What is Staphylococcus aureus (Staph)?

If you have eczema, you may have heard of Staphylococcus aureus, often called “Staph.” While it sounds technical, the name comes from Greek staphulē (bunch of grapes) and kokkos (berry), describing its appearance when viewed under a microscope.

What exactly is Staph?

Staphylococcus aureus is a naturally occurring bacterium found on the skin. Many people carry it without any issues. However, for those with eczema, it can play a key role in triggering flare-ups.

• Around 20–30% of people carry it regularly
• It usually causes no problems on healthy skin
• Issues arise when the skin barrier is weakened
  

Why does Staph matter for eczema?

Eczema weakens the skin’s protective barrier and this makes it easier for Staph to grow and spread. When Staph levels increase on the skin, it can:

• Irritate and damage the skin barrier
• Trigger inflammation and redness
• Increase itching
• Slow down skin recovery

This creates a cycle that many people with eczema experience:

Weakened skin → more Staph → more irritation → further damage

Why is Staph so common in eczema?

Research shows that people with eczema tend to have much higher levels of Staph on their skin, especially during flare-ups.

One reason is that eczema-prone skin lacks the same level of natural defences (including antimicrobial activity) as found in healthy skin. As a result, Staph is able to grow more easily, stay on the skin longer, and contribute to ongoing inflammation.

You can think of eczema-prone skin as having a “leaky” barrier.

This allows:

• Moisture to escape
• Irritants to enter
• Bacteria like Staph to thrive

Managing eczema often involves addressing all three of these factors, not just the visible symptoms like redness or roughness.

What this means for eczema care

Understanding the role of Staphylococcus aureus helps explain why eczema can be persistent and why flare-ups can keep returning.

It also highlights an important idea, that eczema isn’t just about dry skin, but that it is linked to the balance of bacteria on the skin.

References

• National Eczema Association: https://nationaleczema.org
• American Academy of Dermatology: https://www.aad.org
• Kong HH et al. “Temporal shifts in the skin microbiome associated with disease flares and treatment in children with atopic dermatitis.” Genome Research
• Nakatsuji T et al. “Antimicrobials from human skin commensal bacteria protect against Staphylococcus aureus.” Science Translational Medicine