Dandruff is not simply a question of cleanliness — it is a skin condition, and for a lot of people it quietly eats away at their confidence. Plenty of us wash more often and wonder why the flakes are still there. Often the reason is that we have never worked out which kind of flaking we actually have, and so we have never cared for it in the right way.
This article covers what dandruff is, how many kinds there are, and which flaky-scalp problems are not dandruff at all — plus how to choose a shampoo and haircare products that suit each one, including the two conditions most often mistaken for dandruff: seborrhoeic dermatitis (seb-derm) and psoriasis.
What is dandruff?
Dandruff is a state in which the skin cells on the scalp shed faster than they should. Normally the skin renews itself roughly every 28 days; when something triggers the cycle it speeds up, and the cells pile into visible white or yellow flakes, usually accompanied by itching.
For the mechanism in full — Malassezia yeast, excess oil and a weakened scalp barrier — read What causes dandruff? How to pick an anti-dandruff shampoo.
Oily dandruff, dry dandruff, seb-derm and psoriasis — what is the difference?
Identifying which scalp problem you have is the heart of caring for it properly. Get the diagnosis wrong and the shampoo will be wrong too — and the problem does not just stay, it can get worse. Oily dandruff, dry dandruff, seb-derm and psoriasis all look alike at first glance, because all four leave sheets of skin cells on the scalp, which is exactly why people so often assume all four are "just dandruff".
Oily dandruff
Oily dandruff comes as large yellow flakes, greasy and sticky, clinging to the scalp and hair
- Appearance: large flakes, yellow, greasy, sticking to the hair — often with a stale smell
- Scalp condition: very oily, with a stale odour
- Where it appears: on the scalp only
Cause: the sebaceous glands produce too much oil (sebum), and that oil is a first-class meal for Malassezia yeast. The yeast breaks the scalp oil down into oleic acid, which seeps in and irritates the skin, driving the cells to shed faster as damp, thick, sticky yellow flakes — and often the stale smell along with them. The more oil the scalp makes, the faster the yeast multiplies.
Dry dandruff
Dry dandruff comes as small white flakes, dry and loose, much like powder
- Appearance: small flakes, often almost dust-like — white, dry and easily shed
- Scalp condition: dry and tight, with a prickling itch that comes from the dryness itself
- Where it appears: on the scalp only
Cause: the scalp has lost its moisture, so the skin flakes away as white powder or small pale sheets. It is most common in cold weather, and in people who wash their hair in very hot water.
Seborrhoeic dermatitis (seb-derm)
Seb-derm often spreads beyond the scalp to oil-rich areas such as behind the ears and beside the nose
- Appearance: thick scales, deep yellow, glossy and greasy
- Scalp condition: red, itchy, inflamed patches
- Where it appears: wherever the sebaceous glands are dense — scalp, forehead, brows, beside the nose, behind and inside the ears, moustache and beard, upper chest, upper back, and so on
Cause: seb-derm is a chronic inflammatory skin condition driven by yeast, inflamed oil glands and a dip in immunity. Things that make it flare:
- Stress — stress raises cortisol, and cortisol drives inflammation
- Too little rest — poor sleep is a major reason immunity drops
- Weather — dry and cold air, or heat that is simply too much, can both set it off
- Food — alcohol and sugar, and for some people heavily spiced food
- A weak skin barrier — when the protective wall is weak the skin loses moisture and reacts to the environment far more easily than skin with a strong barrier
- Skin sensitivity — skin prone to seb-derm is unusually reactive to oleic acid (the by-product of the Malassezia yeast behind oily dandruff), which tips it into inflammation, redness and itching
More detail in What is seborrhoeic dermatitis?
Psoriasis
Psoriasis shows as deep red plaques with sharply defined scale edges, and can appear anywhere on the body
- Appearance: silvery, glossy scale — thick and hard. Lift a scale off and the skin underneath is a red patch that oozes pinpoints of blood
- Scalp condition: intensely red patches with sharply defined scale edges
- Where it appears: anywhere there is skin. Commonly the scalp, forehead, nape, behind the ears, nails, natal cleft, groin, palms, soles, joints, and on the face at the brows and the folds of the nose (where it is often confused with seb-derm)
Cause: psoriasis comes from a fault in the immune system, which makes it far more than a surface problem — it belongs with the autoimmune diseases. Chronic skin inflammation drives the body to produce skin cells too fast, and those excess cells pile up into thick plates of glossy silver scale. Contributing causes include:
- Genetics — psoriasis is not contagious, but it does run in families
- A malfunctioning immune system — white blood cells begin attacking the body's own skin cells. This can follow a viral infection that pushes the immune system into abnormal activity, or long-running chronic inflammation, after which the immune system starts mistaking its own tissue for a target
- Lifestyle — heavy drinking, smoking and obesity all contribute to inflammation in the body
- Certain medicines — some blood-pressure drugs, antipsychotics and antimalarials can trigger psoriasis
- Skin injury — severe sunburn or a major surgical wound can trigger psoriasis at that site, and it can then spread elsewhere
How to choose a shampoo for dandruff, seb-derm and psoriasis
Before anything else, work out whether what you have is dry dandruff or oily dandruff. Once you know that, the right routine follows.
