Condition

Dandruff

Dandruff is flaking and itching of the scalp caused by low-grade inflammation. It is the mildest form of seborrheic dermatitis. It is not caused by a dirty or a dry scalp, and it settles quickly with the right shampoo used the right way.
Dr. Schwarz, MD · Board-certified dermatologistLast reviewed September 8, 2026
16:9 hero for Dandruff. Never cropped: the tone strip and the corner logo depend on the full frame.

Start here

Dandruff does not mean your scalp is dry - it almost never is. It is the mild end of seborrheic dermatitis, driven by scalp oil, a normal yeast feeding on that oil, and the irritation that follows, so washing less and adding oil makes it worse. Most people who tell me a medicated shampoo failed were rinsing it straight back out; it has to sit on the scalp, not the hair, for a few minutes. Dandruff is controlled, not cured - keep a medicated shampoo once or twice a week even after it clears.

— Dr. Schwarz, Board Certified Dermatologist

Key Facts

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How commonVery common - roughly half of adults have it at some point
Who gets itMost common from the teenage years through middle age, and somewhat more common in men
Curable or managedManaged - it settles with treatment and tends to return when treatment stops
Prescription neededUsually not. Most dandruff clears with over-the-counter medicated shampoo
Time to improveAbout 2 to 4 weeks

What It Is

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Dandruff is flaking and itching of the scalp from mild, ongoing inflammation. It is the mildest form of seborrheic dermatitis, which affects the oily areas of the body - scalp, eyebrows, sides of the nose, behind the ears, and the middle of the chest.

The flakes are clumps of scalp cells shed faster than normal. In plain dandruff they are small, loose and white or gray, and the scalp underneath looks close to normal. As it shifts toward seborrheic dermatitis the scale gets thicker, greasier and more yellow, and the skin underneath turns pink and can feel sore. Itch runs through both, and it is often the worst part.

Dandruff is not contagious, and it is not a measure of how clean you are. It is a reaction between normal scalp oil, a normal scalp yeast called Malassezia, and an immune system that responds to that yeast more strongly in some people than others. That is why two people can wash their hair the same way and only one flakes.

Symptoms

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Small white flakes

Dry Flaking

Fine, loose white flakes that fall onto shoulders, with the scalp feeling tight rather than greasy. It is often worse in cold, dry months. This is the mildest pattern and usually responds to a medicated shampoo used regularly.
Yellow, sticky flakes

Greasy Scaling

Larger yellowish flakes that stick to the scalp and hair rather than falling off. The scalp often looks oily and can smell. This pattern overlaps with seborrheic dermatitis and often needs an anti-yeast shampoo rather than a plain one.
Red, sore scalp

Itchy and Inflamed

A scalp that is red, itchy and sore under the scale, sometimes with scratch marks or small scabs. Scratching thickens the scale and keeps the cycle going. Persistent soreness is worth having looked at, because other scalp conditions look similar.

How It Looks by Skin Tone

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A part line in straight light hair, seen from above, on pale skin. White-gray flakes sit along the part and the scalp beneath them looks pink.A part line in dark wavy hair, seen from above, on medium olive skin. Greasy yellow-white scale sits along the part and the scalp beside it looks dull pink-brown.A part line in tightly coiled hair, seen from above, on mid-brown skin. Gray-white scale sits along the part, and the scalp beside it shows patches lighter than the surrounding skin rather than red.A part line in tightly coiled hair, seen from above, on deep brown skin. Gray-white scale sits along the part, and several smooth, evenly lighter patches with soft edges sit on the scalp beside it.
LightMediumBrownDeep

On deeper skin tones, dandruff and seborrheic dermatitis often show up as lighter patches rather than red ones. Inflammation here tends to leave hypopigmentation - areas that have lost some pigment - and those pale patches can be more noticeable and more upsetting than the flaking. They usually recover once the inflammation is controlled, but it takes months. On the face it often takes a ring or petal shape around the nose and cheeks, easy to mistake for something else.

