The skin barrier and sensitive skin: why everything irritates you and how it is repaired

“Sensitive skin” is a syndrome defined by what is felt. The international consensus definition puts it this way: the occurrence of unpleasant sensations — stinging, burning, pain, itching, tingling — in response to stimuli that should not normally provoke them, and which are not explained by lesions attributable to any skin disease. The skin may look normal or show erythema. That is: it is defined by the sensation, not by the lesion, and it affects far more people than think they have it.

And here is the nuance almost nobody publishes: barrier disruption frequently accompanies sensitive skin, but it is not established as its cause. The position paper that reviewed the pathophysiology concludes that sensitive skin is not an immune disorder but that it is related to alterations of the skin’s nervous system, and that barrier abnormalities “are frequently associated, but there is no direct causal relationship”.

What is certain, checkable and actionable tonight is that the barrier can be broken from outside, that the chief suspect is at the washbasin, and that the intervention with the most mileage in it consists of taking away, not adding.

It is part of the dermocosmetics cluster, and it is the page the others point to when something has irritated the skin.

What sensitive skin actually is

In 2017, the sensitive skin working group of the International Forum for the Study of Itch set a consensus definition by the Delphi method:

A syndrome defined by the occurrence of unpleasant sensations — stinging, burning, pain, pruritus and tingling — in response to stimuli that normally should not provoke such sensations. These unpleasant sensations cannot be explained by lesions attributable to any skin disease. The skin can appear normal or be accompanied by erythema. It can affect any body location, especially the face.

Three consequences follow from that, and they change how everything else is approached:

1. It is a diagnosis of exclusion. If there is a lesion, it is something else. And that something else — rosacea, atopic dermatitis, contact dermatitis, seborrhoeic dermatitis — has its own management.
2. It is not measured with an instrument, it is described. That is why the studies talk about “self-declared sensitive skin”.
3. It is not rare. The 2020 meta-analysis of 26 studies, 18 countries and 51,783 individuals found a pooled prevalence of 71% (95% CI 62-81%) for some degree, and 40% (95% CI 32-47%) for moderate or very high sensitivity. It affects women (45%) and men (33%), with a higher risk in women (RR 1.741; 95% CI 1.38-2.20). In Europe, 44%.

The nuance that has to be stated

The same group’s 2020 position paper reviewed the pathophysiology and reached conclusions worth reproducing unsoftened: sensitive skin is not an immune disorder but is related to alterations of the cutaneous nervous system; barrier abnormalities are frequently associated but with no direct causal relationship demonstrated; and to date there is no clinical trial supporting the use of topical or systemic drugs in sensitive skin, nor sufficient data to reach a management consensus. They recommend avoiding triggers, using well-tolerated cosmetics and a personalised approach that also takes psychosocial factors into account.

🔑 Translated: nobody has the treatment for sensitive skin. What is known is what makes it worse, and that can be taken away.

The barrier: what it is and what breaks it

The stratum corneum works like a wall. The bricks are the corneocytes — cells with no nucleus left, loaded with keratin — and the mortar is an ordered mixture of ceramides, cholesterol and free fatty acids. The wall holds water in and keeps irritants, allergens and micro-organisms out. When the mortar fails, water is lost — measured as transepidermal water loss, TEWL — and what should not get in, gets in.

On top of that wall there is an acid mantle: the surface of healthy skin sits at around pH 4.5-5.5. And that detail, which sounds cosmetic, turned out to be a mechanism.

Why pH decides

Two papers in the Journal of Investigative Dermatology demonstrated it with a clean design: instead of using water or soap — which introduce other variables — they applied chemical superbases to raise the pH of the stratum corneum in isolation, without changing hydration.

• In the short term (2003): raising the pH disrupted barrier homeostasis and the integrity and cohesion of the stratum corneum. The cause was the rapid activation — within under 20 minutes — of serine proteases, which degraded the corneodesmosomes, the junctions that hold the cells together. The degradation of desmoglein 1 was confirmed. When inhibitors of those proteases were applied along with the base, integrity returned to normal.
• Sustained (2005): prolonged neutralisation disrupted not only barrier recovery but its baseline function, because the sustained activity of those proteases degraded the lipid-processing enzymes — β-glucocerebrosidase and acid sphingomyelinase — that is, the ones that make the mortar. Again, protease inhibitors normalised the picture.