Choosing a shampoo for dry dandruff
Dry dandruff comes from a dry scalp, so the priority is putting water back into the skin.
- Pick a gentle formula that adds moisture to the scalp — look for aloe vera, rosemary, rice bran and vitamin B5
- Avoid sulphates (sulphate-free). Sulphate is a cleansing agent that dries the scalp out, because it strips away too much of its natural oil
- Use a silicone-free treatment, which can go on the scalp itself. Ordinary silicone treatments belong on the lengths only, since silicone risks clogging and irritating the scalp on direct contact
- Do not wash in very hot water — it will only dry the scalp further
Recommended for dry dandruff
- AloEx Organic Black Shampoo
- AloEx Organic Extra Mild Shampoo
- AloEx Everyday Organic Shampoo – Floral Sunshine
Choosing a shampoo for oily dandruff
Oily dandruff is excess scalp oil meeting Malassezia yeast, so the heart of caring for it is controlling the oil and dealing with the yeast at the same time.
- Choose an oil-control shampoo made for oily hair — look for kaffir lime, soap nut, gotu kola, Indian gooseberry and Clinacanthus nutans, which control oil gently, plus salicylic acid to exfoliate the scalp just enough to keep it from over-oiling
- Use a medicated shampoo with an active that targets the yeast directly, such as ketoconazole, piroctone olamine or zinc pyrithione
- Look for soothing, anti-inflammatory ingredients such as aloe vera, henna, Clinacanthus nutans, gotu kola and soap nut
- Avoid harsh sulphate detergents. Beyond leaving the scalp feeling stripped, taking the oil off that fast makes the scalp rush to replace it — and the hair gets greasy faster than before
- Cut back on hair masks, especially oil masks and silicone treatments, which make the scalp oil up sooner
Recommended for oily dandruff
Choosing a shampoo for seb-derm
Seb-derm is more than yeast or dryness alone; a doctor may prescribe something to bring the inflammation down. Washing, though, is basic hygiene you keep doing every day — so a shampoo for seb-derm needs to be gentle, and at the same time calm inflammation, add moisture and deal with the yeast.
- Look for a medicated shampoo that clears Malassezia, the same as for oily dandruff — that yeast is one of several things that make seb-derm worse
- Choose a gentle formula free of common irritants: sulphate-free, silicone-free
- Use a shampoo rich in soothing ingredients such as aloe vera, gotu kola and butterfly pea
- Avoid cooling formulas, which can make the redness flare harder
Seb-derm on the scalp can sometimes improve with the right shampoo and a careful washing routine. But if it is severe, if it appears anywhere beyond the scalp, if it spreads down onto the face, or if it starts to weep, see a doctor for medical treatment.
Recommended for seb-derm
Choosing a shampoo for psoriasis
Psoriasis is a disease that no shampoo can cure, though a shampoo can help take some of the severity out of it. The priority is reducing inflammation and softening the scale — and above all keeping to a gentle, irritant-free shampoo so nothing adds to the inflammation.
- Choose a shampoo with something that thins the scale, such as a salicylic acid or BHA exfoliant — salicylic acid softens thick scale so it lifts away more easily
- Look for moisturising extracts, so the scale softens and releases more readily
- Use a shampoo containing coal tar, the standout ingredient for psoriasis — it slows skin-cell division and reduces redness and itching
- Clobetasol propionate shampoo is prescribed by a doctor for psoriasis patients. It is a steroid shampoo, which brings skin inflammation down quickly — less redness, less swelling, less itching, thinner scale
- Avoid shampoos containing sulphates, fragrance or alcohol, which dry the skin and increase the itch
Recommended for psoriasis
Choosing an AloEx shampoo for dandruff, seb-derm and psoriasis
Every AloEx shampoo is free of the common irritants — sulphate-free, silicone-free, paraben-free — uses natural extracts as its main active ingredients, and is dermatologically tested as suitable for sensitive skin.