Because the redness is muted, dandruff on deeper skin tones is regularly judged milder than it is and treated too lightly. Scale, itch and pale or dark patches are more reliable here than redness. Hair care changes the advice. Many people with tightly coiled or chemically treated hair wash weekly or less to protect the hair, and heavy oils, pomades and grease often go along the parts. Both feed the problem. The fix is not washing more often, which damages hair, but making the washes count - part the hair, apply the medicated shampoo straight to the scalp, ideally with an applicator bottle, leave it on five to ten minutes, then rinse and condition the lengths only. Under braids, locs or weaves, a diluted medicated shampoo or a scalp solution reaches the skin better than a lather.

Where It Shows Up

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Front view of a head with red marks spread across the whole scalp and along the hairline. The face is clear.
The scalp, all over
Dandruff is spread across the whole scalp rather than sitting in patches, and it is often heaviest at the crown and along the part. Flakes on the shoulders come from the scalp above them. If flaking runs past the hairline onto the face and ears, that is usually seborrheic dermatitis rather than plain dandruff.

What Happens in the Skin

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This is what is going wrong under the skin, in the order it happens. Click a step to see it.

How Dandruff happens
Skin basics
BARRIEREPIDERMISDERMISPOREOILGLAND0NORMAL SCALP1OIL ON THE SCALP2YEAST FEEDING ON THE OIL3THE SKIN REACTS TO IT4FAST SHEDDING AND FLAKING

Every hair follicle on the scalp has an oil gland attached to it, feeding a thin film of sebum onto the surface. The dead cells at the top of the skin come away one at a time, far too small to see. That oil is normal and the scalp needs it, and there is more of it after puberty.

Glands in the scalp produce sebum, which is normal and necessary. There is simply more of it after puberty, and more of it on some people than others, and that is the fuel for everything that follows.

A yeast called Malassezia lives on almost everyone's skin. It feeds on that oil and breaks it down, leaving free fatty acids behind on the scalp. Nothing here is abnormal yet — this is the same on people who never flake.

In some people the skin responds to those breakdown products with low-grade inflammation. This is the step that decides who gets dandruff and who does not — it is how strongly you react, not how much yeast you carry.

Irritated skin cells are pushed to the surface faster than they should be, so instead of falling away invisibly they come off in clumps big enough to see. The barrier is disrupted at the same time, which is why it itches and why scrubbing makes it worse. Everything on the lists below is pushing on this step.

The outer film of dead cells and oil. It holds water in and keeps irritants out, and it is thinner than a sheet of paper. Almost every dry, itchy, stinging skin problem starts here.

The outer layer, and the only one anything in a jar reaches. It renews itself constantly: a cell made at the bottom takes about a month to reach the surface and flake off. Most of what a skincare product does, it does here.

The living layer underneath, holding the blood vessels, the nerves and the collagen. It is where lasting change happens and it is hard to reach: most of what is sold for the skin never gets this far.

Three things have to line up. The oil glands on your scalp produce sebum, which is normal. A yeast called Malassezia, which lives on almost everyone, feeds on that oil and breaks it into free fatty acids. In some people the skin reacts to those breakdown products with low-grade inflammation.

That inflammation causes the visible problem. Irritated cells shed faster than they should, so instead of falling away invisibly they come off in clumps big enough to see. The scalp barrier is disrupted too, which is why it itches and why harsh treatment backfires.

Two points follow. It is not the amount of yeast that matters - almost everyone carries it - but how strongly your skin reacts. And treatment works by reducing the yeast and calming the inflammation, not by cleaning harder.

Risk Factors

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Some people are simply more prone to dandruff, and none of this means the scalp is dirty.

Hormones & oil
Age and hormones
Dandruff usually starts after puberty, when oil glands become more active, and is commonest from the teens to middle age.
Hormones & oil
Male sex
Men get it somewhat more often than women, probably oil production.
Hormones & oil
Naturally oily skin and scalp
More oil gives the yeast more to feed on.
Everyday triggers
Cold, dry seasons
Flares cluster in autumn and winter, with less sunlight and more indoor heating.
Everyday triggers
Stress, illness and poor sleep
They do not cause dandruff, but flares follow a run-down stretch.
Other health conditions
Neurologic conditions
Seborrheic dermatitis is much more common, and more stubborn, with Parkinson's disease and some others.
Other health conditions
A weakened immune system
Severe or hard-to-treat seborrheic dermatitis is more common in people who are immunosuppressed, including untreated HIV.
Other health conditions
Some medicines
Lithium and some medicines acting on dopamine are linked with seborrheic dermatitis. Never stop one on your own - ask your doctor.

