Small White Spots on Skin That Don't Itch: What Causes Them? A Dermatologist Separates IGH, Pityriasis Versicolor, Pityriasis Alba and Vitiligo
Small white spots on the skin are medically called hypopigmented macules, meaning areas of skin that have less melanin than the surrounding skin, so they show up as white or paler-than-normal spots or patches. It is not a single disease but a sign shared by several conditions. The six most common groups of causes are idiopathic guttate hypomelanosis (IGH), pityriasis versicolor, pityriasis alba, vitiligo, post-inflammatory hypopigmentation, and whitening from scars or steroids. White patches that are numb or have reduced sensation to touch are a sign of leprosy and must always be examined.
Most people who search for “small white spots on the skin” do not yet know what they have, and often start by buying an antifungal cream because they think it is pityriasis versicolor. In the dermatology clinic, however, small white spots on the shins and arms of adults aged 30 and over are most often IGH, which is not a fungus and needs no cream at all. This article helps you tell the causes apart using what you can see yourself: size, scale, itch, location, age and spread. It then explains which ones clear up on their own, which need treatment, and which need to see a doctor promptly.
What small white spots on the skin tell you: the 6 most common causes
Skin colour comes from the pigment melanin, which is made by pigment cells (melanocytes) and passed to the surrounding skin cells. Skin looks paler than normal when one of three things happens: the pigment cells work less for a while (for example after inflammation, or when disturbed by yeast), the pigment cells decrease in number with age and sun exposure (IGH), or the pigment cells are destroyed completely (vitiligo). So how white the spot is gives a first clue. A spot that is “paler than the skin” and a patch that is “milk-white” come from different mechanisms.
IGH Small round white spots, 2–5 millimetres, with a clear edge and smooth surface, on the shins and arms of people aged 30–40 and over. The most common type in adults. Harmless and does not spread.
Pityriasis versicolor White or brown patches with fine, powdery scale on the back, chest, neck and shoulders. Caused by yeast on the skin. Common in teenagers and working-age adults who sweat a lot.
Pityriasis alba Faint white patches with unclear edges and fine scale on the cheeks of children aged 3–16. Linked to dry skin and atopic skin. Not a fungus.
Vitiligo Milk-white patches with a clear edge, no scale and no itch, slowly enlarging and often appearing symmetrically on both sides. Hair within the patch may turn white.
Post-inflammatory hypopigmentation Paler skin where there used to be a rash, acne, a wound or an insect bite. A temporary mark that regains its colour on its own.
Whitening from scars or steroids Old scars with smooth, shiny skin, or thin white patches with visible blood vessels after steroid creams or injections.
Warning sign: numb white patches Pale patches with reduced sensation, dry skin and no sweating are an early sign of leprosy and must always be examined by a doctor.
Comparing the 6 causes: size, scale, itch, location, age and spread
Go through these six points one by one against your own patches. Most of the time the answer narrows down to one or two causes.
