Your head itches after shampooing, under your hat, or in the evening on your pillow. Sometimes there are small flakes, sometimes nothing visible. The first temptation is to buy an anti-dandruff shampoo, but an itchy scalp can have different causes, and for the most common one, dryness, anti-dandruff shampoo is the wrong choice.
In summary
- The three most common cosmetic causes are: dry scalp, dandruff, and sensitive scalp.
- A dry scalp feels tight, flakes very finely, and gets worse with cold weather and harsh washing. Anti-dandruff shampoo does not improve it.
- A sensitive scalp often itches, burns, or stings without visible signs.
- Marked redness, plaques, crusts, hair loss, or itching that does not go away: see a doctor.
Article written by Elisa Avalle, founder of LeLang Skin Care and dermocosmetics specialist. Cover image generated with the support of artificial intelligence.
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Why the scalp itches
The scalp is skin, with a few distinctive features: it is rich in hair follicles and sebaceous glands, has a thin layer of subcutaneous tissue, is densely innervated, and remains covered by hair, which keeps it warm and poorly ventilated. Its surface has a slightly acidic pH, which helps protect it from microorganisms. When this balance is disrupted, because the skin becomes dry, microorganisms increase, or nerve endings become more reactive, the most common sensation is itching.
The dedicated article on skin pH explores the skin's pH and its role in defense.
The three most common situations
| Dry scalp | Dandruff | Sensitive scalp | |
|---|---|---|---|
| What it looks like | Very fine flaking, almost like powder; dull-looking skin | Visible flakes, white or yellowish | Often nothing; sometimes slight redness |
| How it feels | Feels tight, itches after shampooing | Mild to moderate itching | Itching, burning, stinging, discomfort to the touch |
| When it gets worse | Cold, heating, frequent washing, hair dyes | Stress, seasonal changes, humidity | New products, heat, hair dyes, stress |
| What it needs | Gentle cleansing and hydration | Anti-dandruff shampoo | Specific products, few irritating ingredients |
Dry scalp
A dry scalp has the same causes as dryness elsewhere on the skin. There are internal factors, such as a constitutional predisposition, age, certain medications, and a highly restrictive diet. And there are external factors: dry climate, sun, wind, seawater and pool water, frequent washing with highly cleansing shampoos, and repeated coloring and bleaching.
Anti-dandruff shampoo is not the solution for a dry scalp. Its active ingredients target Malassezia and flaking, not the skin barrier: on already dry skin, they can make the situation worse.
What to do
- A gentle shampoo, formulated for frequent use, with mildly degreasing surfactants. You only need a small amount.
- Shampoo only once: the second wash acts on skin that has already been stripped of its lipids and dries it out further.
- Gently massage with your fingertips, without rubbing.
- Conditioner or a mask on the scalp as well, if the formula allows it, with moisturizing and nourishing ingredients such as glycerin, urea, panthenol, ceramides, plant oils, and soothing ingredients such as bisabolol. Leave on for a few minutes, then rinse with lukewarm water.
- Wash your hair less frequently, if possible, and keep the hair dryer about twenty centimeters away, at a moderate temperature.
There are also specific moisturizers for the scalp, to apply before shampooing and leave on. Baby shampoo, often chosen because it is “gentle,” is not the best choice: it is formulated not to irritate young children's eyes, not for an adult's scalp.
The sensitive scalp
Sensitive scalp refers to a condition in which itching, burning, tingling, or tightness occurs in response to stimuli that would not normally cause discomfort: shampoo, heat from a hair dryer, hair dye, or stress. Often, there are no visible signs, which makes the problem difficult to explain. It is not an allergy: you can have sensitive skin without being allergic.
The underlying causes are a less effective barrier and greater reactivity of the nerve endings, which transmit itching and discomfort more easily. Scratching perpetuates the cycle. For general information on sensitive skin, see the guide what sensitive skin is.
What to do
- Choose products specifically formulated for sensitive scalps, with few potentially irritating ingredients and soothing active ingredients.
- Don't over-wash your hair and use lukewarm water, never water that's too hot or too cold.
- After washing or in the evening, a soothing serum for the scalp can provide relief.
- Avoid products containing a lot of alcohol, such as hairsprays and setting sprays, as well as perfume sprayed onto the hair.
- Protect your head from intense sun and cold with a hat.
If you color your hair
Coloring is one of the most delicate steps. Two useful tips: apply it to hair that hasn't been washed for a few days, because sebum partially protects the skin, and protect the hairline with a barrier cream. If swelling, severe burning, blisters, or intense itching also appear on the face and neck after coloring your hair, it could be an allergic reaction: contact your doctor immediately.
When to see a doctor
Itching caused by dryness or sensitivity improves within a few weeks with the right steps. You should see a doctor or dermatologist if:
- the scalp is red, with plaques, crusts, or thick scales;
- the itching disrupts sleep or lasts for more than a few weeks despite changes;
- bald patches or significant hair loss appear;
- the itching appeared after hair dye or a new product, with swelling or blisters;
- the itching also affects other family members, or small dots are visible attached to the hair near the nape of the neck and ears.
Seborrheic dermatitis, psoriasis, contact dermatitis, and head lice can cause an itchy scalp and should be identified and treated by a doctor.
Frequently asked questions
Can a dry scalp turn into dandruff?
These are different conditions, but skin that remains dry and irritated for a long time is more exposed to the development of microorganisms. Treating dryness early is also prevention.
Is it better to wash your hair less often?
If the scalp is dry, yes: once or twice a week, when possible, with a gentle shampoo. If it is oily or has dandruff, washing too infrequently makes the situation worse.
Do oils on the scalp help?
On a dry scalp, an oil used before shampooing can provide comfort. On a scalp with dandruff or seborrheic dermatitis, oils can nourish Malassezia and make it worse.
Can an itchy scalp be caused by stress?
Stress can increase skin reactivity and worsen dandruff and seborrheic dermatitis. It is one factor among others, rarely the only one.
The next step
Before changing products, try to describe the itching: when it appears, whether there are flakes, and whether it worsens after shampooing. With this information, the pharmacist at LeLang partner pharmacies and parapharmacies can help you choose the right products.
Sources for this article
- Bin Saif G.A. et al. (2011). "The itchy scalp: scratching for an explanation". Experimental Dermatology, vol. 20, no. 12, pp. 959-968.
- Misery L. et al. (2008). "Sensitive scalp: does this condition exist? An epidemiological study". Contact Dermatitis, vol. 58, no. 4, pp. 234-238.
- Turner G.A. et al. (2012). "Stratum corneum dysfunction in dandruff". International Journal of Cosmetic Science, vol. 34, no. 4, pp. 298-306.
- Trueb R.M. (2007). "Shampoos: ingredients, efficacy and adverse effects". Journal der Deutschen Dermatologischen Gesellschaft, vol. 5, no. 5, pp. 356-365.
Where to continue: Dry or oily dandruff · Seborrheic dermatitis of the scalp · The skin barrier