Course

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Dandruff comes in waves - quiet stretches broken by flares. It can carry on for decades without getting steadily worse, and it follows a rough arc through life.

BabiesFirst weeks or months of life
Cradle cap is a separate thing

It looks alarming, does not itch, and clears on its own. It is not adult dandruff and rarely needs medicated treatment.

Scalp
After pubertyTeenage years
This is when dandruff usually starts

Dandruff begins after puberty, and the teenage years open its most active stretch.

Teens to middle ageThe most active years
Flares cluster in autumn and winter

Cold air, indoor heating and less sunlight all seem to matter, and summer is usually easiest. Flares also follow illness, poor sleep and stress.

Once treatedTwo to four weeks, then ongoing
It settles quickly and returns when you stop

Flaking and itch usually settle within two to four weeks, and come back within a few weeks of stopping. That is not failure - it is why dandruff is maintenance, with a medicated shampoo once or twice a week even when the scalp looks normal.

What Makes It Better & Worse

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Dandruff is four problems — oil on the scalp, yeast growing in it, an immune reaction, and flaking. The treatment depends on which step is driving it, so an oily, itchy scalp needs something different from thick scale.

What is driving yours?

FATPOREOILGLANDBARRIEREPIDERMISDERMIS

Glands in the scalp produce sebum, which is normal and necessary. There is simply more of it after puberty, and more of it on some people than others, and that is the fuel for everything that follows.

A yeast called Malassezia lives on almost everyone's skin. It feeds on that oil and breaks it down, leaving free fatty acids behind on the scalp. Nothing here is abnormal yet — this is the same on people who never flake.

In some people the skin responds to those breakdown products with low-grade inflammation. This is the step that decides who gets dandruff and who does not — it is how strongly you react, not how much yeast you carry.

Irritated skin cells are pushed to the surface faster than they should be, so instead of falling away invisibly they come off in clumps big enough to see. The barrier is disrupted at the same time, which is why it itches and why scrubbing makes it worse. Everything on the lists below is pushing on this step.

What helps

  • Wash more often during a flare Removing oil removes the yeast's food.

What makes it worse

  • Washing less often when it flares More oil means more yeast.
  • Heavy oils, pomades and greases They feed the yeast.
  • Sweat, hats and helmets Trapped heat and moisture.
  • Product build-up Dry shampoo and styling products mix with oil.

What helps

  • Zinc pyrithione shampoo Cuts yeast, calms the scalp, fine long term.
  • Ketoconazole 1 percent shampoo Over the counter, and highly effective.
  • Selenium sulfide shampoo Cuts yeast and slows shedding, but can discolor light hair.
  • Leave it on for five minutes Turns a useless shampoo into one that works.
  • Apply it to the scalp, not the hair Part the hair and work it in.
  • Rotate two different actives Alternating beats one alone over months.
  • Keep using it after it clears Once or twice a week keeps dandruff away.
  • Some sunlight Seborrheic dermatitis usually improves in summer.
  • Give it two to four weeks Judge a shampoo at a month, not a week.

What makes it worse

  • Rinsing medicated shampoo straight out The active needs contact time.
  • Stopping the shampoo as soon as it works Maintenance, not a course.

What helps

  • A scalp solution for a bad flare A short course of steroid or ciclopirox.

What makes it worse

  • Scratching and picking off scale Damages the barrier, restarts the itch.
  • Stress, illness and poor sleep Not a cause, but flares track them.

What helps

  • Coal tar shampoo Slows shedding, which helps heavy flaking.
  • Salicylic acid shampoo Lifts thick, stuck-down scale rather than treating yeast.
  • Soften thick scale before treating it An oil or salicylic acid for an hour lifts it.

What makes it worse

  • Cold, dry weather and indoor heating Dry air makes flaking obvious.
  • Harsh scrubbing and very hot water Leaves the scalp sore, the yeast untouched.

