Syringoma: Causes, How to Tell It From Milia, and Treatment With CO2 Laser or Electrocautery
Syringoma, called “sio hin” (stone acne) in Thai, is a small benign tumor of the sweat duct in the dermis. It is not acne and is not caused by clogged pores. It looks like firm, skin-colored or pale yellow bumps 1–3 millimeters wide that appear in symmetrical clusters, most often on the lower eyelids and under the eyes.
Because syringoma sits deep in the dermis and has no whitehead or oil inside, it cannot be squeezed out, does not shrink with acne creams, and rarely goes away on its own. Treatment that works means having a doctor destroy the bumps, for example with a carbon dioxide laser or electrocautery. This article explains how to recognize each type of syringoma, how to tell it apart from milia, clogged pores and xanthelasma, the risks of each treatment, and when to see a doctor.
What is syringoma, and how is it different from ordinary acne?
The term “sio hin” is what most people call the small firm bumps on the face when they assume it is a kind of acne. Medically, it is syringoma, a tumor of the duct part of the sweat gland (eccrine duct) in which the duct overgrows and is surrounded by firm fibrous tissue in the dermis. Under a microscope, small tadpole-shaped or comma-shaped ducts can be seen lined up.
The main differences from ordinary acne are as follows.
Where it starts: Acne starts in the hair follicle and oil gland, while syringoma starts in the sweat duct.
What is inside: Acne is plugged with oil and keratin, so it can be pressed or squeezed out. Syringoma is solid tissue with nothing to squeeze out.
Inflammation: Acne can be red, swollen and pus-filled. Syringoma is almost never inflamed.
Duration: Acne comes and goes within days to weeks. Syringoma stays for years and usually increases in number slowly.
Response to acne treatment: Benzoyl peroxide, salicylic acid and antibiotics do not make syringoma shrink.
What does syringoma look like? How to check at home
Features that suggest syringoma include the following.
Small raised bumps 1–3 millimeters wide with a smooth surface and a flat or slightly domed top
The same color as the skin, pale yellow, or light brown in darker skin tones
Firm to the touch, as if a grain of sand were embedded under the skin
Usually several bumps, from a few to dozens, appearing equally on both sides
No whitehead or blackhead and no central opening
Not painful or itchy, except for some types such as genital syringoma, which may itch in hot weather or around menstruation
Some people notice the bumps more in hot weather, when sweating heavily, or after exercise, because the sweat ducts swell
The most common locations, in order, are the lower eyelids and under the eyes, the upper eyelids, and the upper cheeks, followed by the neck, chest, abdomen, armpits and genitals.
What causes syringoma, and who is at risk?
It is still not clear exactly why some sweat duct cells multiply too much. Factors often found together with it include the following.
Female sex: It is clearly more common in women than in men. Hormones are believed to play a role, because some people find the bumps more noticeable during pregnancy or menstruation.
Age: It usually begins in the teenage years after puberty and increases most between the ages of 20 and 40.
Ethnicity: It is common in Asian people, including Thai people.
Genetics: Some families have several affected members, inherited in a dominant pattern.
Down syndrome: Syringoma is found several times more often than in the general population. Some studies report it in about 1 in 5 patients.
Diabetes: It is linked with the clear-cell type of syringoma.
Certain connective tissue disorders such as Marfan syndrome and Ehlers-Danlos syndrome are occasionally found together with it.
Things that are not causes of syringoma include not washing the face well, clogging creams or cosmetics, oily food, cow's milk, and staying up late. These beliefs lead many people to spend months changing their skincare while the bumps stay the same.
Syringoma under and around the eyes (localized type, the most common)
Appearance: Skin-colored or pale yellow bumps 1–3 mm wide lined up on both lower eyelids. In some people they spread to the upper eyelids and upper cheeks. When there are many, they can merge into a raised, rough patch that makes the under-eye area look thick and shiny.
Cause: Sweat ducts around the eyelids multiply too much. It usually starts in the late teens and slowly increases in number during working-age years.
Severity and urgency: It is not dangerous and does not turn into cancer. It is mainly a cosmetic concern, and there is no need to treat it urgently.
When to see a doctor: When you want it removed, because the skin around the eyes is very thin, so the bumps must be treated close to the eyeball, which requires eye shields and a skilled doctor. Also see a doctor if a single bump grows quickly, forms a sore, or bleeds.
