What Causes Eczema Flare-Ups? The 10 Triggers I Wish I’d Known About Sooner

Eczema flare-ups happen when an already-fragile skin barrier comes up against something it simply can’t handle. The 10 most common triggers I hear about again and again from my customers are: dry air (hello winter office heaters), change of season, heat and sweat, detergents, fragranced skincare, stress, certain fabrics (wool and polyester school and sports uniforms are a common one), food, hormonal shifts and environmental allergens like dust mites and pollen.

Most people don’t react to one thing. They react to a stack. When I identified my daughter’s top three (dust mites, fragranced skincare and stress) it significantly reduced her flare frequency.

If you only have two minutes, that’s the answer. If you want to actually understand why this keeps happening to you or your child, keep reading. It might save you a lot of future flare stress.

Why I wrote this (and why I’m qualified to)

I’m Jacqui. I started Salvida after my daughter’s eczema spiralled out of control in Singapore. We did the rounds. Multiple doctors and derms, escalating steroid potencies (hello mum-guilt!), antibiotics for the infections that kept breaking through. For the first time in 10 years her eczema was ‘unmanageable’. Doctors were happy to prescribe but no one was telling me why this was happening.

I’m not a doctor. I’m a skin nerd who fell down the rabbit hole because I had to. What I learned (the slow, painful way) is that almost nobody talks about triggers in a useful way. You get a list of things to avoid and sweeping generalisations, but that’s not advice. That’s like throwing a whole bunch of stuff at a wall and hoping something sticks.

So this is the article I needed back then, when I was feeling frustrated, lost and helpless. The 10 triggers, what each one actually does to the skin, and how to figure out which ones are uniquely yours.

First, what’s happening in skin during a flare?

Eczema-prone skin is characterised by a compromised barrier. The outermost layer (the stratum corneum) is like a brick wall, with skin cells as the bricks and lipids (ceramides, cholesterol, fatty acids) as the mortar. In eczema, the mortar is weak and patchy. Water escapes. Irritants get in.

When a trigger reaches that under-protected skin, the immune system overreacts. You get the cascade most of us know too well: redness, itch, dryness, sometimes weeping, sometimes thickening (the medical term is lichenification, or what most eczema parents just call elephant skin) if it’s been going on a while.

This is the bit that matters: the trigger isn’t really the problem. The barrier is. Reduce the barrier dysfunction and the same trigger that used to set off a flare often stops causing one. Using the right barrier-supporting skincare and working with a naturopath on your gut health is the closest thing to control most of us will get.

For more on barrier function, that’s a whole other article, one that I’m going to start mapping out right after this. For now, just know: barrier first, trigger second.

The 10 most common eczema flare-up triggers

1. Dry air and change of season

The biggest one. Cold air outside, dry heating inside, low humidity, or a sudden swing between the two will pull water out of compromised skin faster than it can be replaced. This is why so many Aussie eczema sufferers get worse the moment the heater goes on in May (Winter Eczema - The Aussie Survival Guide for more information), and why long-haul flights are a special kind of hell.

What helps: a humidifier in the bedroom (aim for 40 to 60% humidity) and a thicker occlusive barrier balm at night, preferably applied within three minutes of getting out of the shower.

2. Heat and sweat

Sweat contains sodium, urea and trace minerals that sting compromised skin and disrupt the microbiome. Hot showers, summer heatwaves, exercise, even being under heavy bedding can trigger an itch-scratch cycle.

What helps: lukewarm water only, patting (not rubbing) sweat off the skin as soon as you can, breathable cotton or bamboo layers, a quick rinse after a workout. Bodyguard is the cream I use after sweat-heavy days because it layers well on damp skin without feeling heavy.

3. Detergents and soaps

Sodium lauryl sulfate (SLS), sodium laureth sulfate (SLES) and traditional bar soap will strip the lipids out of an eczema barrier in one wash. So will most laundry powders, dishwashing liquids and commercial hand soaps.

What helps: swap to a sulfate-free, fragrance-free wash. Wear gloves to do dishes. Run an extra rinse cycle on your laundry, or switch to a gentle, additive-free detergent like Barekin. This is the single fastest change most people can make.

4. Fragrance in skincare (the silent flare-er)

Fragrance is the most common contact allergen in the world. “Parfum” or “fragrance” on an ingredient list can mean any one of more than 3,000 compounds, and brands aren’t required to disclose which. Essential oils count too. Lavender and tea tree are notorious eczema triggers despite their wellness halo.

What helps: read every label. Fragrance-free isn’t the same as unscented (unscented products often contain masking fragrance). If you’ve never done a full audit of your bathroom, you’ll be shocked by what’s in there. Especially in products aimed at babies and children.

5. Stress

Stress doesn’t cause eczema, but it absolutely triggers flares. Cortisol, the body’s main stress hormone, suppresses the immune system in some ways and inflames it in others. The end result is more barrier disruption, more itch sensitivity, more scratching at 2am. I’ve witnessed this myself with my own daughter. If we fight, she starts itching. It’s spooky how immediate her reaction is.