How These Treatments Work

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Treatments for Dandruff do not all work in the same place. Tap one to see where it acts.

Pick a treatment
Skin basics
BARRIEREPIDERMISDERMISPOREOILGLANDKILLS YEASTLIFTS THE FLAKESTAKES AWAY ITS FOODCALMS THE REACTION

The same yeast and the same reaction as seborrheic dermatitis, on the scalp.

Loosens what has already built up so the shampoo reaches the scalp.

Scalp oil is what the yeast lives on.

For a scalp that is red and itchy, not just flaky.

The outer film of dead cells and oil. It holds water in and keeps irritants out, and it is thinner than a sheet of paper. Almost every dry, itchy, stinging skin problem starts here.

The outer layer, and the only one anything in a jar reaches. It renews itself constantly: a cell made at the bottom takes about a month to reach the surface and flake off. Most of what a skincare product does, it does here.

The living layer underneath, holding the blood vessels, the nerves and the collagen. It is where lasting change happens and it is hard to reach: most of what is sold for the skin never gets this far.

Over-the-Counter Products

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Everything here you can buy without seeing anyone.

Four dandruff shampoo bottles: DHS Zinc, Head and Shoulders Classic Clean, CeraVe Anti-Dandruff and Head and Shoulders Bare16:9 hero for Pyrithione Zinc. Never cropped: the tone strip and the corner logo depend on the full frame.
Strong evidence
The workhorse dandruff shampoo: it reduces the yeast and calms the scalp, and it is gentle enough to keep using for years. Part the hair, work it into the skin rather than the lengths, and leave it on for five minutes. It is a good choice for color-treated, gray or relaxed hair because it does not discolor.
16:9 hero for Ketoconazole. Never cropped: the tone strip and the corner logo depend on the full frame.Diagram: how Ketoconazole works in the skin
Strong evidence
The 1 percent shampoo on the shelf is a proper antifungal and one of the most effective things you can buy for dandruff. Twice a week during a flare, then once a week to hold it. Pairing it with zinc pyrithione and alternating the two tends to keep working better over months than either one used alone.
Two Selsun Blue bottles, two Head and Shoulders Clinical Strength bottles and a Vichy Dercos bottle and box16:9 hero for Selenium Sulfide. Never cropped: the tone strip and the corner logo depend on the full frame.
Strong evidence
Reduces the yeast and also slows how fast scalp cells shed, which makes it useful when the flaking is heavy. Rinse it thoroughly. The catch is color: it can discolor light, gray, relaxed or color-treated hair, so zinc pyrithione or ketoconazole is usually the better pick for those.
Five medicated scalp products on white, including Amazon Basics tar gel, T+Plus, MG217, RoyceDerm and Nizoral16:9 hero for Coal Tar. Never cropped: the tone strip and the corner logo depend on the full frame.
Moderate evidence
Works by slowing the shedding rather than by treating the yeast, so it suits thick, heavy flaking more than a mildly itchy scalp. It smells strongly and it stains light hair and fabric, which is why most people use it only during a flare. It is also useful when scalp psoriasis is in the picture too.
Paula's Choice 2% BHA exfoliant, La Roche-Posay Effaclar cleanser and a CeraVe psoriasis cream pumpLabeled cutaway diagram of a single skin pore, headed Salicylic Acid. The epidermis is a brick-textured band across the top and the dermis is pink below it, with a yellow oil gland at the base of the pore and a small cluster of bacteria inside it. A single dark navy callout line points into the top of the pore: decreases dead cells in pore. There are no other callouts, so the drawing shows one effect where the other ingredient diagrams show two or three.
Moderate evidence
This one lifts scale rather than treating the cause. It is the right choice when the scale is thick and stuck down and other shampoos cannot reach the skin underneath. Use it first to clear the way, then follow with an anti-yeast shampoo — on its own it will not stop the dandruff coming back.
Five dark glass tea tree essential oil bottles with glass droppers and one green box on white16:9 hero for Tea Tree Oil. Never cropped: the tone strip and the corner logo depend on the full frame.
Limited evidence
A 5 percent tea tree shampoo did beat a plain shampoo in one small trial, so it is not nothing. It is weaker than the standard actives and there is much less behind it. It is also a common cause of allergic contact dermatitis, so if the scalp becomes more itchy and irritated on it, that is a reason to stop rather than to persist.
Oils and home rinses
Oils and home rinses
Weak evidence
Coconut oil, castor oil and vinegar rinses come up constantly and none of them treat dandruff. An oil left on the scalp gives the yeast more of exactly what it grows on. There is one genuine use: an oil applied for an hour before washing softens thick, stuck-down scale so it lifts without scraping — then it gets washed out.

