What are milia and what causes them?

Cynthia Bailey, MD|January 31, 2011

 Dermatologist Dr. Cynthia Bailey answers your questions about skin care and skin problems Dr. Bailey, I am 59 yrs old and prone to milia.  I also have sensitive skin, rosacea, and recently seborrhetic dermatitis (facial dandruff).  Would you please explain what causes milia, and the best way to prevent them. I suspect that I get more milia when I've been using suncreens w/ zinc.  Is this possible, or am I off-base? My best defense in the past has been Retin-A, but my skin has been more sensitive lately. Thank you, Susan Dear Susan, Milia are small cysts that are actually little pockets formed from your top skin layer called the epidermis.  They look like pinpoint hard white cysts, sometimes with a blackhead like opening to the skin surface.  When a person has a lot of them the skin takes on a cobbled appearance. The white material in a milium (single for milia) is made up of cells from the dead skin layer called the stratum corneum.  Unlike a sebaceous cyst (also called an epidermal inclusion cyst), milia do not form from a pore; they are just a pocket of normal skin that somehow indented, sealed over and the dead cells got trapped. Milia usually form spontaneously, not for any reason that we ever figure out.  They usually occur on the face, but I've seen them on the neck, scalp, chest, back and even the back of the hands.   Interestingly the changes in skin that happen from years of chronic sun damage seem to promote milia formation for predisposed people.  Milia also tend to occur after a rash or skin injury.  Rosacea and facial dandruff (seborrheic dermatitis) are rashes that can cause milia to form.  So are the rashes of allergic reactions and irritation from harsh products. Nothing absolutely prevents milia from forming if you're prone to them.  Typically we treat milia by keeping the skin exfoliated, but the exfoliation must be done without irritating the skin. Skin care products that create exfoliation like Retin A (tretinoin) and glycolic acid usually help reduce the size and number of milia.  Regular facials and mild chemical peels often help.  In my experience, using the Clarisonic Plus Sonic Brush or a Buf Puf Facial Sponge to gently cleans your skin can help too.  In my dermatology practice, I help patients utilize some combination of these options that doesn't irritate their skin because I find combination therapy the most effective means of controlling milia.

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Existing milia that don't respond to exfoliating skin care can be manually extracted in a medical office. The skin over the milia needs to be lanced with a sterile instrument and then the small deposit of dead skin can be gently extracted.  We use a tool called a comedone extractor to do this.  In my office this is a medical procedure because any puncture of the skin creates the risk of infections.  Also, the puncture and subsequent pressure with the comedone extractor creates a small wound, and as with any wound there is a very small chance of leaving a mark or scar afterwords. Susan, I was not able to find any medical reference connecting milia formation with zinc oxide sunscreen.  We know that sun damaged skin is prone to milia and so I actually think that makes zinc oxide sunscreen helpful for preventing milia in some sense.  I believe that micronized zinc oxide mineral sunscreens provide the best sun protection for the skin and are therefore important for preventing sun damage. Who know, using a zinc oxide sunscreen every day may ultimately reduce a person's lifetime risk of being a 'milia former'. Warm Regards, Cynthia Bailey MD, Dermatologist If you have questions about skin care or skin health please send them to me using the Contact Dr. Bailey button at the top of the page. Disclaimer: Please realize that availing yourself of the opportunity to submit and receive answers to your questions from Dr. Bailey does not confer a doctor/patient relationship with Dr. Bailey. The information provided by Dr. Bailey is general health information inspired by your question. It should not be a substitute for obtaining medical advice from your physician and is not intended to diagnose or treat any specific medical problem (and is not an extension of the care Dr. Bailey has provided in her office for existing patients of her practice). Never ignore your own doctor’s advice because of something you read here; this information is for general informational purpose only. If you found this helpful, you may also want to read: How To Unclog Your Clogged Pores Start The Best Anti Aging Skin Care Now and See Results In The New Year Facial Skin Care For Problem Skin With Facial Seborrhea, Rosacea and Clogged Pores Cracked, Dry, Brittle and Splitting Fingernails; Dermatologist's Tips