Eruptive syringoma on the neck, chest and back
Appearance: Many skin-colored, light pink or brown bumps, from dozens to hundreds, appearing together in crops on the front of the neck, chest, abdomen, armpits and sometimes the back. It is often mistaken for acne, folliculitis or an allergic rash. In darker skin the bumps may be darker than the surrounding skin.
Cause: It occurs in teenagers and young adults. Some people have a family history, and some also have Down syndrome. It is thought to be a reaction of the sweat ducts to inflammation rather than a true tumor.
Severity and urgency: It is not dangerous, but it is widespread, so treating each bump one at a time is difficult, and there is a risk of dark marks or scars on the chest, where raised scars form easily.
When to see a doctor: When bumps spread quickly for no known reason, because it must be told apart from other rashes that are treated differently, such as lichen planus, eruptive xanthoma linked to very high blood fats, or flat warts. The doctor often needs to take a small skin sample from 1 spot to confirm.
Genital syringoma (genital and vulvar syringoma)
Appearance: Several small skin-colored or brown bumps on both outer labia, or less often on the skin of the penis. Unlike syringoma on the face, it often itches, especially in the hot season, around menstruation, or during pregnancy.
Cause: The same as syringoma in other locations. Some people also have syringoma around the eyes.
Severity and urgency: It is not a sexually transmitted infection and does not spread to a partner, but it can look like genital warts and other genital bumps, so it should not be self-diagnosed.
When to see a doctor: Every time a new bump appears on the genitals, to tell it apart from genital warts, molluscum contagiosum, blocked apocrine sweat glands (Fox-Fordyce disease), and lichen simplex from scratching. If the itch is severe, the doctor may prescribe a short course of anti-inflammatory cream along with an antihistamine.
Clear-cell syringoma in people with diabetes
Appearance: It looks like ordinary syringoma and may appear on the eyelids or spread over the body. The difference is seen on skin biopsy, which shows cells filled with glycogen so they look clear.
Cause: It is clearly linked with diabetes. It is believed to involve glycogen building up in cells when blood sugar stays high for a long time.
Severity and urgency: The bumps themselves are not dangerous, but they are a sign that blood sugar should be checked. Some patients first learn they have diabetes from this biopsy result.
When to see a doctor: When the biopsy report shows the clear-cell type, you should have a fasting blood sugar and an HbA1c test if you have not had one within the past year.
Syringoma in children and in people with Down syndrome
Appearance: Small white bumps on a young child's face are mostly not syringoma but milia, which affect about half of newborns and clear on their own within 2–4 weeks. True syringoma usually starts in children who have already reached puberty.
Cause: When syringoma is found in a child before the teenage years, there is usually an associated factor: family history, eruptive syringoma, or Down syndrome, in which syringoma tends to appear earlier and in larger numbers.
Severity and urgency: It is not harmful to health. In children, watching and waiting is usually recommended over procedures, because cautery or laser in children needs anesthesia and a lot of cooperation.
When to see a doctor: When you are unsure whether it is milia or syringoma, when bumps spread over the body, or when the child also has delayed development. A pediatrician or dermatologist should assess it.
How is syringoma different from milia, clogged pores, xanthelasma and other bumps?
Several conditions cause small bumps under the eyes and on the face that look alike. Basic ways to tell them apart are as follows.
Syringoma: Firm skin-colored or pale yellow bumps 1–3 mm wide, several in number, symmetrical, with no head, cannot be squeezed out, and do not go away on their own.
Milia: Round pearly white bumps 1–2 mm wide that sit more superficially and show clearly as white dots under thin skin. A doctor can open the skin with a needle and press the keratin bead out. For more detail, read What causes milia, and why can't they be squeezed like acne?
Closed comedone: Small skin-colored bumps on the forehead, chin and cheeks. Stretching the skin shows a white dot in the center, they usually occur with other types of acne, and they respond to retinoid creams within 8–12 weeks. See more on telling them apart at What causes clogged pores, and how to tell open from closed comedones.
Xanthelasma: Clearly yellow, raised flat plaques, usually at the inner corner of the eye, much larger than syringoma bumps. Blood fats should always be checked.
Sebaceous hyperplasia: Yellow bumps with a dimple in the center, 2–5 mm wide, found on the forehead and nose of adults aged 40 and over. See more at Sebaceous hyperplasia, the yellow bumps on the face.
Flat wart: Flat skin-colored or light brown bumps, often arranged in lines along scratch marks. It is contagious and increases in number faster.
Trichoepithelioma: Skin-colored bumps around the nose and the cheek folds, often with a family history. A biopsy is needed to tell it apart.