IGH Size: 2–5 mm, not more than 1 cm · Scale: none, smooth surface · Itch: none · Location: shins, forearms, upper arms, upper back · Age: 30 and over · Spread: separate spots that do not merge into patches, number increases slowly with age
Pityriasis versicolor Size: 0.5–1 cm, merging into patches several cm wide · Scale: fine scale, clearly visible when lightly scraped · Itch: none or slight when sweating · Location: back, chest, neck, shoulders, upper arms · Age: teens to 35 · Spread: can enlarge and merge, more obvious in summer
Pityriasis alba Size: 0.5–5 cm · Scale: fine, dry skin · Itch: none or slight · Location: cheeks, around the mouth, chin, upper arms · Age: 3–16 years · Spread: 1–20 patches, not enlarging quickly, more obvious after sun exposure
Vitiligo Size: from a few mm to patches several cm wide · Scale: none, smooth surface · Itch: none · Location: around the eyes, around the mouth, fingers, wrists, elbows, knees, ankles, genitals · Age: any age, half begin before age 20 · Spread: slowly enlarging, merging, often symmetrical on both sides
Post-inflammatory hypopigmentation Size: same as the original rash · Scale: none, unless the original rash is still present · Itch: none · Location: where there was a rash, acne, a wound or an insect bite · Age: any age · Spread: does not spread, fades within 3–6 months
Scars and steroids Size: same as the wound or the area where the cream was applied · Scale: none, surface smooth and shiny or thin · Itch: none · Location: old scars, injection sites, or where steroid cream was applied for a long time · Age: any age · Spread: does not spread, scars are permanent, drug-related marks gradually regain colour
Numb white patches (leprosy) Size: patches larger than 1 cm, often several cm · Scale: none, but dry skin with no sweating and hair loss · Itch: none, but numb · Location: arms, legs, buttocks, back, face · Age: any age · Spread: gradually increasing in number, together with numbness of the hands and feet
IGH: small white spots on the arms and legs of people aged 30 and over
Appearance White round or oval spots 2–5 millimetres across; some may grow to 1 centimetre but no larger. Porcelain-white, with a clear edge and a surface level with the surrounding skin, no scale, no itch and no pain. They are scattered as separate spots that do not merge into patches. The most common site is the shins, followed by the outer forearms and upper arms. Some people get them on the upper back and chest, but they almost never appear on the face. The number of spots slowly increases over several years. Spots that have appeared usually stay for good and do not regain colour by themselves.
Cause Not clearly known, which is why the name includes the word idiopathic. The evidence points to accumulated sun exposure and age, since the spots appear only on areas that are regularly exposed to the sun. On biopsy, the pigment cells in the spot are fewer and less active, together with genetic factors. Studies in several countries have found IGH in more than half of people aged 40 and over, and in about 8 out of 10 older adults. In a tropical country like Thailand, where skin is exposed to the sun all year, it can appear as early as the early 30s.
Urgency Not urgent. IGH is not cancer, is not contagious, does not turn into vitiligo and has no effect on health. It is a cosmetic matter only and does not need treatment. What you can actually do is use sunscreen and cover the skin to slow the appearance of new spots. Cosmetic procedures, such as short-term cryotherapy or certain topical medicines, give unpredictable results and the spots may return; a doctor will consider these case by case.
When to see a doctor Spots larger than 1 centimetre, several spots joining into a patch, unclear edges or scale, spots on the face, around the mouth or on the hands, or spots appearing quickly in someone under 30, because these features are not typical of IGH and it needs to be distinguished from vitiligo.
Pityriasis versicolor: pale patches with fine scale on the back, chest and neck
Appearance It starts as round or oval spots 0.5–1 centimetre across, then merges into larger patches several centimetres wide. The colour can be pale white, pink or light brown, which is why it is called versicolor, meaning many colours. The key point is fine, powdery scale: when lightly scraped with a fingernail, the scale lifts off and the patch becomes more obvious. There is no itch, or only slight itch when sweating. It appears on the back, chest, neck, shoulders and upper arms, which are areas with many oil glands. It is common in teenagers and working-age adults aged 15–35, and is more obvious in summer or after sun exposure because the surrounding skin tans while the patches do not.
Cause The yeast Malassezia, which normally lives on everyone's skin, multiplies abnormally in hot, humid weather, with heavy sweating, oily skin, or tight, damp clothing. The yeast produces fatty acids that inhibit pigment production, so the skin there becomes paler. Pityriasis versicolor is not passed from person to person, because everyone already carries this yeast; the difference lies in skin conditions that allow it to grow.
Urgency Not dangerous. It can be treated with topical antifungal medicine or medicated shampoo, but it recurs very often. It has been reported to come back in about 60% of people within 1 year and 80% within 2 years if not prevented. A common worry for patients is that the fungus has cleared after treatment but the patches are still white, which is normal. Pigment needs 1–3 months or longer to return to the same shade as the surrounding skin. For more on telling it apart and preventing recurrence, read Pityriasis versicolor: what causes it, how a dermatologist tells it from vitiligo and ringworm, and how to keep it from coming back
When to see a doctor The scale has not cleared or the patches keep enlarging after 2–4 weeks of antifungal cream, the area is larger than several palms, it recurs more than 2–3 times a year, or patches on the back and abdomen have no scale at all and do not respond to antifungal medicine, because it may be a look-alike condition called progressive macular hypomelanosis, which is related to bacteria in the hair follicles rather than yeast and needs different treatment.