⚠️ These are experimental studies on hairless mouse skin using superbases, not soap, and that is how they should be read: they establish the mechanism, they do not quantify the damage done by a particular product. But they explain why the pH of what you put on your face is not a whim of the label.

The short list of what breaks a barrier

• Over-cleansing, or cleansing with the wrong product. It is the leading cause and has a section of its own.
• Over-exfoliating. It is set out in exfoliating acids at home: the sign is skin that shines and feels tight at the same time.
• Starting several actives at once, typically retinol plus an acid plus vitamin C in the same week.
• Very hot water and friction — towels, brushes, sponges.
• Cold, wind and central heating, which lower the ambient humidity.
• Fragrance and some preservatives, on predisposed skin.
• Recent medical treatments: laser, peels, pulsed light. There the barrier is deliberately disrupted and the care is different, as in recovery after CO₂ laser.

The cleanser: the product that does the most damage and gets looked at least

It is the blind spot of almost every routine. A cleanser is used once or twice a day, comes into contact with the whole face and is chosen on price or on lather.

A 2024 study measured the pH of 250 commercial cleansers: 37 soaps (32 bars, 5 liquids) and 213 syndets — synthetic detergents — (14 bars, 199 liquids). The results:

The full range ran from pH 3.59 to 10.83. And the figure that matters most to the buyer:

🚨 The pH was not declared on any of the 37 soaps, and on only 15% of the syndets. Among those labelled “balanced”, the measurement came out neutral on some and alkaline on others. The label is not enough.

What to do with that

• If the skin is irritated, a bar of soap is not an option. Not for marketing reasons: because every one analysed was highly alkaline.
• A liquid syndet-type cleanser has an ~85% chance of being acidic, which is what you want. It is the reasonable default bet.
• Once a day is enough if there is no make-up or sunscreen to remove. The morning wash, with water, is enough for a lot of people.
• No friction and with lukewarm water, never hot.
• 🔑 And if the manufacturer declares the pH, that is a good sign in itself: it means they have measured it and stand by the figure. It is the most useful question you can ask at a counter, and one of the ones we answer with the product sheet in front of us.

How it is repaired: take away, don’t add

This is the part no catalogue writes, because the treatment consists of not buying anything for a month.

The typical spiral: the skin feels tight → a new soothing product is bought → cleansing twice a day and exfoliating continue → a repair serum is added on top → it gets worse. Every step adds a product and none removes the cause.

The rescue protocol, four to eight weeks:

1. Out with everything active. Acids, retinoids, acidic vitamin C, mechanical exfoliants, toners with alcohol, masks. All of it.
2. One gentle cleanser, and at most once a day. See the previous section.
3. A repairing moisturiser, morning and night. Ideally with the kind of lipids that are missing — ceramides, cholesterol, fatty acids — and with humectants that hold water.
4. Sunscreen during the day, which is the one thing kept whatever happens. How to choose it, in how to choose a sunscreen.
5. Nothing else. No “soothing” serum, no oil, no new treatment. The list is three products because the whole point is that it is three.

When it shows, as a rough guide and with wide variation between people: at around two weeks the stinging stops, at around four the redness settles, and at around eight tolerance returns for products that used to be uncomfortable.

🚨 And afterwards, one at a time. Reintroduction is where everything gained gets lost: you go back with a single active, at the lowest frequency, and wait two weeks before adding the next. It is the same stepped logic as how to start with retinol.

What to add once it stops hurting

With the prior warning that the management evidence is limited — the position paper says so itself — these are the components with most mileage in a repair moisturiser:

• Physiologic lipids: ceramides, cholesterol and fatty acids. They are literally the material missing from the mortar. It is the most logical approach and the most studied.
• Humectants: glycerin, hyaluronic acid, low-concentration urea, panthenol. They hold water in the corneum. Glycerin is among the oldest and best documented.
• Light occlusives, which slow water loss while the barrier rebuilds itself.
• Niacinamide, well tolerated and with a described effect on barrier function.
• Colloidal oatmeal and other soothing agents for the itch, with more modest evidence.

