Guide to dandruff - causes and treatments

Everything You Need To Know About Dandruff: Types, Causes, And Treatments Explained

What exactly is dandruff and why does it happen? Dandruff is a common scalp condition that causes visible flakes, often alongside itching or irritation. It is linked to a combination of Malassezia yeast activity, scalp sebum, individual scalp sensitivity, and faster skin cell turnover, although dryness and other scalp conditions can also cause flaking that looks similar to dandruff.

If you have ever noticed white flakes on your hair, scalp, or favourite black shirt, you are not alone. Understanding what dandruff is, why dandruff occurs, and the difference between oily and dry flakes is the first step towards choosing the right scalp care routine.

This guide explores the common causes of dandruff, dandruff effects, different types of flakes, treatment ingredients, and targeted dandruff treatments that can help maintain a cleaner, healthier-looking scalp.

In this Article

What Is Dandruff?

Dandruff is a scalp condition characterised by visible shedding of scalp skin cells. While skin cells naturally renew and shed, dandruff is associated with abnormal scalp scaling that makes flakes more noticeable on the scalp, hair, and clothing.
Dandruff may appear as loose white flakes or be associated with oilier, more adherent scaling. Some people may also experience itching and scalp discomfort.

Dandruff and seborrhoeic dermatitis are related but should not automatically be treated as identical. Seborrhoeic dermatitis is a more inflammatory condition that can cause scaly patches and inflamed skin and may affect other sebum-rich areas beyond the scalp.

What Causes Dandruff?

The causes of dandruff are multifactorial. Malassezia yeast, scalp oil or sebum, altered skin cell turnover, and individual sensitivity are key factors associated with dandruff development. Dryness, product sensitivity, and underlying inflammatory scalp conditions may also cause or worsen visible flaking. Here are the main factors to understand:

1. Malassezia Yeast

Malassezia is a group of yeasts naturally associated with human skin. Research into dandruff and seborrhoeic dermatitis suggests that interactions between Malassezia and the scalp can contribute to inflammatory and hyper-proliferative responses in susceptible individuals.

This means the presence of yeast alone does not necessarily mean you will develop dandruff. The scalp's individual response also matters.

2. Sebum Overproduction

Sebum is the natural oil produced by sebaceous glands. Malassezia species are lipid-dependent, which means scalp oil can play a role in the scalp environment associated with dandruff. When the scalp is oily, flakes may mix with sebum and remain attached to the scalp rather than falling away as fine, dry flakes.

3. Faster Or Disrupted Skin Cell Turnover

Normally, scalp skin cells renew and shed gradually. With dandruff, this process can become disrupted, making clusters of cells shed as visible flakes.

4. Dry Scalp

A dry scalp can produce fine, loose flakes that may look like dandruff. Cold weather, low humidity, or unsuitable cleansing routines may increase scalp dryness.

However, dry scalp and dandruff are not always the same concern. Understanding the appearance of the flakes and the condition of the scalp can help guide product selection.

5. Seborrhoeic Dermatitis

Seborrhoeic dermatitis is a chronic inflammatory skin condition that commonly affects sebum-rich areas such as the scalp and face. It can cause greasy scaling, redness, and itching.

Persistent oily flakes accompanied by significant inflammation should be assessed by a dermatologist.

6. Sensitivity To Hair Products

Some scalp care or styling products may cause irritation in sensitive individuals. Irritation, redness, and flaking can sometimes resemble dandruff.

If symptoms begin after introducing a new product, discontinue use and assess whether the scalp improves.

In Summary
The main causes of dandruff include Malassezia-related scalp activity, excess sebum, disrupted skin cell turnover, and individual scalp sensitivity. Dryness and inflammatory scalp conditions can also lead to visible flakes, which is why identifying your specific scalp concern is important.

Oily Dandruff Vs Dry Dandruff: What's The Difference?

What's the difference between oily dandruff and regular flakes? Oily dandruff is generally associated with greasy, yellowish, or more adherent flakes on an oily scalp, while dry flakes are usually finer, whiter, and more likely to fall loosely from a dry scalp.

Scalp Concern	Oily Dandruff	Dry Flakes
Flake appearance	Greasy or yellowish	Fine and white
Scalp feel	Oily or greasy	Dry or tight
Flake behaviour	May stick to the scalp	Often falls onto hair or clothing
Associated concerns	Oiliness, itching, possible redness	Dryness, tightness, mild irritation
Care focus	Purifying and targeted anti-dandruff care	Gentle cleansing and scalp comfort

Oily, greasy scaling can be associated with seborrhoeic dermatitis, which affects sebum-rich areas and can cause inflammation.
Dry flakes, on the other hand, may result from a dry scalp rather than classic dandruff. This is why oily dandruff vs dry dandruff should be considered before choosing a shampoo.

In Summary
Oily dandruff tends to appear as greasy or adherent flakes alongside excess sebum, while dry scalp flakes are usually smaller, lighter, and associated with dryness or tightness. If you cannot identify your scalp concern or symptoms persist, seek professional assessment.

What Are The Symptoms And Effects Of Dandruff?

Dandruff symptoms can vary from person to person. Common signs include:

1. Visible White Or Yellow Flakes

Flakes may appear on the scalp, through the hair, or on clothing.

2. Itching And Irritation

Dandruff can cause an itchy scalp. Frequent scratching may increase irritation and scalp discomfort.

3. Redness Or Inflammation

More inflammatory scalp conditions, including seborrhoeic dermatitis, may cause visible redness and scaly patches.

4. Oily Scalp

Some people experience flakes alongside excess scalp oil, particularly when greasy scaling is present.