Pityriasis alba: faint white patches on a child's cheeks, not a fungus
Appearance Round or oval patches 0.5–5 centimetres across, mostly 1–4 centimetres, pale white rather than bright white. The edges are unclear and blend into the surrounding skin. The skin is dry with very fine scale. Some children start with faint pink patches that go unnoticed before fading to white. The most common site is the cheeks, followed by around the mouth, chin, forehead, upper arms and trunk. There may be anywhere from 1 to 20 patches, in children aged 3–16, and parents often notice them in summer because the surrounding skin tans from the sun while the patches do not.
Cause A very mild skin inflammation in children with dry skin or atopic skin, together with triggers such as sun, harsh soap and scrubbing in the bath. The inflammation temporarily reduces how much pigment the pigment cells pass to the skin. It is not a fungus, not a worm infection, not contagious, and has nothing to do with drinking milk. The Thai name, which literally refers to milk, is a folk name that has misled people for generations. Many children with pityriasis alba also have a history of atopic dermatitis.
Urgency Not urgent. It clears on its own over several months to 2–3 years, and mostly clears before the teenage years without leaving a mark. The main care is moisturiser twice a day, sunscreen, and avoiding harsh soap. A doctor may give a mild anti-inflammatory cream for a short period if the skin is very dry and red. For details, read Pityriasis alba: what causes it, why it is not a fungus, and how to bring the skin colour back
When to see a doctor Patches that are milk-white with sharp, crisp edges, enlarge quickly within a few weeks, appear on the hands, around the eyes or on the genitals, have been present since birth, or are numb to touch, because these need to be distinguished from vitiligo, congenital white birthmarks and leprosy.
Vitiligo: milk-white patches with a clear edge that slowly enlarge
Appearance Milk-white or chalk-white, because there is no pigment left at all in that area. The edge is very sharp and sometimes darker than normal skin. It starts as small spots of a few millimetres and enlarges into patches several centimetres wide. The surface is smooth with no scale, no itch and no pain. Favourite sites are around the eyes, around the mouth, fingers, wrists, elbows, knees, ankles, armpits and genitals, including areas of friction or earlier injury. The most common type appears symmetrically on both sides of the body. Hair within the patch may turn white. It can begin at any age; about half begin before age 20. It affects roughly 0.5–2% of the population.
Cause The body's immune system destroys its own pigment cells, together with genetic factors. Some patients have relatives with the same disease. Common triggers are sunburn, injury, friction, stress and certain chemicals. Vitiligo is not contagious, and autoimmune thyroid disease occurs together with it more often than in the general population, so a doctor may order a thyroid blood test in some patients.
Urgency Not an emergency, but it is the only cause in this group where starting treatment early makes a clear difference compared with treating late. Patches that appeared within the first few months, and patches on the face and neck, respond better than patches present for many years or on the hands and feet. Treatment ranges from anti-inflammatory creams and topical immune-modulating creams to medical light therapy at a healthcare facility, which must be continued for several months. For details, read Vitiligo: what causes it and how is it treated
When to see a doctor As soon as you suspect it, especially milk-white patches with a sharp edge that enlarge within a few weeks, patches appearing similarly on both sides, white hair within a patch, or a family member with vitiligo. Waiting several months to see what happens wastes the period when the disease responds best to treatment.
Post-inflammatory hypopigmentation
Appearance Patches paler than the skin but not bright white, shaped like the original rash or wound, with unclear edges and a smooth surface, with no scale unless the original rash has not fully cleared. Found where there was atopic dermatitis, contact dermatitis, psoriasis, seborrhoeic dermatitis around the nose folds and eyebrows, acne, insect bites, scrapes, burns or scalds, or after a skin procedure. It is more obvious in people with darker skin than in those with fair skin.