What helps: I know “manage your stress” is the most useless advice in the world when your kid’s been awake for four nights, but even small things compound. Sleep when you can. Move your body. Get outside. If you’re in the middle of something genuinely hard, a flare is not a personal failure. It’s your body communicating with you.

6. Certain fabrics

Wool is the worst offender (the fibres are mechanically scratchy and many people are also allergic to lanolin). Polyester and nylon trap heat and sweat. Even “soft” fabrics with rough seams or stiff tags can set off a flare.

What helps: cotton and bamboo against the skin. Wash new clothes before wearing. Cut tags out. For kids, look for flat seams and consider eczema-friendly sleepwear. If they’re playing winter sports, consider cotton or bamboo undershirts, vests or leggings under the uniform.

7. Food

Food can be a real trigger, but it’s a deeply individual one and it’s often the first thing people cut when it shouldn’t be. Around 10 to 30% of children with moderate-to-severe atopic dermatitis have a food allergy that genuinely contributes to flares. In adults, that figure is much lower. For everyone else, food isn’t the primary driver, even though it gets blamed first because it feels controllable.

The common culprits if you do have a food trigger: cow’s milk dairy, eggs, soy, wheat, peanuts, tree nuts. For some people, histamine-rich foods (aged cheese, fermented foods, tomatoes, alcohol) make itch worse (although that doesn’t necessarily mean you’re allergic to those foods).

I’ve found that food comes into play more when you’re working alongside a health professional like a naturopath on improving gut health. Food is still a big part of the puzzle, but rather than thinking about it as a trigger (“this food caused me to flare”) think of it like a tool (“I can support my body and gut health by including ‘x’ food in my diet daily”).

What helps: don’t cut out food groups without medical guidance, especially for kids. Restrictive eating in children can cause growth issues and, counterintuitively, increase the risk of developing food allergies. If you suspect food is a trigger, see an allergist or paediatric dietitian. A two-week food diary with photos of the skin alongside it is far more useful than guessing.

8. Hormonal shifts

Many women notice flares around their period, during or post pregnancy or in perimenopause. Oestrogen, progesterone and testosterone all influence skin barrier function and immune response. Hormonal eczema often shows up on the eyelids, neck and hands first.

What helps: tracking your cycle alongside your skin for two or three months. If there’s a clear pattern, you can pre-empt by being more diligent with barrier care in the week before.

9. Dust mites, pollen and pet dander

Around 80% of people with atopic dermatitis test positive for at least one environmental allergen. Dust mites are the biggest one in Australia, especially in coastal cities with high humidity. Pollen flares are seasonal. Pet dander is sneaky because it sticks to clothes and furniture even when the animal isn’t in the room. All three of these were main triggers for my daughter, which is why her eczema flared so severely in Singapore. Hot weather plus high humidity equals an environment in which dust mites thrive.

What helps: hot-wash bedding weekly (60°C kills mites), allergen-proof pillow and mattress covers, vacuum with a HEPA filter, dust with a damp cloth rather than dry, and during pollen season dry all washing (bedding included) indoors. For severe environmental allergy, immunotherapy is worth talking to an immunologist about.

10. Infections (the trigger nobody talks about)

Eczema-prone skin is colonised by Staphylococcus aureus at much higher rates than healthy skin. When the barrier is compromised, that bacterial load tips into infection, which then drives more inflammation and the flare cycle rolls on. This is the loop that kept my daughter on antibiotics for so long.

Signs of infection: yellow crusting, weeping, sudden worsening that doesn’t respond to your usual routine, fever.

What helps: see a doctor. Antimicrobial bleach baths (highly diluted, 1/4 cup of household bleach per full bath of water, twice a week) are recommended by The Royal Children’s Hospital. Don’t do this without checking with your doctor first, especially for young kids.

Why most people are looking in the wrong place

When I ask customers what they think is causing their flares, 80% say “food” or “stress.” Both can be real triggers. But the actual most-common drivers I see, by a long way, are detergents, fragrance and barrier neglect.

People look at food first because it feels controllable. You can’t cut out the weather, but you can cut out dairy. The problem is, you can spend two years on a restricted diet that does nothing while the real trigger (your laundry powder, your shower temperature, your “natural” body wash with lavender) continues to slowly affect your barrier.

The trigger journal: how to actually find your pattern

This is the most boring piece of advice in the world and the only one that works. For two weeks:

• Take a daily photo of your worst-affected area in the same light.
• Note three things in your phone: what you ate, what the weather did, and any product you used (skincare, laundry, household).
• Add a 1 to 10 itch score.

After 14 days, lay them out together. Patterns appear that you’d never spot in real time. I’ve had customers email me saying they’d identified their fabric softener as the culprit in week one. Others realised their “gentle moisturiser” was the problem the whole time.

If you’re managing eczema for a young child, do this for them. Most paediatricians will take a trigger journal seriously in a way they won’t take a verbal “I think it’s stress / dairy.”