5. Impact On Hair And Scalp Comfort

The dandruff effects may extend beyond visible flakes. Persistent itching and scratching can increase scalp discomfort and may contribute to hair breakage from mechanical friction.

6. Impact On Confidence

Visible flakes can make some people feel self-conscious, especially when dandruff is noticeable on dark hair or clothing.

In Summary
Common dandruff effects include visible flakes, itching, irritation, and scalp discomfort. Identifying symptoms early and following a targeted scalp care routine can help manage flakes and maintain scalp comfort.

What Is Dandruff Treatment - What Actually Works?

What is an anti-dandruff treatment? Anti-dandruff treatment uses targeted cleansing or scalp-care ingredients to address factors associated with flakes, such as fungal activity, excess scaling, and buildup. Common anti-dandruff actives include piroctone olamine, zinc pyrithione, salicylic acid, and selenium sulfide. Here's how commonly used ingredients work:

1. Piroctone Olamine

Piroctone olamine is an anti-dandruff active with antifungal activity. Research has examined its action against Malassezia species, while newer mechanistic research describes its ability to interfere with fungal metabolism through iron chelation. The Kérastase Symbiose range uses Piroctone Olamine to help act on dandruff formation and yeast proliferation.

2. Salicylic Acid

Salicylic acid is used for its exfoliating or keratolytic action. In scalp care, it can help loosen and dissolve accumulated flakes, supporting a cleaner scalp surface. The Kérastase Symbiose range combines Salicylic Acid with Piroctone Olamine in targeted anti-dandruff formulas.

3. Zinc Pyrithione

Zinc pyrithione has historically been used in anti-dandruff treatments. A peer-reviewed dandruff review reports that it may influence scalp keratinisation and sebum processes and reduce Malassezia populations.

4. Selenium Sulfide

Selenium sulfide is another ingredient used in medicated dandruff care. Research has compared selenium-based shampoos with other anti-dandruff actives for seborrhoeic dermatitis management.

Which Ingredient Should You Choose?

The right treatment depends on your scalp concern. Flake buildup may benefit from exfoliating ingredients such as Salicylic Acid, while dandruff associated with Malassezia activity may require an antifungal-focused approach.

Persistent or severe symptoms should be evaluated by a dermatologist, particularly because psoriasis, eczema, and seborrhoeic dermatitis can resemble or overlap with dandruff symptoms.

In Summary
Effective dandruff treatments should be selected according to the type of flakes and scalp condition. Targeted ingredients such as Piroctone Olamine and Salicylic Acid can help address dandruff formation and accumulated flakes, while consistent scalp care is important for maintaining results.

How To Treat Dandruff: A Step-By-Step Routine

If you want to know how to manage dandruff, follow a consistent routine rather than switching products after only a few washes.

Step 1: Identify Your Flake Type

Check whether your scalp is oily with adherent flakes or dry and tight with fine, loose flakes. This helps distinguish oily dandruff vs dry dandruff and guides your routine.

Step 2: Choose A Targeted Anti-Dandruff Shampoo

Use an anti-dandruff shampoo suited to your scalp type. For example, if you have a dry, sensitive scalp prone to dandruff, go for the Kérastase Symbiose moisturizing anti-dandruff cellular shampoo that combines ingredients to target dandruff while offering moisturizing care. On the other hand, if you’re the one with an oily, sensitive scalp prone to dandruff, try the Kérastase Symbiose purifying anti-dandruff cellular shampoo to remove dandruff while preventing oil buildup.

Step 3: Massage The Scalp Gently

Apply shampoo to wet hair and focus on the scalp. Massage gently using your fingertips rather than scratching with your nails.

Step 4: Add A Targeted Scalp Treatment

Pair your cleansing routine with a suitable anti-dandruff scalp treatment. The Symbiose range includes a targeted anti-dandruff serum for scalps built around Piroctone Olamine, Salicylic Acid, and Bifidus Extract to eliminate dandruff and prevent reoccurrence.

Step 5: Maintain Regular Scalp Cleansing

Wash according to your scalp's oiliness and product needs. Allowing excessive oil, sweat, and styling residue to accumulate may make scalp discomfort and visible flakes harder to manage.

Step 6: Avoid Excessive Scratching

Scratching can worsen irritation. Instead, focus on targeted cleansing and scalp care.

Step 7: Monitor Your Scalp

If your dandruff remains persistent, becomes painful, or is accompanied by significant inflammation or thick scaling, consult a dermatologist.

In Summary
A consistent anti-dandruff routine includes identifying your scalp type, using targeted shampoo, applying suitable scalp care, and avoiding excessive scratching. If symptoms do not improve, professional assessment can help rule out other scalp conditions.

When Should You See A Dermatologist?

Dandruff is often manageable with consistent scalp care, but not every flaky scalp is simply dandruff. Consult a dermatologist if you experience severe redness, painful irritation, thick or silvery scales, sores, significant hair shedding, or symptoms that persist despite appropriate anti-dandruff care. Conditions such as psoriasis, eczema, and seborrhoeic dermatitis may require medical diagnosis and treatment.

Ultimately, understanding why dandruff occurs makes it easier to build a more targeted routine. Dandruff is influenced by scalp oil, microorganisms such as Malassezia, skin cell turnover, and individual scalp sensitivity. The right approach combines regular cleansing with ingredients selected for your specific flake and scalp type.
Explore the Kérastase hair care products that include targeted anti-dandruff hair and scalp care. You can also use the Kérastase Hair Quiz to discover a routine suited to your hair and scalp concerns.