⚠️ What to avoid while it repairs: fragrance, denatured alcohol, acids, retinoids, essential oils and textures that need rubbing to spread.

🔑 Texture matters more than it seems: on dry skin a cream works better; on irritated oily skin, a fluid emulsion. Skin can be oily and have a broken barrier at the same time, and that is a frequent case in anyone who has spent months treating acne on their own.

What is not sensitive skin

This is the part that makes this page useful rather than a brochure. If any of these appears, it is not sensitivity: it is a diagnosis, and it deserves a consultation.

• 🚨 Persistent redness on the cheeks and nose, with flare-ups, flushing, papules or visible vessels. That points to rosacea, which has its own management and light-based options described in IPL for redness, rosacea and telangiectasia.
• 🚨 Dry, itchy patches, in the flexures or recurring, with a personal or family history of atopy.
• 🚨 Redness that always appears in the same place and with the same product, or that spreads with defined borders: it may be contact dermatitis and sometimes needs patch testing.
• 🚨 Greasy flaking in the nasal folds, eyebrows or scalp.
• 🚨 Swollen eyelids, blisters, crusting or any lesion that bleeds.

⚠️ None of these is treated with a cosmetic, and this page deliberately gives no regimen for any of them.

Frequently asked questions

How do I know if my barrier is damaged?

The typical signs are skin that feels tight after washing, that stings or itches with products it used to tolerate, that reddens easily, and a moisturiser that “absorbs instantly” without the tightness going away. There is often shine and dryness at the same time. If there are lesions — patches, papules, vesicles — the explanation is something else and it needs looking at.

Does sensitive skin get cured?

Sensitivity as a trait is not “cured”, but the episodes do improve. What comes back is tolerance: the irritants are withdrawn, the barrier rebuilds over weeks and many products that used to be uncomfortable become usable again. What does not exist, as of today, is a drug with trials supporting its use in sensitive skin as such.

Is it better to cleanse once or twice a day?

It depends on what there is to remove. If you wear make-up or sunscreen during the day, a wash at night is needed. In the morning, water is enough for many people. If the barrier is damaged, once a day is the prudent choice.

Does tap water spoil the skin?

Very hard water can contribute to dryness and to the feeling of tightness, although it weighs far less than the product used and the temperature. Before considering a water softener it is worth turning the water temperature down and reviewing the cleanser.

Can I use retinol if I have sensitive skin?

Once the barrier is repaired, yes, with very slow introduction. While it is irritated, no: that is wasting the product and prolonging the problem. The schedule is on the page about how to start with retinol.

Do products “for sensitive skin” work?

They work to the extent that they leave out irritants — fragrance, alcohol, acids — which is what genuinely helps. The label is not regulated as a category with requirements, so what you have to look at is the ingredients list, not the claim on the front of the pack.

And if it happens after a laser or a peel?

There the barrier is disrupted in an expected and controlled way, and the care is set by the team that carried out the treatment. You do not apply this page’s protocol off your own bat: you follow the one for the procedure, as in recovery after CO₂ laser.