When several types of bump appear together, the doctor uses a skin magnifier (dermoscope) to help look, and takes a biopsy if still unsure.
Can syringoma go away on its own, and why can't it be squeezed out?
Syringoma rarely falls off or goes away on its own. Most bumps stay for life and may slowly increase in number between ages 20 and 40. In some people the bumps may become slightly smaller after menopause, but you should not wait in hope of that.
The reason it cannot be squeezed out is that syringoma lies in the dermis about 0.5–1 millimeter below the surface and is solid tissue, not a sac holding fluid or oil. Squeezing, picking or poking with a needle only causes scrapes, bleeding, dark marks and, in some people, pitted scars, while the bump stays where it was.
Is syringoma dangerous? Can it turn into cancer?
Syringoma is a benign tumor. It does not turn into cancer, is not contagious, and does not affect physical health. The main effect is on confidence and appearance.
However, some bumps look like syringoma and need further testing, including the following.
Basal cell carcinoma: Usually a single bump with a shiny, pearly surface and tiny blood vessels on top that keeps growing and may become a sore that does not heal within 4 weeks.
Microcystic adnexal carcinoma: Very rare. Usually a single firm plaque on the upper lip or cheek that slowly spreads deeper. Under the microscope it can resemble syringoma if the biopsy is too shallow.
Signs to see a doctor promptly: A single bump that is clearly growing faster than the others, is larger than 5 mm, is firm and plaque-like, is fixed to the tissue beneath, forms a sore, bleeds on its own, or makes the skin in that area numb.
How do doctors diagnose syringoma?
When the bumps appear in symmetrical clusters on the lower eyelids in the classic pattern, a dermatologist can often diagnose syringoma by looking and feeling. Additional steps that may be used include the following.
Taking a history: Age at onset, increase in number, itching, underlying conditions such as diabetes, and family history.
Dermoscopy: Helps tell apart milia, sebaceous hyperplasia and basal cell carcinoma, which have different vessel patterns.
Punch biopsy of 2–3 mm: Done when bumps are spread over the trunk, appear on the genitals, are a single unusual bump, or do not respond to treatment as expected. Biopsy results take about 5–7 working days.
Blood tests: Blood sugar when the biopsy shows the clear-cell type, and blood fats when xanthelasma or eruptive xanthoma is suspected.
Treating syringoma with a carbon dioxide (CO2) laser
The carbon dioxide laser, with a wavelength of 10,600 nanometers, is the method dermatologists use most often for syringoma on the face. The laser energy is absorbed by water in the tissue and precisely vaporizes the bump's tissue layer by layer.
How it is done: Numbing cream is applied for about 45–60 minutes, or local anesthetic is injected. Metal eye shields are placed when working near the eyelids. The doctor fires the laser in spots directly on each bump. Some techniques make several tiny holes in a single bump to reduce heat buildup and the chance of scarring.
Recovery: Small scabs form and fall off on their own in 5–7 days. The new skin stays pink-red for 2–4 weeks, or longer in some people.
Number of sessions: Usually 1–3 sessions, 6–8 weeks apart. Larger or deeper bumps may need more.
Realistic expectations: Bumps flatten or disappear to different degrees in different people. Destroying deeply enough to remove the entire sweat duct comes at the cost of a higher risk of scarring, so doctors often work gradually over several sessions.
For an overview of the different skin lasers, read What can each type of skin laser treat?
Treating with electrocautery and excision
Electrocautery (electrodesiccation or electrocautery): The doctor uses a very fine needle tip to deliver low-energy electric current into each bump so that it dries out and falls off as a scab within 5–7 days. Results are similar to the carbon dioxide laser when done by an experienced doctor. It suits a small number of bumps and usually also needs to be repeated 2–3 times. For more on electrocautery, see Electrocautery to remove skin tags, moles and skin bumps.
Surgical excision: Suitable when there are only 1–2 bumps, or when a sample needs to be sent for testing at the same time. The advantage is that it removes the bump to its full depth. The disadvantage is that stitches are needed and a fine line scar remains, so it is not suitable for many bumps.
Methods dermatologists usually avoid around the eyes: Cryotherapy (freezing) and high-concentration trichloroacetic acid (TCA), because the depth is hard to control and there is a higher risk of white patches or scarring in Asian skin.
How much can creams and pills help syringoma?
No cream or pill has been reliably shown to make syringoma disappear, because the bumps are tissue in the dermis that medicine cannot reach. Most of the available information comes from a small number of case reports.
