Conditions · Hair · Scalp Health

Dandruff & Seborrhoeic Dermatitis

Medically reviewed by Dr Sin Yong · Last reviewed · 9 min read · Assessed personally by Dr Sin Yong · Jump to questions

Dandruff and seborrhoeic dermatitis are one condition at two volumes: an inflammatory response to Malassezia yeast on an oily scalp — flaking at the mild end, red greasy-scaled patches at the louder end. It is chronic, it flares with stress and climate, and it matters to your hair: a persistently inflamed scalp is a worse place to grow it, and the itching-scratching-shedding loop does real mechanical damage.

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Dandruff and seborrhoeic dermatitis are one condition at different intensities: an individual inflammatory response to Malassezia yeast on an oily scalp, ranging from fine flaking to red patches with greasy yellow scale. It is chronic and relapsing, managed rather than cured, and usually starts with an antifungal shampoo routine once psoriasis and dryness are excluded.

In brief
  • Dandruff and seborrhoeic dermatitis are one condition at different intensities, from fine flaking to red, greasy, scaly patches.
  • It is an individual inflammatory response to Malassezia yeast on an oily scalp, not a sign of poor hygiene.
  • It is chronic and relapsing, managed rather than cured, usually with an antifungal shampoo routine.
Key takeaways
  • Dandruff and seborrhoeic dermatitis are one condition at different intensities, from fine flaking to red, greasy, scaly patches.
  • It is an individual inflammatory response to Malassezia yeast on an oily scalp, not a sign of poor hygiene.
  • It is chronic and relapsing, managed rather than cured, usually with an antifungal shampoo routine.
  • Chronic scalp inflammation and scratching are associated with increased shedding, so calming the scalp supports hair.
  • Psoriasis, a dry scalp, scarring or patchy hair loss can look similar and need a physician's diagnosis.
On this page
  1. Key Facts
  2. What does dandruff look like?
  3. Why does your scalp flake?
  4. Dandruff, dryness, or psoriasis?
  5. What actually works — and what it means for your hair
  6. What doesn't work for dandruff?
  7. Dr Sin Yong’s Viewpoint
  8. Which type do you have?
  9. What does not work, and why
  10. When to see a doctor
  11. Myths we hear in clinic
  12. Questions Patients Actually Ask

Key Facts

The organism
Malassezia — the same oil-feeding yeast behind fungal acne — metabolising scalp sebum into irritants
The response
Not everyone reacts: seborrhoeic dermatitis is an individual inflammatory response, not an infection
The spectrum
Simple dandruff → itchy red patches with greasy yellow scale (scalp, brows, nose creases, beard)
The hair connection
Chronic scalp inflammation associates with increased shedding; scratching adds mechanical breakage
The rhythm
Chronic and relapsing — flares with stress, fatigue, heat and humidity; managed, not cured
Evidence base
Antifungal-first therapy — ketoconazole-class shampoos — with anti-inflammatory support during flares
Who assesses this
A physician — flake type separates seb derm from psoriasis and dryness
Typical first step
Antifungal-first shampoo routine, used correctly and maintained

What does dandruff look like?

Seborrhoeic dermatitis: erythema and greasy scale in the sebaceous zones
Seborrhoeic dermatitis: erythema and greasy scale in the sebaceous zones. Image: Roymishali, via Wikimedia Commons (CC BY-SA 3.0).
Scaly plaques over the scalp
Scaly plaques over the scalp. Image: Amras666, via Wikimedia Commons (CC BY-SA 3.0).
Seborrhoeic scaling in the beard and moustache area
Seborrhoeic scaling in the beard and moustache area. Image: Kein Trinkwasser, via Wikimedia Commons (CC BY-SA 3.0).

Why does your scalp flake?

The reviews describe a three-part mechanism: abundant sebum, Malassezia yeast feeding on it and releasing irritant fatty-acid by-products, and — the deciding factor — an individual inflammatory response to those by-products [1,2]. Everyone hosts the yeast; only responders flake. That framing explains the condition's behaviour: it lives where oil glands crowd (scalp, brows, nose creases, beard, chest), it flares with stress, fatigue and Singapore's heat, and it relapses after every 'cure' because the yeast and the sebum are permanent residents. Malassezia enthusiasts may recognise the organism — it is the same yeast behind fungal acne, running a different scam at a different address.

Dandruff, dryness, or psoriasis?

Three flaky scalps, three plans. Seborrhoeic flaking is greasy — yellowish scale on an oily, often itchy scalp, worse in the oily zones. A genuinely dry scalp sheds fine white powder without redness and drinks moisture gratefully — and is rarer than the shampoo aisle implies. Psoriasis builds thick, silvery, sharply bordered plaques that often extend past the hairline and deserve their own medical pathway. And flaking with broken hairs or patchy loss needs the full differential — the shedding and areata guides cover the neighbours. Scale plus scarring or pustules is specialist territory, promptly.

What actually works — and what it means for your hair

Evidence-based care is antifungal-first: ketoconazole-class and related medicated shampoos, used correctly — lathered, left to work, and continued at maintenance frequency after clearing, because discontinuation is the classic relapse trigger [1,2]. Flares earn short courses of anti-inflammatory scalp treatment under supervision; routine harshness earns nothing. The hair dividend is real: chronic scalp inflammation associates with increased shedding, and calming the scalp removes both that pressure and the scratching that snaps hairs mechanically. In patients on the hair loss programmes, scalp control is sequenced first — treatments for pattern loss work better delivered onto a quiet scalp, and the H2LT and Regenera pathways assume one.

