What causes atopic dermatitis flares?
Atopic dermatitis, often called eczema, isn’t just dry skin. It’s a broken skin barrier that lets irritants in and moisture out. When that barrier fails, your immune system overreacts, leading to red, itchy, inflamed patches. Flares don’t come out of nowhere-they’re triggered by things you encounter every day.
Cold, dry air is one of the biggest culprits. When humidity drops below 40%, flare risk jumps by 37%. That’s why winter is so tough for people with eczema. Heat is just as bad. Sweat irritates the skin, and 68% of patients report flares when temperatures hit 80°F (27°C) or higher. Even a hot shower can set off a reaction if you don’t follow up with the right moisturizer.
Then there are the invisible offenders: cleansers. Sodium lauryl sulfate, found in many soaps and shampoos, can damage your skin barrier at concentrations as low as 0.5%. Fragrances? They’re in 15% of products that trigger flares. Preservatives like methylisothiazolinone cause contact dermatitis in 5.7% of users. Many people don’t realize their daily body wash or laundry detergent is making things worse.
Genetics play a role too. About 15-50% of people with moderate-to-severe eczema have mutations in the filaggrin gene. This gene helps build the skin’s natural protective layer. When it’s faulty, your skin loses water faster-up to 30 g/m²/h compared to 5-10 g/m²/h in healthy skin. That’s why your skin feels tight and cracked even after moisturizing.
Why emollients are the foundation of treatment
Emollients aren’t just moisturizers. They’re skin repair tools. While steroids calm inflammation, emollients fix the root problem: a leaky skin barrier. They work in three ways: occlusion, hydration, and restoration.
Occlusive agents like petrolatum (Vaseline) form a physical barrier that cuts down water loss by up to 98%. Humectants like glycerin pull water into the skin, especially when used at 40-50% concentration. And ceramides-lipids naturally found in healthy skin-are added back in at 0.5-3% to rebuild the barrier’s structure.
Studies show consistent emollient use reduces transepidermal water loss (TEWL) by 25-50%. That’s not a small improvement. It means your skin stops drying out so fast, itchiness drops, and you’re less likely to scratch-which breaks the cycle that makes eczema worse.
Unlike topical steroids, which carry risks like thinning skin with long-term use, emollients have an excellent safety profile. Only 2.3% of users report side effects, compared to 15-20% for steroids. That’s why the American Academy of Dermatology and the National Eczema Association both list emollients as the #1 first-line treatment.
How to apply emollients correctly
Applying emollient the wrong way makes it useless. It’s not enough to rub it on. You need to seal it in.
The gold standard is the “soak and seal” method. Take a 15-20 minute lukewarm bath-no hot water, no scrubbing. Pat your skin dry, leaving it slightly damp. Within 3 minutes, apply your emollient all over. That’s when your skin is most absorbent. Done right, you lock in 50% more moisture than if you wait longer.
Use enough. Most people use too little. The AAD recommends 250-500 grams per week for adults. That’s about two full tubes of a standard 150g tube every week. For kids, it’s double that. If you’re using less than 100g a week, you’re probably not seeing results.
Apply in downward strokes, following hair growth. Rubbing upward can irritate follicles and trigger itching. Use 2-3 finger units per body section-like one finger-length of cream for each arm, leg, or torso section. Don’t skip the hands, feet, neck, or behind the ears.
Apply twice daily, even when your skin looks fine. Skipping days lets the barrier weaken again. A 6-month study found people who applied emollients twice daily had 36% fewer flares than those who didn’t.
Choosing the right emollient
Not all moisturizers are created equal. Many over-the-counter products contain irritants disguised as “natural” ingredients. Look for these key features:
- Fragrance-free-not “unscented.” Unscented can still contain masking fragrances.
- Preservative-minimized-avoid methylisothiazolinone, parabens, and formaldehyde releasers.
- Ceramide-enriched-look for 0.5-3% ceramide content. Products like CeraVe and Eucerin have this.
- High petrolatum content-Vaseline is cheap, effective, and works for severe flares. Many Reddit users with long-term eczema swear by it.
Popular brands like Cetaphil, Eucerin, and CeraVe make up 65% of the prescription market. In the UK, 78% of patients get emollient prescriptions; in the US, it’s only 42%. That gap matters. Prescription-grade emollients often have higher ceramide and lipid concentrations than drugstore brands.
Cost is a real barrier. Ceramide creams can run $18-$25 per tube. Petrolatum (Vaseline) costs under $9. If cost is an issue, start with petrolatum for flares and switch to ceramide creams for maintenance. A 2020 study showed patients using over 100g per week had 43% fewer flares than those using less than 50g.
When emollients aren’t enough
Emollients work best for mild cases and prevention. But if you’re in a severe flare-cracked, bleeding, oozing skin-emollients alone won’t cut it. They reduce flares by 36% over six months, but they clear up active inflammation in only 30-40% of mild cases.
For moderate-to-severe flares, you’ll likely need a short course of topical steroids or calcineurin inhibitors like tacrolimus. These are safe when used correctly on sensitive areas like the face or eyelids. For chronic, stubborn cases, biologics like dupilumab can reduce flares by 70-80%. But even then, emollients are still used alongside them. As one dermatologist puts it: “Without barrier repair, nothing else works.”
Some patients develop “emollient resistance”-not because the product stopped working, but because Staphylococcus aureus bacteria overgrow on damaged skin. This needs targeted treatment like bleach baths or antibiotics.
Why people stop using emollients-and how to stick with it
Here’s the hard truth: 30-65% of people quit using emollients within six months. Why? Greasiness. Sticky residue. Time. It’s not laziness-it’s the product design.
Urea-based creams feel sticky. Some ceramide lotions are too thick. And applying twice daily, every day, takes effort. One survey found 67% of patients say time constraints are the main reason they skip applications.
Solutions? Try lighter formulations for daytime (lotions or gels) and heavier ointments at night. Keep tubes in the bathroom, bedroom, car, and office. Make it part of your routine-right after brushing your teeth or before bed. Use a pump bottle to reduce mess.
And don’t feel guilty if you need help. Ask your dermatologist for samples. Many clinics offer free starter kits. The National Eczema Society’s application guide scores 4.7/5 for clarity-use it. Most product labels don’t tell you how much to use or when. You need to know.
What’s new in emollient therapy
The field is evolving. In May 2023, the FDA approved the first emollient with sustained-release ceramides. It reduces water loss by 63% over 12 hours-nearly double older formulas. That means fewer applications needed.
Researchers are also testing microbiome-targeted emollients. These don’t just moisturize-they feed good skin bacteria and crowd out harmful ones like Staphylococcus aureus. Phase 2 trials are underway.
Smart dispensers that track how much you use and remind you to apply are being tested in hospitals. If you’ve ever forgotten to moisturize, this could be a game-changer.
The guidelines have changed too. The International Eczema Council now recommends at least 200g per week for adults-up from 100g. Why? Because newer studies show dose matters. More is better, as long as it’s applied correctly.
Bottom line: Consistency beats perfection
You don’t need the most expensive product. You don’t need to be perfect. You just need to be consistent.
Fix your barrier. Avoid the triggers. Use enough emollient. Apply it right after bathing. Stick with it-even when your skin looks fine.
Atopic dermatitis isn’t cured by one miracle cream. It’s managed by daily care. The science is clear. The tools are available. The hardest part isn’t knowing what to do-it’s doing it, every day. But if you do, your skin will thank you.