Free printable downloads. The Skin-ED Trigger Journal and the Skin-ED Food Diary. Both are Word documents. Print, fill in and share with your doctor. (COMING SOON)

What to do when a flare hits (the barrier-first approach)

When a flare starts, the instinct is to reach for the strongest steroid you have. That works short-term. The problem is, the underlying barrier is still broken, so the trigger keeps winning.

The is the approach that worked for me and my daughter:

• Stop everything except barrier-first skincare like Barrier NPR+. No actives. No exfoliants. No fragrance. Just a thick, zinc-rich cream applied generously, two to three times a day.
• Apply within three minutes of any water contact. Skin loses moisture fast once it’s out of the shower, and dermatologists describe a three-minute window where the right cream traps that moisture in.
• Sleep in cotton, or nothing at all. Anything that isn’t synthetic. Run a humidifier, drop the shower temperature.
• You’re best placed to know whether to continue using prescribed topical steroids. If you decide to continue, use only as directed and ideally only on actively inflamed areas and only for as long as you need.
• If you’re not seeing improvement in seven days, see a doctor. Bacterial infection is far more common than people realise.

Barrier NPR+ is the cream I formulated with my daughter in mind. The hero ingredients are zinc (for barrier protection), colloidal oatmeal (which helps soothe itch and rough, bumpy skin), sweet almond oil and ceramides. No fragrance, no essential oils, suitable for eczema-prone skin and also for your baby once they’re eating varied solids. [Read more about Barrier NPR+ here].

Don’t forget that the most important time to take care of your skin is when it’s not actively flaring. Whilst flares get more attention, it’s a consistent daily routine when your skin is calm that will help break or delay the flare cycle. Bodyguard, our water-based moisturiser with pre and postbiotics is the product for skin in recovery.

It’s not a treatment. It’s the boring “daily maintenance” part of a care program that gives your skin a fighting chance.

When to see a doctor

This piece is education, not medical advice. Please see a GP or dermatologist if:

• Your eczema is weeping, crusting yellow or smells off (likely infection).
• You’ve had a flare for more than two weeks that isn’t improving with basic barrier care.
• The itch is interfering with sleep, work or your child’s school.
• You’re climbing topical steroid potency without a clear plan.
• You suspect a food allergy (especially in babies).

Eczema is manageable, but it’s also individual. A good naturopath who understands barrier-first care is worth their weight in gold.

What about gut health?

It’s my personal opinion that gut health is a cause, not a trigger. I don’t like making sweeping statements, but I do believe that real long-term progress often comes when people look at their gut alongside their skin. The science on the gut-skin axis is moving quickly, and the lived experience of every eczema family I’ve spoken to backs it up.

This topic deserves its own article, so please stay tuned.

Further reading (guides that helped me figure this out)

I’m not a doctor and I’m not pretending to be. Everything in this article is what I learned the hard way, cross-checked against the research, and put through the lens of running a skincare brand for sensitive skin. If you want to dig deeper, here are some of the reference guides that helped me with my own understanding. Bookmark the ones that speak to you.

• Eczema triggers and causes, National Eczema Association. The most thorough trigger breakdown I’ve found. US-focused but globally relevant.
• Eczema (atopic dermatitis) fact sheet, Royal Children’s Hospital Melbourne. The Aussie gold standard for paediatric eczema. I send this link to friends with newly-diagnosed kids.
• Eczema Support Australia. Local community, advice line, free resources. They’ve helped more Aussie families than they get credit for. Worth donating to if you can.
• 2023 AAAAI/ACAAI Joint Task Force Atopic Dermatitis Guidelines (dietary elimination supplement). The peak allergy bodies on elimination diets. Heavier reading but worth it if food is on your mind.
• Topical Steroid Withdrawal diagnostic criteria, NIH (2023). For anyone wondering if they might be in TSW, this is the most recent formal definition.
• Hard water and atopic eczema in infants, King’s College London. The study that first connected hard water to higher infant eczema rates.

What I’d read next

Skin-ED: Winter Eczema: The Aussie Survival Guide. 

For everything else on barrier-first skincare, gentle ingredients and life with sensitive skin, browse the rest of Skin-ED here.

One last thing

If you take one thing from this article, let it be this: you are not failing. Eczema is loud and exhausting and stubborn, and figuring out your triggers is detective work that takes months, not days. Or in my case years, and that’s despite my own chronic eczema history. Be patient with your skin. Be generous with the right skincare. Be kind to the version of you who’s reading this at 3am because your kid’s been scratching uncontrollably.

I made Salvida because I needed it. If barrier-first, fragrance-free, clinically tested, steroid-free skincare is what you’re after, I’d love you to try Barrier NPR+. And if you have a question the article didn’t answer, email or DM me. I read every one.

Jacqui

Shop Barrier NPR+ | Shop Bodyguard | Download the Trigger Journal (Coming Soon) | Email me