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Dandruff vs Dry Scalp: Differences & Treatments


Not sure why your scalp is irritated? You’re not alone. 42% of people have an unhealthy scalp* but many aren’t sure what the cause is. We reveal what causes dandruff vs what causes a dry scalp, so you can work out how best to treat your unhappy roots.

With dandruff you will experience large flakes and an oily scalp/roots.

What Causes Dandruff

With a dry scalp you will experience small flakes and a dry, tight scalp.

What Causes Dry Scalp

With dandruff you will experience large flakes and an oily scalp/roots.

Read « Dandruff » part

With a dry scalp you will experience small flakes and a dry, tight scalp.

Read « Dry Scalp » part
Anti-Dandruff hair routine

What Causes Dandruff?

We all shed our skin. In fact, humans shed their entire outer layer of skin every 2-4 weeks. But dandruff occurs when the skin on our scalp builds up. Most of the time dandruff clusters along the top of the head, behind the ears and at the nape of the neck. There are various known triggers, so if you are dealing with unwanted dandruff then it could be down to any of the following causes:

1) MALASSEZIA BACTERIA

Most cases of dandruff can be traced to a single-celled bacteria that exists on all scalps called malassezia. It feed on the oils and produces oleic and can lead to irritation, redness and dandruff flakes.

2) USING THE WRONG HAIR AND SCALP PRODUCTS

This can lead to a condition known as dermatitis (a general term for skin irritation) and dandruff. It’s important to wash hair with dandruff regularly to dislodge the flakes, but you need to ensure you’re using the right products.

What causes Dandruff?

What Causes Dandruff?

We all shed our skin. In fact, humans shed their entire outer layer of skin every 2-4 weeks. But dandruff occurs when the skin on our scalp builds up. Most of the time dandruff clusters along the top of the head, behind the ears and at the nape of the neck. There are various known triggers, so if you are dealing with unwanted dandruff then it could be down to any of the following causes:

1) MALASSEZIA BACTERIA

Most cases of dandruff can be traced to a single-celled bacteria that exists on all scalps called malassezia. It feed on the oils and produces oleic and can lead to irritation, redness and dandruff flakes.

2) USING THE WRONG HAIR AND SCALP PRODUCTS

This can lead to a condition known as dermatitis (a general term for skin irritation) and dandruff. It’s important to wash hair with dandruff regularly to dislodge the flakes, but you need to ensure you’re using the right products.

Kerastase Hair Treatment for Dandruff

3) A SUDDEN DROP IN TEMPERATURE

When the colder temperatures hit, there tends to be less moisture in the air both outside and inside where central heating can dehydrate the skin. This dryness can trigger a dandruff flare-up.

4) OTHER FACTORS THAT CAUSE DANDRUFF

While stress can’t cause dandruff to start, it can cause dandruff to worsen. The same goes for external aggressors like pollution.


A concern some have, is can dandruff cause hair loss? And, in short, the answer is no. However, if your scalp is irritated enough for you to itch it a lot, you could damage the scalp which could, in turn, slow hair growth.
If your main concern is hair loss, we recommend you our Genesis Collection.

How To Treat Dandruff

If, by now, you have realised you have dandruff you might be wondering - how do I treat it?
To treat dandruff, you need to look at using products specially formulated with dandruff and sensitive scalp in mind.

Bain Anti-Pelliculaire is an anti-dandruff shampoo, which acts on two types of dandruffs, dry and oily flakes. The anti-relapse action treats the scalp to remove visible flakes from recurring for up to 8 weeks.

Bain Divalent is a balancing shampoo for oily roots. It purifies the scalp without irritation, you can expect fewer flakes and more volume at the roots while the ends of your hair will be left soft and shiny.

Potentialiste Serum contains 10% Bifidus Prebiotic to help soothe and balance the scalp - making it the perfect addition to any anti-dandruff routine.

Once a week opt for a multi-masking routine. On your roots use Argile Equilbrante, the detox clay works to help purify the scalp, leaving it feeling invigorated and refreshed. Then apply Masque Réhydratant on your mid-length and ends. The lightweight gel-masque quenches the hair - drawing moisture into your strands, whilst also leaving the hair glossy and ready to style.

Finally, Scrub Energisant is another tool you can have in your anti-dandruff kit. Designed for an oily-prone scalp this scrub helps tackle dandruff. Packed with detoxifying sea salt, it effectively removes build-up, impurities and unwanted sebum. The Vitamin B6 and Salicylic acid protect and soothe the scalp with their anti-inflammatory benefits.

What Causes Dry Scalp? 

The skin on our scalp is similar to the skin elsewhere on our body and when skin is dry it is absent in oil. On the scalp this will lead to a feeling of tightness, itching and a lack of oils, so the roots won’t really ever look greasy. You may see fine white flakes (unlike the bigger clusters you get with dandruff).

Dry skin is a type you are born with, however there are some factors than can cause your scalp to become excessively dry:

What causes Dry Scalp?

1) HORMONAL CHANGES

During the perimenopause a drop in estrogen can cause scalp itching, while during menopause you could experience a dry scalp and brittle hair.

2) MEDICATIONS

Any medications known to dry out the skin will also cause a dry scalp. These include diuretics, antihistamines, acne medications (roaccutane) and cholesterol medications (statins). Of course, if your doctor prescribes medication it’s best to follow their advice but knowing these medications can have the side effect of causing a dry scalp means you can get ahead of it with the right scalp products.

What Products Can I Use if I Have A Dry Scalp?

With a dry scalp, the main aim is to rehydrate the skin and add much needed nourishment, since your scalp is likely lacking in water and oils.

Bain Riche Dermo-Calm is a hypoallergenic creamy shampoo formulated to target scalp irritation. Its anti-fungal and anti-bacterial so it helps purify the scalp, while leaving the scalp feeling relaxed and supple and your hair feeling moisturised.

Masque Hydra-Apaisant hydrates and soothes a dry scalp. A balancing treatment, it’s a must-try for dry, irritated and itchy scalps, this hero formula also works wonders for those suffering from oily scalps and dandruff.

An exfoliating treatment like Scrub Apaisant is ideal for sensitive and dry scalps. The gel texture gently removes any product build-up or dry flakes.

Lastly, a happy scalp is one with a balanced microbiome, so adding in Potentialiste Serum with its 10% Bifidus Prebiotic helps to feed the good bacteria in the scalp.

How Can I Know If My Scalp Is Healthy?

If you want an expert opinion on your scalp, head to your nearest Kérastase salon. Our in-salon teams are expertly equipped to diagnose your scalp concerns and help advise you on the best products and in-salon treatments.

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