Introduction

If you deal with persistent itch, recurring eczema flare-ups, or skin that feels inflamed no matter what you try, a common skin bacterium called Staphylococcus aureus (S. aureus) may be playing a bigger role than you realize.

S. aureus naturally lives on the skin of many healthy people. But when the skin barrier is damaged or the microbiome becomes unbalanced, this bacterium can overgrow, thereby triggering inflammation, worsening itch, and prolonging flare-ups.

Today, scientists are learning that managing S. aureus is not achieved by eliminating all bacteria. Instead, it’s about restoring balance. That’s where phage lysates, a new microbiome-targeted technology, come into play.

What Is S. aureus? [1]

S. aureus is a type of bacteria commonly found on both the skin and inside the nose. For many people, it causes no issues at all. However, for those who suffer from:

• Eczema or atopic dermatitis
• Chronic itch
• Sensitive or reactive skin
• A weakened skin barrier
  

S. aureus can multiply rapidly and contribute to skin inflammation.

Studies have shown that over 90% of eczema lesions are colonized by S. aureus, compared to much lower levels being found on healthy skin.

In a recent study, researchers sampled the skin of pediatric eczema patients before a flare, during the flare, and after the flare. They analyzed the skin microbiome using advanced gene sequencing techniques. What they observed was the presence of increased levels of S. aureus in samples taken during flares than in samples taken before and after the flares, or from healthy controls. This demonstrated the association of S. aureus with eczema flares and how S. aureus can exacerbate eczema symptoms like itch.

Why Does S. aureus Cause Flare-Ups?

1. It Thrives on a Damaged Skin Barrier

Healthy skin serves as the body’s protective shield. When the skin barrier is compromised:

• Moisture escapes
• Skin pH rises
• Natural defenses weaken

This creates an ideal environment for S. aureus to grow.

2. It Produces Inflammatory Toxins

S. aureus releases toxins that:

• Irritate skin cells
• Activate immune responses
• Increase redness, swelling, and sensitivity

These toxins not only trigger symptoms but also prolong inflammation, thereby making flare-ups even harder to calm down.

3. It Disrupts the Skin Microbiome

Healthy skin is home to many beneficial microbes. When S. aureus dominates, microbial diversity drops, and inflammation increases.

S. Aureus infections typically start as red bumps or red streaks that can evolve into sores, pus-filled blisters or yellow-colored crusts. For those with eczema, these infections lead to severe itch which in turn leads to scratching, bleeding, and a higher risk of not only spreading the infection through one’s fingernails but into the bloodstream as well.

Why Does S. aureus Cause So Much Itch?

Itch isn’t just a by-product of “dry skin.” It’s driven by a series of complex communications between the body’s immune and nervous systems.

A new finding made by University of Michigan Medical School researchers reported that a toxin produced by S. aureus causes immune cells in the skin to react in a way that produces eczema-like rashes. Specifically, this molecule called delta toxin, caused immune-related mast cells in the skin to release tiny granules that cause inflammation. But this didn't occur when skin was exposed to staph strains that lacked the gene for delta toxin.

How S. aureus Triggers Itch

• Direct nerve stimulation: Certain S. aureus toxins can activate itch-sensing nerves in the skin
• Inflammatory signaling: The bacteria stimulate immune cells to release itch-promoting molecules like IL-31
• The itch-scratch cycle: Scratching damages the skin, allowing more bacteria to enter, which leads to more itch

This is why itch linked to S. aureus oftentimes doesn’t respond well to antihistamines.

Traditional Ways to Treat S. aureus [2]

Common treatments include:

• Topical steroids to reduce inflammation
• Antibiotic creams or oral antibiotics to reduce bacteria
• Antiseptic washes

While these can help in the short term, they may:

• Disrupt beneficial skin bacteria
• Lead to recurring flare-ups
• Contribute to antibiotic resistance

This has led researchers to explore more targeted solutions.

The Skin Microbiome: Why Balance Matters

Your skin microbiome is a community of microbes that:

• Protect against harmful bacteria
• Support the skin barrier
• Help regulate inflammation

Healthy skin isn’t sterile, it’s balanced! Supporting beneficial microbes while controlling harmful ones is the key to long-term skin health.

What Are Phages? [3]

Phages, short for bacteriophages, are naturally occurring viruses that infect ONLY bacteria. Each phage targets specific bacterial species and does not affect human cells.

They exist naturally in the environment and even in our skin.

What Are Phage Lysates?

