Common eczema triggers in kids (and how to find yours)

One week your child’s skin is calm; the next it’s red, rough and itchy, and you can’t work out why. Was it the new sweater? The hockey practice? The cold snap? Triggers are the part of eczema parents feel they should be able to control, and it’s frustrating when the pattern won’t show itself. Here’s what usually sets off flares, what the evidence says about food, and a simple way to find your child’s own list.

Why do triggers cause flares?

Triggers don’t cause eczema. Eczema comes from a skin barrier (the outer layer that keeps water in and irritants out) that is leaky, plus an immune system that overreacts to whatever gets through. The Eczema Society of Canada describes it exactly that way: with eczema, the barrier is compromised, so irritants penetrate and set off inflammation.

That’s why the same trigger can bother one child and not another, and why the same child can react to something one month and shrug it off the next. Skin that’s well moisturized and calm lets less through. Skin that’s already dry or flaring reacts to everything. In the Society’s 2021 survey, 72% of caregivers of children with moderate or severe eczema said flares sometimes happen with no identifiable trigger at all, so don’t blame yourself when you can’t find one.

Heat, sweat and cold: the weather triggers

In that Canadian survey, the most commonly reported triggers for children with moderate or severe eczema were exercise or sweating (55%), cold weather (54%), certain fabrics (54%) and warm weather (52%). Weather in both directions, in other words, which will not surprise anyone raising a child in Canada.

Sweat sits on the skin, dries and leaves salt and irritation behind; overheating also makes itch worse. Cold, dry winter air and indoor heating pull water out of already leaky skin. What helps:

• Dress in light cotton layers you can peel off, rather than one warm layer.
• After sports or sweaty play, rinse or wipe the skin with water and reapply moisturizer.
• In winter, moisturize more often, keep baths short and lukewarm, and consider a humidifier if the air indoors is very dry.
• Keep the bedroom on the cool side.

Fabrics, fragrance and detergents: what touches the skin

Wool and scratchy or synthetic fabrics are classic irritants. The Eczema Society of Canada and the NHS both suggest soft, loose cotton next to the skin. Cut out labels or buy tagless clothing, and wash new clothes before the first wear to remove finishing chemicals.

Scented products are the next thing to check. Fragrance turns up in soaps, bubble bath, wipes, lotions and laundry products, and the American Academy of Dermatology recommends mild, fragrance-free cleansers for children with eczema. Choose fragrance-free versions of anything that touches your child’s skin, including your own hand cream if you’re the one applying the moisturizer.

Laundry deserves its own line. The American Academy of Dermatology advises a detergent made for sensitive skin, using only the recommended amount, and rinsing thoroughly. Skip fabric softener and dryer sheets, which coat fabric with fragrance and other residues. If you want to see fragrance-free options, the laundry page on this site lists products whose claims have been reviewed.

Soaps, hot water and long baths

Harsh soap strips the natural fats that hold the barrier together, and hot water does the same. The Eczema Society of Canada calls harsh soaps one of the avoidable triggers, and recommends lukewarm rather than hot water for bathing. Use a mild, fragrance-free cleanser only where it’s needed, keep baths short, pat dry and moisturize within minutes. A whole article on this site covers bathing and moisturizing in more detail.

Infections, stress and other triggers from inside

Two triggers come from within rather than from what touches the skin.

Infections. The NHS lists skin infections, especially with staph bacteria, among the things that set off flares, and general illnesses like colds can do the same. If a flare looks different from usual, with weeping, honey-coloured crusts, pus, spreading redness, pain or clusters of small blisters, or if your child is feverish, see your doctor promptly: an infected flare needs treatment, not just more moisturizer.

Stress. Both the NHS and the Eczema Society of Canada name stress as a trigger, and in the Canadian survey 36% of children with moderate or severe eczema flared with it. For kids, stress can mean a new school year, a move, a sibling’s arrival, or simply being nagged about scratching. You can’t remove stress from a child’s life, but calm routines, enough sleep and not turning the eczema itself into a battleground all help.

Other triggers named by the NHS include house-dust mites, pollen and pets. These are worth noting in your diary, but they’re hard to eliminate, so focus first on the easy wins: fabrics, products and temperature.

What about food?

This is where parents most often go wrong, with the best of intentions. Food can be a trigger for some children, and babies with eczema are at higher risk of developing food allergies. But food allergy doesn’t cause eczema, and cutting foods out rarely fixes it.

A Cochrane review of nine trials found no benefit from egg-and-milk-free diets in children with eczema who weren’t selected for allergy; the only sign of benefit was in infants with a confirmed egg allergy on testing. The NHS puts it bluntly: don’t change your child’s diet, or your own if you’re breastfeeding, unless a doctor tells you to.

There’s also a safety issue. The Canadian Paediatric Society advises that babies at high risk of food allergy, which includes babies with eczema, should be introduced to allergenic foods like cooked egg and peanut early, at about six months and not before four, and keep eating them regularly. Delaying or avoiding those foods can increase the risk of allergy rather than reduce it. So if you suspect a food, write it down and raise it with your doctor, who can decide whether testing makes sense, rather than removing it on your own.

How to keep a trigger diary

You don’t need an app or a spreadsheet, just a notebook or the notes on your phone.

• Each evening, rate the skin in a word: calm, dry, itchy, flaring.
• Note anything new that day: weather, sports, sweating, clothing, a new product, illness, a stressful event, poor sleep.
• If your doctor has asked you to track foods, note them too; otherwise don’t obsess over meals.
• Keep it for two to four weeks, or through one full flare and recovery.
• Look for what repeats before a flare, not what happened once.
• Bring it to your appointment. A pattern you can show is far more useful than a memory.

Change one thing at a time when you test a suspect, and give it a couple of weeks. If you switch the detergent, the soap and the bedding all at once, you’ll never know which one mattered.

Triggers set off flares in skin that’s already vulnerable, which is why moisturizing every day does more than any single avoidance. Look first at heat, sweat, dry air, wool, fragrance and harsh soap, since those are common and easy to change. Treat infections and stress with respect, and treat food with caution and a doctor’s help. And if the flares keep coming despite your best detective work, or the skin isn’t better after two weeks of gentle care, see your doctor or pharmacist; the goal is a child who’s comfortable, not a perfect list.