The Skin Microbiome — Why It Matters for Kids and What Chlorine Does to It
Key Takeaways
Kids’ skin has a microbiome — a living community of beneficial bacteria, fungi, and microbes that supports skin health, moisture, and resilience.
The microbiome helps regulate inflammation, protect the skin barrier, and reduce irritation, dryness, and eczema flare-ups.
Children’s microbiomes are more fragile than adults’, making them more reactive to environmental exposures like chlorine, harsh soaps, fragrances, hot water, and overwashing.
Chlorine is a major disruptor of the skin microbiome. It can dry the skin, damage the protective barrier, and reduce beneficial bacteria that keep inflammation in check.
Common signs of microbiome disruption after swimming include itchy skin, dryness, chalky texture, redness, and eczema patches appearing hours later.
Emerging research shows chlorine can bind to skin proteins, potentially altering microbial balance even after showering.
Neutralizing chlorine immediately after swimming helps protect both the skin barrier and the microbiome, reducing irritation and post-swim flare-ups in sensitive kids.
Supporting the microbiome is simple: reduce harsh exposures, avoid antibacterial soaps, choose gentle products, and remove chlorine quickly after pool time.
If you have a child with sensitive skin, eczema, or a magical ability to break out in a rash from literally nothing, chances are you’ve already tried all the dermatologist-recommended, fragrance-free lotions, creams, and soaps.
I know because I was that kid — and my parents tried all those things.
When I had my first baby, I tried all those things too, and ended up with a bathroom full of products that never really worked.
But here’s the thing we didn’t know: kids’ skin isn’t just a barrier. It’s a living ecosystem.
What is the skin microbiome and what does it do?
Over the last decade, researchers have discovered that the skin is home to millions of beneficial bacteria, fungi, and microbes that act like a microscopic neighborhood watch. This bustling community is called the skin microbiome, and in kids — whose skin is thinner and still developing — it plays an even bigger role in hydration, resilience, and overall skin health.
According to a comprehensive review in Nature Reviews Microbiology, the skin microbiome helps maintain a strong barrier, regulate inflammation, and protect against irritation and infection.
Once I learned this, it completely changed how I approached post-swim care, bath time, and how I chose products for my kids’ skin.
Why kids’ skin needs a healthy microbial balance
Think of your child’s microbiome as their personal team of tiny bodyguards. When that team is strong and balanced, their skin is better able to:
Fight off irritation and rashes
Hold onto moisture
Maintain a strong barrier
Calm inflammation naturally
Keep eczema from spiraling into “why is this happening again?” territory
Pediatric dermatology research shows that kids with eczema often have less microbial diversity — which basically means fewer “good guys” on the team. This is the same concept often discussed in gut microbiome health — as a general rule, we always want more “good guys” than “bad guys”.
And because children’s microbiomes are still developing, they’re way easier to disrupt than ours.
How the skin microbiome gets disrupted
Unfortunately, it doesn’t take much to disrupt a child’s skin microbiome. Everyday things can cause an imbalance, such as:
Overwashing
As much as I love a clean-kid, overwashing strips: oils, good bacteria, and moisture, which can cause way more irritation than leaving a little dirt on them.
Harsh soaps or antibacterial cleansers
Hand Sanitizer
Most hand sanitizers use alcohol and antimicrobial agents that obliterate the skin microbiome on contact. This is fine in a pinch at a public restrooms, but not great for daily use.
We use BrioTech
Antibiotics
Antibiotics kill microbes — which is helpful for infections but not great for a balanced microbiome. For eczema-prone kids, repeated or long-term antibiotics can create shifts that make flare-ups more common.
Laundry Detergents
Fragranced detergents, fabric softeners, and dryer sheets leave behind chemicals that rub directly against skin. Kids with eczema often react to:
synthetic fragrance
surfactants
preservatives
brighteners
All of which can affect the skin barrier and microbiome.
We use Truly Free or Attitude
Sunscreens With Harsh Filters
Chemical sunscreens (especially oxybenzone, octinoxate, avobenzone) can irritate the skin and alter microbial communities. Mineral sunscreens are generally better tolerated for microbiome health — especially zinc-only formulas.
We use Babo Botanicals and Sky & Sol
Fragrances
Fragrance is one of the most common skin irritants and microbiome disruptors. Even essential oils — although “natural” — can overwhelm sensitive skin if highly concentrated.
Hot water
Yes, even water can be too aggressive. Hot water weakens the lipid barrier, increases transepidermal water loss, and dries the skin microbiome out. Kids really do best with lukewarm baths/showers.
Chlorine
Strips natural oils, binds to skin proteins, disturbs good bacteria, and leaves behind irritants (chloramines). Kids with eczema or sensitive skin feel this disruption FAST
Why kids’ microbiomes are more fragile than adults
Kids’ skin is still developing, which means their barrier is thinner, more delicate, and more permeable than adult skin. And while the skin doesn’t absorb everything we put on it, it can absorb certain ingredients—especially small molecules or products designed to penetrate. It also reacts quickly to environmental exposures (like chlorine) because kids have a higher surface-area-to-body-weight ratio.
Put simply: their skin is more sensitive, more reactive, and less equipped to handle harsh exposures… which brings us to the microbiome.
Because when the skin barrier is still maturing, the microbiome — that little community of beneficial bacteria living on the skin — becomes even more important. And when that delicate balance gets disrupted, kids often show the effects fast:
Dry, tight skin
Redness
Sudden itchiness that seems to come out of nowhere
“Chalky” or squeaky-feeling skin
Eczema patches popping up after swimming or bathing
It’s not just “sensitive skin.” Their barrier and microbiome are raising the white flags at the same time.
Why chlorine matters more than we thought
If you’re still with me, the problem with chlorine is that it isn’t just drying the skin — it can actually disrupt the microbial balance.
The American Academy of Dermatology explains that disinfectants like chlorine can worsen eczema and irritate sensitive skin by damaging the natural barrier.
Chlorine worsens things like eczema because it reduces beneficial bacteria on the skin. It takes out the “good guys”. Which means the body has less ability to keep inflammation under control.
Suddenly it makes sense why so many parents notice:
Extra itching after swimming
Dry patches showing up hours later
Eczema flare-ups the day after pool time
Skin still irritated even after showering
Kids’ skin is still developing, which means their barrier is thinner, more delicate, and more permeable than adult skin.
What research says about kids, chlorine, and the microbiome
1. Kids’ microbiomes are more fragile
Children have different microbial communities than adults, and their “good bacteria” shift more easily.
NIH Human Microbiome Project from the National Institutes of Health
→ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3377744/
2. Chemical exposures — especially chlorine — can shift microbial balance
Research shows chlorine can bind to skin proteins and alter microbiome composition even after washing.
→ https://pubmed.ncbi.nlm.nih.gov/12584712/
3. Healthy microbiomes are linked to fewer eczema flares
Kids with more diverse microbiomes tend to have milder eczema symptoms.
→ https://pubmed.ncbi.nlm.nih.gov/28389261/
4. Neutralizing chlorine after swimming helps the microbiome recover
Parents commonly report fewer flare-ups, less dryness, and calmer skin when chlorine is neutralized right away — not hours later in the bath.
This is a big reason chlorine-neutralizing sprays are becoming so popular for sensitive or eczema-prone kids: they protect both the skin barrier and the microbiome.
The Bottom Line
A healthy microbiome = healthier skin.
And since chlorine can disrupt both the moisture barrier and the microbial ecosystem, neutralizing it after swimming is one of the simplest, smartest things you can do to support your child’s natural defenses — especially if they’re sensitive or eczema-prone.
What I would have given to know this 30 years ago.