AloEx Organic Anti-Dandruff Shampoo — built for oily dandruff
- An organic anti-dandruff shampoo that takes on oily dandruff with high-grade extracts backed by clinical testing for dandruff removal
- Tackles Malassezia with DandErase™, a bio-botanical extract from saffron petals, clinically tested in 70 volunteers and shown to reduce dandruff by up to 95% after only 3 days — plus piroctone olamine for extra anti-dandruff power
- Lifts flakes, helping the scalp exfoliate gently, and controls oil with salicylic acid and Acacia concinna extract
- Keeps the scalp hydrated and strengthens its barrier with a long list of further organic extracts
Full ingredient list and test results on the AloEx Organic Anti-Dandruff Shampoo page
Why AloEx Organic Original Shampoo suits oily dandruff
- A formula designed specifically for people with an oily scalp and oily hair — the condition behind oily dandruff
- Cleans hair and scalp thoroughly without that tight, stripped feeling, so the scalp is not pushed into making more oil
- Natural extracts that help reduce yeast and bacteria — Clinacanthus nutans, jasmine, henna and kaffir lime among them
- Natural extracts that help cut scalp oil, such as kaffir lime and soap nut
Full ingredient list on the AloEx Organic Original Shampoo page
Why AloEx Organic Black Shampoo suits dry dandruff
- Built specifically to add moisture to hair and scalp, so it helps with the dry scalp behind dry dandruff
- Natural moisturising extracts such as black glutinous rice and lemon-lavender oil
- Because AloEx Organic Black Shampoo has a cooling effect, it is not suitable for seb-derm or psoriasis
Full ingredient list on the AloEx Organic Black Shampoo page
Why AloEx Organic Extra Mild Shampoo suits dry dandruff, seb-derm and psoriasis
- Made specifically for very sensitive skin, while adding moisture to hair and scalp
- Natural extracts that add moisture and calm inflammation — rice bran, aloe vera and gotu kola among them
- Because it hydrates and soothes so gently, this formula helps care for dry dandruff, and suits the fragile scalp of someone with seb-derm or psoriasis who has to keep clear of irritants
Full ingredient list on the AloEx Organic Extra Mild Shampoo page
Why AloEx Everyday Organic Shampoo suits dry dandruff
- AloEx Everyday Organic Shampoo – Floral Sunshine gives the scalp the fullest dose of moisture, made for people who like to wash their hair every day
- Natural moisturising extracts such as argan oil, rosemary and rice bran
- It is the AloEx shampoo that adds moisture to the scalp most gently, which makes it a good fit for dry dandruff — the kind that comes from a scalp that has lost its moisture and started to flake
Full ingredient list on the AloEx Everyday Organic Shampoo – Floral Sunshine page
In summary
People confuse dry dandruff, oily dandruff, seb-derm and psoriasis because all four start out looking alike: an itch, and flakes falling onto your clothes. The causes, though, are entirely different. Knowing what is actually behind your flaking scalp is what lets you pick the right shampoo for it, and either solve the problem or take the edge off the symptoms.
Get it wrong and the opposite happens. If you have oily dandruff but reach for a moisturising shampoo meant for dry dandruff, an already oily scalp only gets oilier — the dandruff does not go away, and it may well get worse.
| Oily dandruff | Dry dandruff | Seb-derm | Psoriasis | |
|---|---|---|---|---|
| Cause | A very oily scalp + Malassezia yeast | A dry scalp; washing in warm or very hot water | Chronic inflammation of the oil glands + yeast + an immune system quick to react | An immune fault that makes skin cells divide too fast |
| Flakes / scale | Large yellow flakes, greasy and sticky, clinging to hair or scalp | Small white flakes, dry, shedding like powder | Thick glossy yellow scale, usually with red inflammation beneath | Very thick silvery-white glossy plates, sharply red-edged, bleeding in pinpoints if picked off |
| Where it appears | Scalp | Scalp | Scalp, brows, folds of the nose, behind the ears | Scalp (spreading past the hairline), elbows, knees, nails |
| How to care for it | An oil-control shampoo with an antifungal active | Add moisture, use a gentle formula, avoid hot or very warm water | A medicated antifungal shampoo alternated with an anti-inflammatory, plus enough rest | See a doctor; coal-tar shampoo; steroid medication |
| Which AloEx shampoo | Organic Extra Mild Shampoo | Organic Extra Mild Shampoo |