Cause Inflammation temporarily disrupts pigment production and the transfer of pigment from the pigment cells to the skin cells. Once the inflammation settles, the system gradually returns to normal.
Urgency Not urgent. Most regain their colour on their own within 3–6 months, and some take up to 12 months. What actually helps is calming the underlying rash, applying sunscreen so the surrounding skin does not tan and make the mark more obvious, and not scrubbing the mark. If the underlying cause damaged the skin deeply, such as a deep burn, the mark may be permanent and become a white scar.
When to see a doctor The underlying rash keeps flaring up, the mark has not regained any colour in 6 months, you cannot remember having a rash beforehand, or there are several white patches on the trunk that have not cleared with cream and have lasted for years, because in the last case the doctor may need a biopsy to tell it apart from a less common but important skin disease.
Whitening from scars and from steroids
Appearance A white scar sits on an old wound, with smooth, shiny or sunken skin, no hair follicles or hair, and does not extend beyond the wound. Whitening from steroids occurs in 2 ways. The first is white patches where a high-potency steroid cream was applied continuously for a long time, especially on the face, skin folds and in children; the skin becomes thin enough to show small blood vessels. The second is white marks around steroid injection sites, such as injections for keloids or inflamed acne, appearing 2–6 weeks after the injection. In some people it forms a long white line extending from the injection point along the lymphatic path.
Cause Steroids suppress the pigment cells and thin the skin. The stronger the drug, the longer it is used, or the more it is applied under a dressing, the more easily this happens. Ready-made combination creams that put a steroid, an antifungal and an antibiotic in one tube are the most common cause the clinic sees, because people buy them to put on every kind of patch without knowing a strong steroid is inside.
Urgency Not urgent. White marks from injections usually regain colour on their own in 6–12 months, and marks from creams gradually improve after stopping the drug, but thin skin and small blood vessels may last longer. A white scar is permanent; all that can be done is to make it blend in better with the surrounding skin.
When to see a doctor If you have used steroid creams that you bought yourself, including combination creams, continuously for more than 2 weeks and the skin begins to thin, turn white or show blood vessels, have a doctor assess it and adjust the medicine, because stopping a strong drug suddenly after long use can make the original rash flare back.
Numb white patches with no sensation are a sign of leprosy and must always be examined
Appearance Patches paler than the skin or reddish, not bright white like vitiligo, with unclear edges, usually larger than 1 centimetre. The skin in the patch is dry, does not sweat and has lost hair, and most importantly it is numb or has reduced sensation when tested with cotton wool, a needle tip, or something warm and cold. There may be one patch or several on the arms, legs, buttocks, back or face. Symptoms that often come together are numbness of the fingers and toes, weakness of the hands and feet, or enlarged, tender nerves that can be felt at the elbows and behind the knees. The disease progresses very slowly, with an average incubation period of 5 years and sometimes up to 20 years.
Cause The bacterium Mycobacterium leprae, spread by prolonged close contact with an untreated patient, through droplets from the nose and mouth. It is very hard to catch: more than 95% of people have natural immunity, and patients who have been on medicine for only a few days no longer pass on the infection. Thailand still finds new cases every year, and most come to a doctor late because they thought it was ordinary pityriasis versicolor or vitiligo.
Urgency Needs to be examined promptly, not because the germ is dangerous, but because the disease can be completely cured with a combination of several antibiotics (multidrug therapy) for 6–12 months, which is available in Thailand's public health system, and early treatment is the only thing that prevents permanent disability of the hands, feet and eyes caused by nerve damage.
When to see a doctor White or red patches that do not clear with any cream and are numb to touch, or numbness of the fingers and toes, weak hands or feet, or enlarged nerves: go to a hospital or dermatology clinic without waiting. The examination is just a sensation test and a skin scraping for germs, it does not hurt, and there is no reason to feel embarrassed.