Tretinoin cream 0.025–0.1% at bedtime: There are reports that it flattens eruptive syringoma on the trunk somewhat with continuous use for 3–6 months. It is not recommended on the eyelids because they are easily irritated. It must not be used during pregnancy.
Oral isotretinoin: Only occasional reports exist in eruptive syringoma. It is not a standard treatment and has many side effects, for example pregnancy must be strictly avoided during use and for 1 month after stopping.
Very itchy genital syringoma: The doctor may prescribe a low to medium strength steroid cream such as triamcinolone acetonide 0.1% once or twice a day for no more than 2 weeks, together with a non-drowsy antihistamine such as cetirizine 10 mg once a day to control itching. This helps the itch but does not make the bumps go away.
Ordinary acne medicines: Benzoyl peroxide, salicylic acid, azelaic acid and antibiotics do not work on syringoma.
The measure of whether a medicine is working is the number and height of the bumps after 3 months of continuous use. If nothing changes, it should not be continued indefinitely, and you should return to discuss options for destroying the bumps. The choice of medicine, its strength and how long to use it are decisions for the examining doctor.
Risks, side effects and recurrence
Every method of destroying syringoma carries risks, which should be understood before deciding.
Post-inflammatory hyperpigmentation: Common in Asian skin. It usually fades on its own within 3–6 months with good sun protection.
Lighter skin or white patches: Less common, but in some people it lasts a long time.
Pitted or raised scars: The risk is higher with deeper treatment, with picking at scabs, or when treating the chest and shoulders.
Prolonged redness: In some people the redness lasts more than 4 weeks.
Wound infection: Uncommon when the wound is cared for correctly.
Lower eyelid pulled down (ectropion): Very rare. It occurs when a large amount of lower eyelid tissue is destroyed at the same time.
Recurrence: Parts of the sweat duct deeper than the treated spot can grow back over months to years, and new bumps may appear in other places. This is the nature of the condition, not a mistake in treatment.
Results vary from person to person, depending on the number and depth of the bumps, skin color and aftercare.
Aftercare following laser or electrocautery for syringoma
First 24 hours: Apply a cold compress through a clean cloth for 10 minutes at a time to reduce swelling, especially around the eyes.
Cleaning the wound: Rinse gently with saline or clean water once or twice a day, pat dry, then apply the ointment the doctor prescribed, such as a thin layer of petroleum jelly to keep the wound moist.
Do not pick the scabs: Let them fall off on their own in 5–7 days. Picking increases the chance of dark marks and scars.
Avoid makeup on the wound until all scabs have fallen off.
Strict sun protection: Use sunscreen SPF 30 or higher and wear a hat or sunglasses for at least 4–8 weeks.
Avoid exfoliating acids and retinoids on the area for about 1–2 weeks, or as your doctor advises.
Return to the doctor right away if the wound becomes more swollen and red, more painful, has pus, or you have a fever.
What not to do yourself at home
Squeezing, picking or poking with a needle: Syringoma has no head and cannot be squeezed out. You only get wounds and dark marks.
Using mole-removal pens or cautery devices sold online: The depth cannot be controlled, and there is a risk of burns, scars and eye injury.
Dabbing on strong acids or wart-removal products yourself: The skin around the eyes is very thin, with a risk of deep wounds and scars.
Applying steroid cream to the face continuously for a long time: It does not shrink syringoma but thins the skin, dilates blood vessels and causes a rash around the mouth.
Keep changing skincare or buying acne creams: Syringoma is not caused by clogging, so it does not respond to these products.
When to see a dermatologist, and how to prepare
See a dermatologist when
You are not sure whether the bumps are syringoma, milia, clogged pores or another condition
You want the bumps removed, especially around the eyes
Bumps spread quickly on the neck, chest or trunk
You have bumps on the genitals or severe itching
You have a single bump that grows quickly, forms a sore or bleeds
You have diabetes, or syringoma together with symptoms of another underlying condition
Preparing before your visit: Take photos of the bumps to compare changes, write down all medicines and creams you are using, and tell the doctor if you have a history of raised scars, cold sores on the lips, pregnancy, or use of blood thinners. If you plan to have a procedure on the same day, avoid makeup on the area to be treated and allow about 1 hour for the numbing cream.
Quick summary
Syringoma is a benign tumor of the sweat duct. It is not acne and is not caused by clogging.
It appears as firm skin-colored bumps 1–3 mm wide, several in number, symmetrical, most often under the eyes. It is more common in women and Asian people.
It cannot be squeezed out, does not go away on its own, is not helped by acne medicines, and does not turn into cancer.
