Your skin probably hasn't changed overnight. What's more likely is that your barrier has been wearing down gradually and you've crossed the point where it can't absorb any more — so products you used happily for years start to sting. Less often it's a true contact allergy, which behaves differently and needs a patch test to pin down.
What does "suddenly reacting to everything" actually mean?
Stinging, tightness, burning or itching from products that used to be fine — often with nothing visible to show for it. If the stinging is the main thing you're dealing with, we've written about why a moisturiser stings separately.
Sensitive skin is defined by what you feel, not by what anyone else can see. The international expert group that wrote the definition describes it as unpleasant sensations in response to things that wouldn't normally provoke them.1 There's no blood test, no swab, no scan. If your skin feels like it's reacting, it is — whether or not anyone else can see it.
It's also far more common than it feels when you're in it. A meta-analysis pooling 26 studies across 18 countries and more than 50,000 people found 71% report sensitive skin to some degree, and 40% describe theirs as very or moderately sensitive.2 You are not unusually fragile. You're in the majority.
Is it irritation or an allergy?
Irritation is a dose problem. Allergy is an immune problem. They can feel almost identical and they need completely different handling, which is why getting this right first saves you a lot of time and money.
| Irritation | Allergic contact dermatitis | |
|---|---|---|
| What's happening | The ingredient is directly provoking the skin | Your immune system has learned to recognise an ingredient and reacts to it |
| Who it affects | Anyone, given enough exposure | Only people who've become sensitised to that specific thing |
| Timing | Often within minutes | Typically 12–48 hours after contact |
| Dose | Matters. Less, or less often, is often enough | Doesn't matter. A trace is enough once you're sensitised |
| First time you use it | Can react immediately | No — sensitisation has to happen first |
| How you identify it | Strip back and reintroduce | Patch testing |
| What fixes it | Repair the barrier, reduce the exposure | Avoid the ingredient completely |
The practical difference is the dose column. With irritation, less is often enough — a lower concentration, used less often, on a barrier that's had a chance to recover. With an allergy there's no safe amount, so the only answer is to identify the ingredient and avoid it entirely. Patch testing is the established way to do it, and dermatologists follow a standardised European protocol for exactly this.3
If you're reacting to nearly everything, irritation is the far likelier explanation. Being allergic to many unrelated ingredients at once is uncommon. Having a barrier that's stopped coping, is not.
Why would a product I've used for years suddenly sting?
Three reasons, and all of them are common.
Your barrier has been quietly absorbing the cost. Barrier impairment is one of the recognised features of sensitive skin,4 and it accumulates. Hot showers, a scrub twice a week, an acid on Tuesdays, retinol on Thursdays, a foaming cleanser, a cold snap — none of it is dramatic on its own. Together, over months, it adds up, and a barrier doesn't announce it's running low. It just stops covering for the things it used to cover for.
The product itself has aged. Almost nobody checks this one. Some ingredients change chemically once they've been exposed to air. Fragrance terpenes are the clearest case: linalool and limonene are less allergenic when fresh, but they oxidise on contact with air into compounds that are among the most frequent causes of fragrance contact allergy.5,6 The bottle that's been open on your shelf for 24 months is not chemically the same product you bought. If a long-standing favourite has turned on you, its age is worth considering before your skin is.
You're layering more than you think. Most people underestimate their own routine by two or three steps. Cleanser, toner, essence, serum, eye cream, moisturiser, SPF, and whatever the SPF has in it — every one is a set of ingredients, and they interact. Reacting "to everything" sometimes means reacting to the total, not to any single item in it.
What else changed in the last six weeks?
Work backwards in a process of elimination.
| Worth checking | Why it matters |
|---|---|
| A new product | The obvious one. Include anything you've been given, sampled, or switched to a new formulation of |
| An old product | Open more than 2 years? Oxidation is real and you can't always see it |
| The season | Cold air holds less moisture, indoor heating holds even less. Winter skin behaves differently |
| Your water | Moved house, or moved cities? Hardness varies enormously across Australia |
| Shower temperature | Hot water strips lipids. The hotter the shower, the more it takes |
| Hormonal changes | Pregnancy, perimenopause, stopping or starting hormonal contraception |
| Medication | Several classes affect the skin. Worth raising with whoever prescribed it — never stop anything on your own |
| Sleep, stress, illness | All affect the skin's ability to recover, and all are easy to dismiss |
On water specifically: A population study of infants found higher domestic water hardness associated with increased odds of visible eczema — an adjusted odds ratio of 1.87 in the high-hardness group.7 The research is in babies, not adults, and an association isn't proof of cause. Treat it as a lead worth following if you've recently moved somewhere with hard water, and your skin is noticeably dryer.
