new acne patients and found Malassezia folliculitis in 28.8%, mostly alongside ordinary acne. Itch made the yeast-driven condition 7.38 times more likely, and bumps on the scalp line and upper back raised the risk by about 9 times. Uniform, itchy bumps that ignore your acne routine are worth a closer look.

Why don’t acids work on milia, and why shouldn’t you pick them?

Acids fail on milia because there is nothing for them to reach. Salicylic acid is oil-soluble, so it moves into the oily pore channel and loosens the plug of cells. A milium has no channel to the surface; it is enclosed by its own wall, under intact skin. Surface exfoliants thin the top layer slightly but do not dissolve the keratin ball or its wall.

Retinoids are different from acids because they change how skin cells mature and shed over months. Cleveland Clinic lists adapalene gel or prescription tretinoin among options for milia, and published case reports describe tretinoin used for extensive forms. That makes a retinoid a reasonable long game for someone prone to recurring milia, but not a quick fix for one stubborn bump.

Picking is where milia do the most damage. A milium is hard and seated under intact skin, so squeezing does not move it; people end up digging with nails or pins. Cleveland Clinic is direct: “You shouldn’t try to squeeze or scrape off milia on your own, as you might do with a pimple. This can scar your skin or cause an infection.” The skin around the eyes is thin and marks easily. The AAD gives the same warning for comedones, noting that pushing contents “deeper into the skin” increases inflammation and can lead to scars.

Can heavy eye creams cause milia?

They can contribute, especially in people already prone to milia. Cleveland Clinic lists a reaction to “heavy skin cream or ointment” among the causes of secondary milia, and the area under the eyes is exactly where many people apply their richest product. The link comes from clinical observation, not controlled trials, so consider it a likely trigger to test rather than a certainty.

A practical way to test it: if new milia appear within a few months of starting a rich eye cream, balm or ointment, swap to a lighter gel-cream or lotion for the eye area for 8 weeks and keep everything else the same. Apply eye products to the orbital bone rather than packing them onto the lash line. Daily sunscreen matters here too, since Cleveland Clinic names sun exposure as another trigger.

What works for closed comedones?

Topical retinoids have the strongest evidence, followed by salicylic acid; benzoyl peroxide adds an antibacterial angle for comedones that keep turning into pimples. The AAD’s 2024 guidelines, built on a systematic review graded with the GRADE method, made strong recommendations for topical retinoids and benzoyl peroxide and conditional recommendations for salicylic acid and azelaic acid.

Retinoids. A retinoid is a vitamin A derivative that normalizes how pore-lining cells shed, which addresses the blockage itself. The AAD notes that adapalene is available without a prescription. In a 2006 investigator-blind maintenance trial of 253 people with severe acne who had already improved on 12 weeks of doxycycline-based treatment, adapalene 0.1% gel kept 75% at their improved level over 16 weeks, versus 54% on the vehicle gel, with significantly lower non-inflammatory (comedone) counts. Start every other night; dryness in the first weeks is common.

Salicylic acid. The FDA’s over-the-counter acne monograph (21 CFR 333.310, current as of 2026-10-05) allows salicylic acid at 0.5% to 2%. In a 2011 split-face trial of 20 people with comedonal acne, six salicylic acid peels at two-week intervals cut non-inflammatory lesions by 48.5% by day 98, similar to a lipohydroxy acid peel on the other side. At-home leave-ons are gentler than peels; in a 2023 randomized trial of 83 adults in Shanghai, a serum containing salicylic acid and lipohydroxy acid improved open comedones on the nose over 8 weeks, and adding a matching mask improved closed comedones more (minus 6.56 versus minus 5.19). Both groups used the acid serum, so there was no placebo arm, and the study was run by the manufacturer. Korean toners often use betaine salicylate instead; our COSRX BHA Blackhead Power Liquid formula breakdown converts its 4% betaine salicylate into salicylic acid terms.

Benzoyl peroxide. The AAD pairs a retinoid with a benzoyl peroxide wash for whiteheads.