Sources

• Misery L, et al. Definition of Sensitive Skin: An Expert Position Paper from the Special Interest Group on Sensitive Skin of the International Forum for the Study of Itch (IFSI). Acta Dermato-Venereologica, 2017. PMID 26939643. — Consensus definition by the Delphi method: “A syndrome defined by the occurrence of unpleasant sensations (stinging, burning, pain, pruritus and tingling) in response to stimuli that normally should not provoke such sensations. These unpleasant sensations cannot be explained by lesions attributable to any skin disease. The skin can appear normal or be accompanied by erythema. Sensitive skin can affect all body locations, especially the face.”
• Misery L, et al. Pathophysiology and management of sensitive skin: position paper from the special interest group on sensitive skin of the IFSI. Journal of the European Academy of Dermatology and Venereology, 2020. PMID 31660659. — 🔑 Verbatim: sensitive skin is not an immune disorder but is related to alterations of the cutaneous nervous system; barrier abnormalities are frequently associated but there is no direct causal relationship; to date there is no clinical trial supporting the use of topical or systemic drugs in sensitive skin and the published data are not enough for a management consensus. They recommend avoiding triggers, using well-tolerated cosmetics and a personalised approach taking in biomedical, neural and psychosocial factors.
• Chen W, et al. The prevalence of self-declared sensitive skin: a systematic review and meta-analysis. Journal of the European Academy of Dermatology and Venereology, 2020. PMID 31869523. — 26 studies, general population in 18 countries, 51,783 individuals. Pooled prevalence of some degree of sensitive skin: 71% (95% CI 62-81%); moderate or very high sensitivity: 40% (95% CI 32-47%). Women 45% (36-55%), men 33% (24-42%); relative risk in women 1.741 (95% CI 1.38-2.20). By region: Europe 44% (39-50%), North America 38%, South America 35%, Asia 31%. ⚠️ Self-declared prevalence, with the heterogeneity that implies.
• Hachem JP, Crumrine D, Fluhr J, Brown BE, Feingold KR, Elias PM. pH directly regulates epidermal permeability barrier homeostasis, and stratum corneum integrity/cohesion. Journal of Investigative Dermatology, 2003. PMID 12880427. — To separate the effect of pH from that of hydration, two chemically unrelated superbases were applied to hairless mouse skin. The rise in surface pH ran in parallel with disruption of barrier homeostasis and of stratum corneum integrity and cohesion, attributable to the rapid activation (< 20 min) of serine proteases and the consequent degradation of corneodesmosomes; western blot confirmed the degradation of desmoglein 1. Co-application of serine protease inhibitors normalised stratum corneum integrity. ⚠️ An animal model with superbases, not soap: it establishes the mechanism, it does not quantify the damage done by a commercial product.
• Hachem JP, et al. Sustained serine proteases activity by prolonged increase in pH leads to degradation of lipid processing enzymes and profound alterations of barrier function and stratum corneum integrity. Journal of Investigative Dermatology, 2005. PMID 16117792. — Sustained neutralisation of the stratum corneum disrupted not only the kinetics of recovery but baseline barrier function, through reduced activity and degradation of β-glucocerebrosidase and acid sphingomyelinase — the enzymes that process the barrier’s lipids — as a consequence of sustained serine protease activity. Protease inhibitors normalised enzyme activity and content. ⚠️ The same experimental model.
• Not all marketed skin cleansers’ pH is optimal for atopic dermatitis. Allergy and Asthma Proceedings, 2024. PMID 38982600. — The pH of 250 products was measured (10% solutions, pH meter): 37 soaps (32 bars, 5 liquids) and 213 syndets (14 bars, 199 liquids). Full range 3.59-10.83. All 37 soaps came out highly alkaline. Syndet bars: 6 neutral, 8 alkaline, none acidic. Liquid syndets: 84.9% acidic, 11.1% neutral, 4.0% alkaline. 🚨 The pH was not declared on any of the 37 soaps and on only 32 syndets (15%); among those labelled “balanced”, the measurement came out neutral on some and alkaline on others. ⚠️ The study is framed around atopic dermatitis; the finding on pH and labelling applies to any irritated skin.

Book your consultation

If you have spent months trying products “for sensitive skin” and each one lasts you a fortnight, the problem is almost never the one that is missing: it is one of the ones you already use. Going through the whole routine — cleanser included, which is the one nobody looks at — and staying on three products for a month costs nothing and works in most cases. If there is also persistent redness or flare-ups, it is worth having it looked at before buying anything else. You can see the cleansing and repair products we work with in the barrier, hydration and cleansing shop.

Clinical confirmation by the surgeon

Dr Enrique Salmerón González

Specialist in Plastic, Aesthetic and Reconstructive Surgery
Registration no. 46/4624077

Dr Elena García Vilariño

Specialist in Plastic, Aesthetic and Reconstructive Surgery
Registration no. 46/4624503

Last reviewed: 17 September 2026. This content is for information only and does not replace an individual assessment by a healthcare professional.