Phage lysates are bioactive ingredients made from phages and their bacterial targets. Unlike live phages, lysates do not replicate, making them well-suited for skincare formulations. Phage lysates contain:

• Proteins that weaken harmful bacteria
• Components that reduce bacterial toxin activity
• Signals that help calm inflammation

How Phage Lysates Help Control S. aureus [4]

Phage lysates work differently than antibiotics:

Targeted Action

They are designed to specifically impact S. aureus without wiping out beneficial microbes.

Reduced Inflammation

By limiting bacterial toxins, phage lysates help reduce the immune responses that drive redness and itch.

Support for the Skin Barrier

Less inflammation allows the skin barrier to repair itself, making it harder for S. aureus to return.

Lower Resistance Risk

Because phage-based approaches are highly specific, they carry a lower risk of resistance than antibiotics.

Phage Lysates and Itch Relief

By reducing S. aureus activity and calming inflammation, phage lysates may:

• Decrease itch-triggering signals
• Reduce nerve sensitivity
• Help break the itch-scratch cycle

Over time, this can lead to fewer flare-ups and more comfortable skin.

How to Help Prevent S. aureus-Related Flare-Ups

Moisturize regularly to support the skin barrier

• Use gentle, non-stripping cleansers
• Avoid overusing antibacterial products
• Focus on microbiome-friendly skincare
• Manage stress to avoid worsening inflammation
• Add salt soaks to your routine to soothe itch
• Consider using bleach baths and/or hypochlorous acid spays
• Consistency matters more than aggressive treatments.

Common Myths About S. aureus

Myth: All bacteria on the skin are harmful
Fact: Many bacteria are essential for healthy skin

Myth: Stronger antibiotics are always better
Fact: Targeted approaches may better support long-term balance

Myth: Itch is just dryness
Fact: Itch is often driven by the immune system and nerve signaling

Frequently Asked Questions

What causes S. aureus to overgrow on skin?
A damaged skin barrier coupled with reduced microbial diversity.

Is S. aureus contagious?
While it can spread through contact, overgrowth (the problem) depends on skin health.

Why don’t antihistamines stop eczema itch?
Many itch pathways are not histamine-based.

Are phage lysates safe for sensitive skin?
Yes, when properly formulated for topical use.

Do phage lysates kill good bacteria?
No, they are designed to be highly targeted.

Conclusion

S. aureus plays a prominent role in chronic itch and skin flare-ups by disrupting: the skin barrier, microbiome, and immune system. While traditional treatments focus on symptom control, newer approaches like phage lysates aim to restore balance by helping skin calm down, heal, and stay resilient. If you’re struggling with recurring flare-ups, addressing S. aureus at the microbiome level may be an important step toward lasting relief.

Call to Action

Have you experienced eczema-triggered chronic itch or recurring skin flare-ups? If so, Codex has just what your sensitive, compromised skin barrier needs to effectively combat and manage eczema-related symptoms. Our newly launched, state-of-the-art BIA BIOME RESET GEL, ideal for itchy, eczema-prone skin, is a lightweight gel that delivers microbiome balancing actives (phage lysates) and niacinamide to restore the skin barrier. It has been clinically proven to shift (rebalance) the skin microbiome and reduce levels of S. aureus present on the skin.

For those looking for immediate soothing relief from itch, there is the BIA SENSITIVE SKIN SOOTHING SALT WRAP, a calming and soothing salt wrap enriched with oat seed oil, gotu kola, and chickweed. A must-have for those needing fast, effective relief from eczema-induced itch.

Lastly, for those individuals with sensitive, eczema-prone skin that want to make sure that whatever buggies residing on their fingertips do not get transferred onto their skin when using a product that requires a finger for removal and application, there is the LUNAESCENT TOUCH-FREE SKINCARE APPLICATOR, an applicator that revolutionizes skin treatment by ensuring hygienic, touch-free application, minimizing contamination, and enhancing treatment absorption by protecting active ingredients. It’s ideal for use with microbiome gels and serums.

With one or more of the above-referenced eczema management tools in your skincare toolbox, you’ll be well on your way to effectively managing the maddening itch sensation associated with eczema. How can we be so sure? Because we have the clinical data to prove it!

References

• https://www.cdc.gov/staphylococcus-aureus/about/index.html
• https://www.ncbi.nlm.nih.gov/books/NBK441868/
• https://www.who.int/europe/news-room/fact-sheets/item/bacteriophages-and-their-use-in-combating-antimicrobial-resistance
• https://pmc.ncbi.nlm.nih.gov/articles/PMC5784253/