What doesn't work for dandruff?

Scratching the scale off — mechanical damage plus flare fuel. Oiling an oily condition — feeding Malassezia its favourite meal; coconut-oil scalp masks are this condition's accelerant, not its remedy. Antibacterial soaps — wrong kingdom again. Shampoo-hopping weekly — antifungal actives need consistent use to hold the yeast down. And quitting the medicated shampoo the week the flakes vanish — maintenance is the treatment; stopping is the relapse plan.

“Everyone hosts the yeast; only some scalps argue with it — seborrhoeic dermatitis is the argument, and maintenance is the truce.”

— Dr Sin Yong

Dr Sin Yong’s Viewpoint

Dandruff is the condition everyone treats and nobody diagnoses. It is an inflammatory truce with a yeast that never leaves — which is why the shampoo that 'stopped working' was usually just stopped. Maintenance is the treatment. And I care about it beyond the flakes: hair-loss treatment works better delivered onto a quiet scalp.

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Which type do you have?

Flaky scalp: dandruff and its look-alikes
Type / look-alikeHow to recognise itWhat it needsWhat does not work
Dandruff or seborrhoeic dermatitisGreasy yellowish flakes, itch and redness in oily zonesAntifungal-first medicated shampoo, continued at maintenance frequencyScratching, oiling the scalp and stopping once flakes clear
Dry scalp without inflammationFine white powder without redness, with tight-feeling skinGentle cleansing and moistureHarsh cleansing that strips the skin further
Scalp psoriasis as a look-alikeThick, silvery, sharply bordered plaques, often past the hairlineIts own medical pathway after diagnosisTreating it as dandruff with shampoo alone
Scarring or pustular scalp conditionsScale with scarring, pustules or painful areasPrompt medical review, with dermatology referral where neededHome shampoo experiments without a diagnosis
Flaking with patchy hair lossScale alongside broken hairs or bald patchesFull assessment of the cause of the hair lossAssuming dandruff explains the hair loss

What does not work, and why

When to see a doctor

Myths we hear in clinic

“Dandruff is caused by poor hygiene.”

It is an inflammatory response to a yeast on an oily scalp, and harsh over-washing can aggravate it.

“Once the flakes clear, the medicated shampoo can stop.”

Maintenance-frequency use is part of the treatment, and stopping early is the usual trigger for relapse.

Questions Patients Actually Ask

Is dandruff caused by poor hygiene?+

No — it is an inflammatory response to a yeast on an oily scalp. Overwashing with harsh products can worsen it; the fix is the right active, not more scrubbing.

Can dandruff cause hair loss?+

Chronic scalp inflammation associates with increased shedding, and scratching breaks hair mechanically. Controlling the dermatitis removes both pressures — though zonal pattern thinning has its own cause and its own plan.

Why does it come back every time I stop the shampoo?+

Because the yeast and the sebum never left — seborrhoeic dermatitis is managed, not cured, and maintenance-frequency use of the antifungal is the evidence-based truce.

My flakes are on my brows and nose creases too — same thing?+

Yes — those are classic seborrhoeic sites, treated with the same antifungal-first logic in face-appropriate formats.

Is it related to stress?+

Flares track stress, fatigue and illness reliably — stress modulates the inflammatory response. Managing it helps; it does not replace antifungal treatment.

When is a flaky scalp not dandruff?+

Thick silvery plaques crossing the hairline (psoriasis), scale with scarring or pustules, or flaking with patchy hair loss — each earns proper medical diagnosis rather than a shampoo experiment.

What causes dandruff?+
Dandruff arises from abundant scalp sebum, Malassezia yeast feeding on it and releasing irritant by-products, and an individual inflammatory response to those by-products. Everyone hosts the yeast, but some scalps react. Stress, fatigue, heat and humidity are associated with flares. Poor hygiene is not the cause, and harsh over-washing can make flaking worse.
Can dandruff be fully cured?+
Dandruff and seborrhoeic dermatitis are chronic and relapsing, so they are managed rather than cured. Flaking usually settles with a correctly used antifungal-first routine, but the yeast and the sebum remain, and flakes commonly return if the routine is stopped. Maintenance-frequency use is part of treatment. Response varies, and no promise of lasting clearance can be made.
Which treatment suits dandruff?+
It depends on the type of flaking and what the scalp shows. Greasy scale usually responds to an antifungal-first medicated shampoo, used correctly and continued at maintenance frequency, with short supervised anti-inflammatory courses for flares. Dryness, psoriasis, scarring and patchy hair loss each need a different plan, which is why a physician examines first.
How much does dandruff treatment cost in Singapore?+
The cost of dandruff treatment in Singapore depends on the assessment findings, whether medicated products or prescription treatment are needed, whether hair loss is also being assessed, and the number of review visits. A written quote is given at consultation, after the scalp has been examined. The consultation also decides what is advised, so no figure is given in advance.

References

  1. Seborrheic Dermatitis: Exploring the Complex Interplay with Malassezia — International Journal of Molecular Sciences (PMC).
  2. Seborrhoeic Dermatitis of the Scalp — PubMed.

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Medically reviewed by Dr Sin Yong, MBBS (NUS), MRCS (Edinburgh) · Last updated 7 September 2026 · Editorial policy

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