Prescriptions

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These need a prescription.

16:9 hero for Ketoconazole. Never cropped: the tone strip and the corner logo depend on the full frame.
Ketoconazole 2% shampoo
Strong evidence
Double the strength of the version on the shelf, and the usual first prescription when a month of over-the-counter shampoo has not shifted it. Twice a week for a month, five minutes on the scalp each time. Once it is clear, most people drop back to an over-the-counter shampoo for maintenance rather than staying on this.
16:9 hero for Clobetasol Propionate. Never cropped: the tone strip and the corner logo depend on the full frame.
Clobetasol Propionate
Strong evidence
A potent steroid, prescribed for the scalp as a solution, foam or shampoo, that settles a red, sore, intensely itchy flare within days. It is for short bursts of two to four weeks, not for keeping on hand. It does nothing about the yeast, so the medicated shampoo carries on alongside it and takes over afterwards.
16:9 hero for Roflumilast Cream (Zoryve). Never cropped: the tone strip and the corner logo depend on the full frame.Diagram: how Roflumilast Cream (Zoryve) works in the skin
Strong evidence
A newer non-steroid foam approved for seborrheic dermatitis, used once a day on the scalp and face. It calms the inflammation without the thinning that comes with long-term steroid use, which makes it a reasonable option for people who keep needing steroid courses. Cost and insurance are usually the limiting factor.
A white shampoo bottle on a white background, with a plain white label reading Ciclopirox and a blue swoosh beneath it.
Ciclopirox shampoo
Moderate evidence
A different antifungal, and the usual next step when ketoconazole has stopped working or was never tolerated. It is used two or three times a week in the same way, with contact time on the scalp. Rotating it with a zinc pyrithione shampoo is a common way to keep a stubborn scalp under control.
16:9 hero for Tacrolimus (Protopic). Never cropped: the tone strip and the corner logo depend on the full frame.Diagram: how Tacrolimus (Protopic) works in the skin
Moderate evidence
A non-steroid ointment used mainly where dandruff has spread onto the face — the eyebrows, the creases beside the nose, behind the ears. It calms the same inflammation without thinning that thin skin, which matters when the area needs treating on and off for years. It stings for the first few days. It is awkward to apply in hair, so it is rarely the choice for the scalp itself.
16:9 hero for Fluconazole. Never cropped: the tone strip and the corner logo depend on the full frame.Diagram: how Fluconazole works in the skin
Limited evidence
An antifungal tablet, occasionally used for a short course when seborrheic dermatitis is severe, widespread, or not responding to anything applied to the skin. Ordinary dandruff never needs it. It also does not keep it away — shampoo maintenance still has to carry on afterwards — and it interacts with a number of common medicines.

Procedures

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These are done in the office, usually over several visits.

No procedures listed yet.

When to See a Dermatologist

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Most dandruff never needs a dermatologist - two to four weeks of medicated shampoo used properly clears most of it; contact time is what people skip. Book if a month of over-the-counter medicated shampoo with proper contact time has changed nothing, if the scalp is red, sore, weeping or crusted rather than just flaky, if thick, sharply edged plaques with silvery scale spread past the hairline, if you are losing hair from the affected areas, or if the flaking has reached the face, eyebrows, ears or chest. Sudden severe seborrheic dermatitis in an adult who never had it is worth a look, and a child with a scaly patch, broken-off hairs or a bald area should be seen, not treated at home - that can be a fungal infection needing oral treatment. No test confirms dandruff. I diagnose it by the scale, whether the skin underneath is inflamed, and where else it sits - eyebrows, nose, ears, chest.