Small white spots on the legs
The shin is the number one site for IGH. If you are an adult aged 30 or over, with spots no larger than 5 millimetres, with a clear edge, no scale and no itch, scattered over both shins, the chance of IGH is very high and no cream is needed. White patches on the legs that are not IGH usually look like this.
A round white mark where a mosquito or insect bite was scratched is post-inflammatory hypopigmentation. Common in children, and it regains colour on its own in 3–6 months.
Milk-white patches with a clear edge on the knees, ankles or tops of the feet, especially when they appear similarly on both sides, should make you think of vitiligo.
Smooth, shiny white marks along old wounds are scars.
Large pale patches that are numb and do not sweat on the legs or buttocks need to be checked for leprosy.
Pityriasis versicolor rarely appears on the legs. If the white patches on the legs have no scale, buying an antifungal cream to apply is almost useless.
Small white spots on the arms
The outer forearms and upper arms are the second most common site for IGH, after the shins. The same rule applies: spots smaller than 5 millimetres, with a clear edge and no scale, in adults whose arms are regularly in the sun. The arms are also a place where several conditions overlap.
Pale patches on the outer upper arm with fine scale and rough skin in teenagers and working-age adults are usually pityriasis versicolor spreading from the shoulders. Lightly scrape and you will see the scale.
Several faint white patches with unclear edges on a child's upper arm are pityriasis alba appearing outside the face.
Milk-white patches with a clear edge on the elbows, wrists and backs of the hands should make you think of vitiligo, because these are favourite sites for it.
Pale patches on the outer arm that are numb and dry need to be checked for leprosy.
Small white spots on the face
The face is a place where IGH almost never appears, so white spots on an adult's face deserve more attention than white spots on the arms or legs. The common causes by age group are as follows.
Faint white patches with unclear edges and dry skin on a child's cheeks are pityriasis alba, the most common cause in school-age children.
Pale scaly patches on the forehead, temples and hairline in teenagers with oily skin may be pityriasis versicolor of the face, which occurs in tropical countries.
Pale marks in the nose folds, between the eyebrows and beside the nose after a red, flaking rash has cleared are post-inflammatory hypopigmentation from seborrhoeic dermatitis, and usually clear on their own once the rash is controlled.
Milk-white patches with a clear edge around the eyes, around the mouth or on the chin should always make you think of vitiligo first. These are also sites that respond better to treatment than the hands and feet, so it is even more important to see a doctor early.
Thin white patches with visible small blood vessels where a cream is regularly applied are marks from a cream containing a steroid, or from a whitening cream containing a banned ingredient.
Small white spots on the back and trunk
The back and chest are the territory of pityriasis versicolor. Multicoloured patches with fine scale, merging into patches over the middle of the back, chest and shoulders in people who sweat a lot, are the picture doctors see most often. But 4 other conditions appear in the same places.
White patches on the middle of the back and abdomen with no scale at all that do not improve with antifungal medicine in teenagers and young adults may be progressive macular hypomelanosis, which is related to bacteria in the hair follicles and needs different treatment from pityriasis versicolor.
Small white spots scattered on the upper back in older adults are IGH appearing outside the arms and legs.
Milk-white patches with a clear edge on both sides of the trunk looking alike should make you think of vitiligo.
Large pale patches on the back or buttocks that are numb, dry and do not sweat need to be checked for leprosy.
White patches on your child's skin: how children differ from adults
In children, IGH is almost never seen. The number one cause becomes pityriasis alba and post-inflammatory hypopigmentation, both of which are linked to dry skin, atopic skin and scratching, not to a fungus or worms.
Pityriasis alba Faint white patches with unclear edges on the cheeks, ages 3–16. Clears on its own over several months to 2–3 years. Care with moisturiser and sunscreen.
Post-inflammatory hypopigmentation White marks where there was atopic eczema, nappy rash, blisters or a scratched insect bite. Regains colour in 3–6 months.
Pityriasis versicolor Seen more in teenagers than in young children, but in tropical countries young children can get it on the forehead and cheeks. Look for the fine scale.
Congenital white birthmark (nevus depigmentosus) A single pale patch present from birth or within the first year, of constant size and growing with the child. Does not spread and needs no treatment, but a doctor should confirm it once.
