Eczema and Skin Bacteria, Why Microbial Balance Matters

Healthy skin is home to a diverse community of microorganisms that protect against infection and help regulate immune responses. In eczema, this ecosystem becomes disrupted, contributing to inflammation and flare severity.

What Happens to the Skin Microbiome in Eczema

People with eczema often have reduced microbial diversity on their skin, with an overgrowth of Staphylococcus aureus. This shift is not simply an infection, it reflects a loss of balance in the skin ecosystem¹.

Staphylococcus aureus produces toxins known as superantigens that activate immune cells broadly, increasing cytokine release and inflammation². This immune activation further damages the skin barrier, making it easier for bacteria to persist.

Barrier Damage Drives Dysbiosis

A healthy skin barrier helps regulate which microbes can live on the surface. When the barrier is compromised:

• Moisture loss increases
• Skin pH changes
• Antimicrobial peptides decrease

These changes favor the growth of inflammatory bacteria while reducing beneficial species. This explains why antimicrobial treatments alone rarely lead to lasting improvement.

Why Repeated Antibiotics Often Fail

Antibiotics can temporarily reduce bacterial load, but they do not restore barrier integrity or microbial diversity. In some cases, repeated antibiotic use worsens long-term dysbiosis, increasing the likelihood of rebound flares³.

The Big Takeaway

Eczema-related microbial imbalance is a consequence of barrier dysfunction and immune activation, not simply an infection. Supporting skin resilience and microbial balance is more effective than repeated eradication strategies.

References

1. Kong HH, et al. Temporal shifts in the skin microbiome associated with disease flares in atopic dermatitis. Genome Res. 2012.
2. Bunikowski R, et al. Staphylococcus aureus superantigens and cytokine induction in atopic dermatitis. J Allergy Clin Immunol. 2000.
3. SanMiguel AJ, et al. Antimicrobial use and resistance in atopic dermatitis. Curr Dermatol Rep. 2017.