Claim	Best evidence	Study type, size, duration	Strength
Topical retinoids reduce comedones	AAD acne guideline, 2024	Systematic review with GRADE recommendations	Guidance
Adapalene 0.1% keeps comedone counts down	Thiboutot et al., 2006	Randomized, vehicle-controlled maintenance after doxycycline, 253 people, 16 weeks	Moderate
Salicylic acid reduces comedones	Levesque et al., 2011; AAD guideline, 2024	Split-face randomized peel trial, 20 people, 98 days; conditional recommendation	Limited
Salicylic acid plus lipohydroxy acid leave-ons reduce closed comedones	Li et al., 2023	Randomized trial, 83 adults, 8 weeks, active comparator	Limited
Milia are walled cysts without a pore opening	Berk and Bayliss, 2008	Review	Limited
Heavy creams can contribute to milia	Cleveland Clinic list of secondary milia causes	Clinical observation summarized by Cleveland Clinic	Limited

If you start a retinoid or acid and see more small bumps in the first weeks, it is often purging, the accelerated surfacing of comedones already forming. Our guide on whether niacinamide causes purging explains how to tell a purge from a breakout. Milia do not purge; new white beads under the eyes are not a sign the routine is working.

A decision checklist for white bumps

Work down the list and stop at the first match.

Hard, pearly white, on the eyelids or under the lashes, unchanged for 3 or more weeks: likely milia. Switch to a lighter eye product, wear sunscreen and leave them alone.
Skin-colored or dull white, on the forehead, chin or jaw, some turn red at times: likely closed comedones. Start a retinoid or 0.5% to 2% salicylic acid and judge at 8 weeks.
Itchy, uniform bumps on the hairline or upper back: consider fungal acne before adding more acne actives.
Rough, gritty bumps on the upper arms or thighs: likely keratosis pilaris. Urea or lactic acid moisturizers come first.
Flat gray dots spread evenly across the nose: these are usually sebaceous filaments, not clogged pores; see our sebaceous filaments vs blackheads guide.

For milia that last beyond a couple of months, bumps that keep spreading or itching, or any bump you want extracted, a board-certified dermatologist can confirm what it is and remove it with sterile instruments.

Mistakes that make both worse

Scrubbing harder. Grainy scrubs do not reach a sealed milium and can irritate skin around comedones without clearing the plug.
Stacking acids on milia. Layering AHA, BHA and a peel pad under the eyes adds irritation to thin skin with no target to dissolve.
Judging a routine at week two. The AAD’s 6 to 8 week window exists because comedones form over weeks and clear over weeks.
Rich balms on comedone-prone zones. An occlusive night balm across the forehead and chin can keep feeding comedones while the actives work on them.
Needles, pins and nails. Both the AAD and Cleveland Clinic warn that home extraction risks infection and scarring.

Sources and research notes

AAD patient guidance on whiteheads, extraction and keratosis pilaris, the 2024 AAD acne guideline, the FDA OTC acne monograph, Cleveland Clinic guidance and a JAAD review classifying milia, case reports on milia, and peer-reviewed trials on adapalene and salicylic acid for comedones plus a prevalence study of Malassezia folliculitis, checked on the date shown.

Source record date: 2026-10-06. Prices and availability are as of that date.

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Frequently asked questions

Are closed comedones the same as whiteheads?

Yes. A whitehead is the everyday name for a closed comedone: a pore plugged with oil and dead skin cells whose opening has closed over, leaving a small white or skin-colored bump. People sometimes also call a pus-filled pimple a whitehead, but that is a pustule, an inflamed lesion.

Will salicylic acid get rid of milia?

Not directly. Salicylic acid loosens the plug inside an open follicle, while a milium is a keratin cyst with its own wall and no opening, so the acid has nothing to dissolve. Cleveland Clinic notes that adult milia often clear on their own within a few weeks to a couple of months.

Can eye cream cause milia?

It can contribute. Cleveland Clinic lists reactions to a heavy skin cream or ointment and long-term steroid creams among the causes of secondary milia. The evidence is clinical observation rather than controlled trials, so switching to a lighter eye product is a reasonable, low-cost step when new milia appear after starting a rich formula.

Is it fungal acne or closed comedones?

Itch and location are the main clues. In a 2022 study of 320 people diagnosed with acne, those with Malassezia folliculitis (fungal acne) were 7.38 times more likely to report itch, and the bumps clustered on the hairline and upper back; closed comedones rarely itch and sit mostly on the forehead and chin.

How long do closed comedones take to clear?

The American Academy of Dermatology advises giving a routine 6 to 8 weeks. Retinoids and acids can bring existing comedones to the surface in the first weeks, which is purging, so judge the result at the 8-week mark rather than week two.

Should I pop milia or closed comedones with a needle?

No. Cleveland Clinic warns that squeezing or scraping milia at home can scar the skin or cause an infection, and the AAD says pushing comedone contents deeper increases inflammation. Extraction with sterile instruments is a clinic procedure.