Three or more leaf-shaped white patches in an infant need to be examined, because they may be a skin sign of a genetic condition involving the brain and internal organs, where early detection is very important.
Vitiligo Half of patients begin before age 20. Milk-white patches with a clear edge around a child's eyes, around the mouth or on the hands, and a white ring forming around a mole, should be seen by a dermatologist early.
Leprosy in children It can occur in children living in the same household as an untreated patient. A pale patch that is numb is the same sign as in adults.
A rule that applies to every child: white patches with unclear edges and fine scale are usually not worrying, while patches that are bright white, sharp-edged, quickly enlarging or numb must always be examined.
A doctor can tell them apart in a few minutes with a Wood's lamp and KOH
Telling most white patches apart needs no blood test or biopsy. There are 3 main tools in the examination room, and together they take no more than a few minutes.
Wood's lamp is a long-wave ultraviolet light viewed in a dark room, taking about 2 minutes. Vitiligo glows bright bluish-white with a sharp edge. IGH also glows white but in small spots. Some pityriasis versicolor glows golden-yellow or pale orange. Progressive macular hypomelanosis glows red along the hair follicles. Pityriasis alba and post-inflammatory hypopigmentation simply become slightly more visible without any specific glow.
Skin scraping with KOH solution The doctor scrapes scale from the skin, adds a drop of potassium hydroxide solution and looks under the microscope. It takes about 5–10 minutes. In pityriasis versicolor, short threads and clusters of yeast spores are seen. In IGH, pityriasis alba, vitiligo or post-inflammatory hypopigmentation, the result is negative.
Sensation testing Using a light touch of cotton wool, the point of a blunt needle, and tubes of warm and cold water, comparing inside the patch with normal skin. It takes less than 1 minute. If sensation inside the patch is reduced, the doctor goes on to check for leprosy with a skin scraping for germs and by feeling the nerves.
A biopsy is needed only when the results above conflict, or for white patches on the trunk that have lasted for years and do not respond to any treatment.
How does treatment differ for each one?
The right treatment depends on the cause. There is no single cream that works for every type of white patch, and a medicine that suits one condition may make another worse.
IGH Needs no treatment. Use sunscreen and cover the skin to reduce new spots. Cosmetic procedures give unpredictable results; a doctor considers them case by case.
Pityriasis versicolor Topical antifungal medicine or a medicated shampoo left on before rinsing, of the type and duration set by the doctor or pharmacist, generally 2–4 weeks. For widespread or frequently recurring cases, the doctor may give oral medicine. After the yeast has cleared, allow 1–3 months for the colour to return, and use the medicated shampoo periodically in summer to prevent recurrence.
Pityriasis alba Moisturiser twice a day, sunscreen and mild soap. A doctor may give a mild anti-inflammatory cream for a short time only in children whose skin is very dry and red.
Vitiligo Anti-inflammatory cream according to the doctor's plan, topical immune-modulating cream for the face and skin folds, and medical light therapy at a healthcare facility 2–3 times a week continuously for several months. Response is assessed every 3–6 months. In stable cases that are not spreading, there may be a surgical option of pigment cell transplantation at a hospital.
Post-inflammatory hypopigmentation Treat the underlying rash, use sunscreen, then wait 3–6 months.
Whitening from steroids Stop or adjust the medicine under the doctor's guidance. The marks gradually regain colour in 6–12 months.
Leprosy A combination of several antibiotics for 6–12 months through the public health system, together with nerve care and prevention of disability.
Important The type and strength of every medicine above must be set by a doctor or pharmacist. This article explains the principles so that you understand why each type of white patch needs different treatment; it is not a recipe for buying medicine to use on your own.
What clears on its own and what does not
Clears on its own Post-inflammatory hypopigmentation (3–6 months, up to 12 months in some), pityriasis alba (several months to 2–3 years, usually clearing before the teenage years), and white marks from steroid injections (6–12 months).