How do I work out what's causing it?
Strip back, let things settle, then reintroduce one at a time. It's slow and it's the only method that gives you an honest answer.
- Cut back to the minimum. A gentle cleanser, one simple moisturiser, sunscreen. Nothing active. Nothing with fragrance.
- Give it two weeks. Your barrier needs time, and anything shorter won't tell you much.
- Reintroduce one product. One. Not a routine.
- Patch test it first. Apply a small amount to the same spot — behind the ear or the inner forearm — once or twice a day for five to ten days. Reactions to cosmetic products are sometimes slow, and a single application tells you very little if you haven't reacted immediately.
- Give each new product a fortnight before adding the next.
Yes, it takes a couple of months to get through a full routine this way. Reintroducing three things at once and getting a reaction only takes you back to the start of the process.
When should you see a doctor?
Go, rather than keep experimenting, if any of this applies:
- A rash that's spreading, weeping, blistering or crusting
- Reactions that keep coming back no matter how far you strip the routine
- Skin that's painful rather than uncomfortable
- You suspect an allergy — testing needs a clinic, and it's the only way to get a definite answer
- You take prescribed medication for your skin, or you've recently stopped
A GP or dermatologist can patch test, rule things out, and tell you whether what you're dealing with is a skincare problem at all.
What we use, and why it suits sensitive skin
Short formulas, built around bio-fermented ingredients, with the usual irritants left out.
Fermentation is the reason the ingredient lists can stay short. Probiotic Lactobacillus strains are fermented with plant materials, and the postbiotic that produces is what goes into the formula — so a single ingredient does several jobs that would otherwise need several ingredients. Fewer things on your face means fewer things to react to, and fewer variables when you're trying to work out what has been going wrong.
The exclusions matter just as much as what's included. Nothing from our Possibly Problematic™ list goes in: no fragrance, no dyes, no drying alcohols, no essential oils, no silicones, no parabens, no sulphates. Two of those — fragrance and essential oils — are the ingredients behind the oxidation problem described above.
We always recommend you patch test. Skincare for sensitive skin as very personal and no one formula can work for every single person in the world with sensitive skin, try as hard as we may!
Where to start
Not sure what your skin needs? The Skin Quiz takes 60 seconds and asks about how your skin actually behaves.
Or have a look at the bio-fermented skincare range — made in Australia for skin that reacts to everything, with our six week guarantee.
SKINPOSSIBLE™ is an Australian skincare brand formulating pre-, pro- and postbiotic products for sensitive skin, founded in Melbourne by Jade Williams.
This article is general information about cosmetic skincare and is not medical advice. If your skin is painful, broken or not improving, see a GP or dermatologist. Never stop or change a prescribed medication without speaking to the person who prescribed it.
References
- Misery L, Ständer S, Szepietowski JC, 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. Acta Dermato-Venereologica. 2017;97(1):4–6. doi:10.2340/00015555-2397
- Chen W, Dai R, Li L. The prevalence of self-declared sensitive skin: a systematic review and meta-analysis. Journal of the European Academy of Dermatology and Venereology. 2020;34(8):1779–1788. doi:10.1111/jdv.16166
- Johansen JD, Aalto-Korte K, Agner T, et al. European Society of Contact Dermatitis guideline for diagnostic patch testing. Contact Dermatitis. 2015;73(4):195–221. doi:10.1111/cod.12432
- Misery L, Weisshaar E, Brenaut E, et al. Pathophysiology and management of sensitive skin: position paper from the special interest group on sensitive skin of the International Forum for the Study of Itch (IFSI). Journal of the European Academy of Dermatology and Venereology. 2020;34(2):222–229. doi:10.1111/jdv.16000
- Bråred Christensson J, Andersen KE, Bruze M, et al. Air-oxidized linalool: a frequent cause of fragrance contact allergy. Contact Dermatitis. 2012;67(5):247–259. PMID 22906042
- Karlberg AT, Dooms-Goossens A. Contact allergy to oxidized d-limonene among dermatitis patients. Contact Dermatitis. 1997;36(4):201–206.
- Perkin MR, Craven J, Logan K, et al. Association between domestic water hardness, chlorine, and atopic dermatitis risk in early life: a population-based cross-sectional study. Journal of Allergy and Clinical Immunology. 2016;138(2):509–516. doi:10.1016/j.jaci.2016.03.031