It can be told apart from milia, clogged pores, xanthelasma and sebaceous hyperplasia by location, color and dermoscopy.
Treatment that works is destruction of the bumps by a doctor with a carbon dioxide laser or electrocautery. It usually needs 1–3 sessions, and it can recur.
Bumps on the genitals, bumps that spread quickly, or a single bump that grows quickly should be examined by a doctor to confirm.
Frequently asked questions about syringoma
I have syringoma. How is it treated?
The treatment that works for syringoma is destruction of the bumps by a dermatologist. The methods used most often are the carbon dioxide laser and electrocautery with a very fine needle tip, done after numbing cream has been applied for about 45–60 minutes. Small scabs form and fall off on their own in 5–7 days. Usually 1–3 sessions are needed, 6–8 weeks apart. If there are only 1–2 bumps, they may be cut out and stitched. Creams and pills do not make syringoma go away, and squeezing or cauterizing it yourself at home risks scars and dark marks. The doctor chooses the method according to the number, location and depth of the bumps and each person's skin color.
Can syringoma go away on its own?
Syringoma rarely falls off or goes away on its own, because it is a benign tumor of the sweat duct lying about 0.5–1 millimeter deep in the dermis, not oil or keratin plugging a pore, so there is no head to come out. Most bumps stay for years and usually increase in number slowly between ages 20 and 40. In some people the bumps become slightly smaller after menopause. If you see small white bumps that come out on their own when pressed, they are more likely milia than syringoma. If you want the bumps gone, have a dermatologist assess them and destroy them the right way.
How is syringoma different from milia?
Syringoma is a tumor of the sweat duct, while milia are tiny keratin cysts lying superficially under the skin. Syringoma is firm, skin-colored or pale yellow bumps 1–3 mm wide, several in number and symmetrical under the eyes, that cannot be squeezed out and do not go away. Milia are clearly round pearly white beads 1–2 mm wide, which a doctor can open with a needle and press out in one visit, and in babies they usually clear on their own in 2–4 weeks. The treatments therefore differ: milia are pressed out, while syringoma needs a laser or electrocautery. If you cannot tell them apart, the doctor will use a dermoscope to help look.
What causes syringoma in children?
Small white bumps on a child's face are mostly not syringoma but milia, which affect about half of newborns and go away on their own. True syringoma usually starts when a child reaches the teenage years, because it is related to hormones. When syringoma is found in a young child before the teenage years, there is usually an associated factor, such as a parent or sibling with the same thing, eruptive syringoma appearing in crops on the neck and chest, or Down syndrome, in which syringoma is found several times more often than in other children. Syringoma in children is not dangerous. Doctors mostly recommend watching first, and a doctor should confirm that it really is syringoma.
How is syringoma under the eyes treated?
Syringoma under the eyes can be treated with a carbon dioxide laser or electrocautery, one bump at a time. The dermatologist places metal eye shields to protect the eyes during the procedure. The eyelid skin is very thin, so doctors usually treat superficially and split the treatment into 2–3 sessions, 6–8 weeks apart, to reduce the risk of scarring, dark marks and a lower eyelid pulled down. Afterward there is mild swelling for 1–3 days, scabs fall off in 5–7 days, and you must use sunscreen and wear sunglasses for at least 4–8 weeks. You should not use freezing, acid dabbing or a mole-removal pen yourself under the eyes.
Do natural remedies for syringoma work?
No natural method has been shown to make syringoma shrink or disappear, whether face masks, natural oils, herbal creams, aloe vera or massaging under the eyes, because the bumps are solid tissue in the dermis that products applied to the skin cannot reach. What you can do yourself is not squeeze or pick at it, protect against sun so the marks around the bumps do not darken, and cover it with concealer if the look bothers you. Removing the bumps needs a procedure by a doctor. A caution: recipes using lemon, acids or garlic on the skin can burn the skin around the eyes and cause scars.
The information in this article is general knowledge to help you decide whether to see a doctor. It is not a diagnosis or a prescription for any individual. The choice of treatment, medicine, dose and duration of use must always be assessed by a doctor.
Warning: Laser or electrocautery to remove syringoma carries a risk of not working as expected, and may cause harm or side effects such as dark marks, scars or recurrence. Results vary from person to person. It should always be assessed and performed by a doctor.
To read about other bumps and skin conditions written by our dermatologists, visit the skin conditions article hub.
Written by Dr. Patara Voravutinon, Dermatologist · Last reviewed October 1, 2026
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