Clears once the yeast is treated, then wait for the colour to return Pityriasis versicolor. The scale clears within 2–4 weeks of starting medicine, but the colour returns more slowly, 1–3 months later, and it can recur if not prevented.
Does not clear on its own but is not dangerous IGH, where spots that have appeared stay permanently, white scars, and congenital white birthmarks.
Does not clear on its own and should be treated early Vitiligo, which very rarely regains colour without treatment, and leprosy, which can be completely cured but only with medicine.
Creams people often buy by mistake
Antifungal cream applied to every kind of white patch works only for pityriasis versicolor. It has no effect on IGH, pityriasis alba, vitiligo or post-inflammatory hypopigmentation. If you have applied it for 1–2 months with no improvement, that is a sign the diagnosis is wrong, not that you need to keep applying it.
Steroid creams and ready-made combination creams Creams that combine a steroid, an antifungal and an antibiotic in one tube are the most common cause of thin, white steroid-damaged skin that the clinic sees, and when applied to pityriasis versicolor they let the yeast spread more widely.
Whitening creams or anti-patch creams with no registration number The high-concentration bleaching agents mixed into illegal creams cause spotty white patches that are hard to correct, and applying whitening cream to the skin around the patches to even out the colour does not help and often damages the surrounding skin further.
Herbs, lime, garlic, balm, or scrubbing the skin to make it peel Repeated irritation causes a rash and then leaves more white marks, and in people with vitiligo, injury and friction can trigger new patches at that spot.
Sunbathing to make the colour blend in The skin around the patches tans but the patches do not, so the marks become more obvious than before. Sun also increases IGH and is a trigger for vitiligo.
Deworming medicine to treat pityriasis alba This is a folk belief with no evidence. Pityriasis alba has nothing to do with worms and nothing to do with milk.
When to see a dermatologist
Immediately White or pale patches that are numb or have reduced sensation, dry skin with no sweating, hair loss, or numbness of the fingers and toes and weakness of the hands and feet together with them.
Within this week Milk-white patches with a sharp edge that enlarge within a few weeks, appear similarly on both sides, have white hair within the patch, or are around the eyes, around the mouth, on the hands or on the genitals.
Within this month No improvement after 2–4 weeks of antifungal cream, skin that begins to thin or turn white after using steroid cream you bought yourself, several white patches on the trunk with no scale that have lasted a long time, or post-rash marks that have not regained any colour in 6 months.
In children White patches present from birth, 3 or more leaf-shaped patches, milk-white sharp-edged patches on the face or hands, or a white ring around a mole.
Whenever you are unsure Examination with the lamp and a scale scraping takes only a few minutes and settles which medicine you need, or whether you need none at all, which costs less than trial and error with several tubes of cream.
For other related skin condition articles, see our hub of skin condition articles by dermatologists
In brief
Small white spots on the skin are not a single disease. The 6 main groups of causes are IGH, pityriasis versicolor, pityriasis alba, vitiligo, post-inflammatory hypopigmentation, and whitening from scars or steroids.
Adults aged 30 and over with white spots of 2–5 mm on the shins and arms and no scale most often have IGH, which is harmless and needs no cream.
Patches with fine scale on the back, chest and neck are pityriasis versicolor, treated with antifungal medicine; the colour returns slowly over 1–3 months and it can recur.
Faint white patches with unclear edges on a child's cheeks are pityriasis alba, not a fungus, which clears on its own with moisturiser and sunscreen.
Milk-white patches with a clear edge that enlarge and are symmetrical are vitiligo; see a doctor early because earlier treatment works better.
Numb white patches are a sign of leprosy and must be examined immediately. It can be completely cured.
Frequently asked questions
What causes small white spots on the skin?
It depends on age, location and the look of the spots. In adults aged 30 and over, spots of 2–5 millimetres with a clear edge, smooth surface and no scale, scattered over the shins or arms, are most often IGH, which is harmless and needs no treatment. If the spots are on the back, chest or neck and have fine scale when lightly scraped, it is usually pityriasis versicolor from yeast. In children, faint white patches with unclear edges on the cheeks are usually pityriasis alba. Spots that are milk-white with a sharp edge and slowly enlarge should make you think of vitiligo. White marks where there was a rash or wound are post-inflammatory hypopigmentation, which regains colour on its own, and spots that are numb to touch must always be checked for leprosy.