— Dr. Schwarz, Board Certified Dermatologist

Complications

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Lookalikes

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Scalp Psoriasis

Both flake, both itch, and both sit on the scalp, so scalp psoriasis is mistaken for stubborn dandruff for years at a time. Psoriasis makes thicker plaques with a sharp, clearly drawn border and silvery-white scale, and they often carry on past the hairline onto the forehead, behind the ears or down the back of the neck. Dandruff has soft, ill-defined edges and stays on the scalp. It matters, because psoriasis rarely clears with an anti-yeast shampoo alone.

Head Lice

The eggs look like flakes, and this mix-up goes both ways. The test is whether it moves: a flake slides off the hair easily, and a louse egg is glued to the shaft and has to be pulled along it. Lice also itch far more, mostly behind the ears and at the back of the neck, and they leave scratch marks there. Lice need treating, and a medicated shampoo does nothing to them.

Ringworm

On the scalp this fungal infection is called tinea capitis, and it is seen mainly in children, where a scaly flaking patch is easy to read as dandruff. The difference is that it makes one round patch rather than general flaking, and the hairs inside it are broken off short or missing altogether. It is contagious and it needs antifungal tablets, because shampoo cannot reach fungus inside the hair, so a scaly bald patch on a child is worth a same-week appointment.

Myths

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  • "Dandruff means my scalp is dry." Usually the opposite. Dandruff is commonest on oily scalps, and the yeast behind it feeds on that oil. Treating it like dryness - washing less, adding oils - reliably makes it worse.
  • "Dandruff means I do not wash my hair enough." Hygiene does not cause dandruff, and plenty of people who wash daily get it. Washing helps because it removes the oil the yeast feeds on, but you flake because of how your skin reacts.
  • "Dandruff is contagious." It is not The yeast involved already lives on nearly everyone. You cannot catch dandruff from a hairbrush, a pillow or another person.
  • "Coconut oil or castor oil will fix it." Oils loosen thick scale before a wash, which is useful. Left on the scalp they are food for the yeast. Use an oil as a pre-wash treatment and wash it out.
  • "Dandruff causes baldness." It does not cause permanent hair loss. A badly inflamed scalp scratched hard sheds more hair temporarily, and that recovers once the inflammation settles. Ongoing hair loss needs its own assessment.
  • "Once it clears, you can stop the shampoo." The commonest reason dandruff comes back. It is controlled, not cured, and most people need a medicated shampoo once or twice a week indefinitely.

Questions Patients Ask

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Is dandruff caused by a dry scalp?

Usually not. It is commonest on oily scalps, and the yeast behind it feeds on that oil. The scalp can feel dry and tight because it is inflamed and the barrier is disrupted, which is not the same as being short of moisture. Treating it as dryness makes it worse.

How often should I wash my hair if I have dandruff?

More often than you otherwise would, at least during a flare, because washing removes the oil the yeast lives on. If frequent washing damages your hair, change how you wash rather than how often - medicated shampoo straight onto the scalp, five minutes, condition only the lengths.

Does dandruff cause hair loss?

Not permanently. A very itchy, inflamed scalp that gets scratched or picked sheds more hair for a while, and that recovers once the inflammation settles. Thinning or bald patches need their own assessment, not a stronger shampoo.

Why did my shampoo stop working?

Usually one of two things. Either contact time slipped and it is being rinsed straight out again, or the scalp has stopped responding to that active. Rotating two medicated shampoos, such as zinc pyrithione and ketoconazole, tends to keep working.

Is dandruff related to the flaky redness around my nose and eyebrows?

Yes - the same condition in a different place. Seborrheic dermatitis affects the oily areas of the body, and the scalp is the most obvious one. The face usually responds to a gentle antifungal cream or a short course of a mild anti-inflammatory prescribed for that area, not to shampoo left on the skin.

Can I use medicated shampoo on colored or chemically treated hair?

Generally yes, but the active matters. Selenium sulfide and coal tar can discolor light, gray, relaxed or color-treated hair. Zinc pyrithione and ketoconazole are the usual choices, and conditioning the lengths limits drying of the hair shaft.

References

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