How is vitiligo different from pityriasis versicolor?
They differ in colour, scale, location and response to medicine. Vitiligo forms milk-white patches because no pigment is left, with a sharp, crisp edge, a smooth surface with no scale and no itch, and usually appears around the eyes, around the mouth, on the hands, elbows and knees, and symmetrically on both sides. Pityriasis versicolor forms pale, pink or brown patches that are not bright white, with fine powdery scale when lightly scraped, on the back, chest, neck and shoulders. Under a Wood's lamp, vitiligo glows bright bluish-white, and a KOH scraping finds yeast only in pityriasis versicolor. Pityriasis versicolor clears with antifungal medicine, but vitiligo does not respond to antifungal medicine at all and needs anti-inflammatory medicine or medical light therapy.
What causes white patches on my child's skin?
In children the number one cause is pityriasis alba: faint white patches with unclear edges and dry, finely scaly skin on the cheeks, in children aged 3–16 who have dry skin or atopic skin. It is not a fungus, not a worm infection and has nothing to do with milk. It clears on its own over several months to 2–3 years with moisturiser and sunscreen. The second cause is post-inflammatory hypopigmentation where there was atopic eczema or a scratched insect bite, which regains colour in 3–6 months. A single pale patch present since birth is usually a congenital white birthmark. What needs to be examined are bright white sharp-edged patches that enlarge quickly, 3 or more leaf-shaped patches in an infant, and patches that are numb to touch.
What makes the skin turn whitish in patches?
Skin turns whiter than normal when the pigment cells work less for a while, decrease in number, or are destroyed. Patches that are paler than the skin but not bright white usually come from temporary mechanisms, such as pityriasis versicolor, where yeast inhibits pigment production, and pityriasis alba and post-inflammatory hypopigmentation, where inflammation disrupts pigment transfer. Small permanent white spots on an adult's arms and legs are IGH, from pigment cells decreasing with sun and age, while milk-white sharp-edged patches are vitiligo, where the immune system destroys the pigment cells. A first way to tell them apart is to look at size, scale, location, age and spread, and then have a doctor confirm with a Wood's lamp and a scale scraping.
I have white spots on my skin that don't itch. Is that dangerous?
Mostly not dangerous. IGH, pityriasis alba, post-inflammatory hypopigmentation and pityriasis versicolor all cause no itch or only slight itch, and do not affect health. But no itch does not always mean safe, because vitiligo also does not itch yet can spread and should be treated early, and leprosy does not itch either yet permanently damages nerves if left. The signs that need a doctor are spots that are numb or have reduced sensation, spots that are milk-white with a sharp edge and enlarge within a few weeks or appear similarly on both sides, or no improvement after 2–4 weeks of antifungal cream. Without these signs, white spots that do not itch are usually more a cosmetic matter than a disease.
How are white spots on the skin treated?
You need to know the cause first, because no single medicine works for every white spot. IGH needs no treatment, just sunscreen. Pityriasis versicolor uses topical antifungal medicine or medicated shampoo for 2–4 weeks as directed by the doctor, then 1–3 months for the colour to return. Pityriasis alba uses moisturiser, sunscreen and mild soap. Vitiligo uses anti-inflammatory cream, topical immune-modulating cream or medical light therapy at a healthcare facility continuously for several months. Post-inflammatory hypopigmentation and steroid-related whitening wait 3–12 months for the colour to return on its own. Leprosy is completely cured with a combination of several antibiotics for 6–12 months. Do not buy antifungal cream or steroid combination creams to apply before you know the cause.
The information in this article is for general understanding and is not a diagnosis or treatment for any individual. Assessment of skin lesions and the choice of medicine should be made by a doctor.
Written by Dr. Patara Voravutinon, Dermatologist · Last reviewed September 7, 2026
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