Many of the eczema creams available in the market are sold by emphasizing familiar concepts: Our eczema cream has ceramides, contains colloidal oatmeal, works on “skin barrier repair,” or is “dermatologist recommended.” But one critical variable is rarely discussed: the pH of the product. Let’s discuss in detail.
What is the pH of the product?
In a healthy human skin, the skin surface pH typically remains mildly acidic, around 4.7–4.9. It happens when external factors are under control. The surface acidity is not a random thing or serves any cosmetic purpose. It is required to:
- Regulate the itch signalling
- Optimize ceramide generation
- Stabilize the skin microbiome
- Suppress serine proteases
- Organize proper lamellar membrane
In atopic dermatitis (eczema), the skin surface pH rises. It often reaches 5.2 to 6.0 or higher. That means applying a moisturizer that has a pH of 5.5, 6.0, or 6.7 may further push the skin into a biochemical range that destabilizes the skin barrier and immune function.
To understand how common this issue is, we measured the pH of several widely used eczema creams.
What We Tested
We tested the following products using calibrated pH instrumentation under standardized conditions.
Products with a pH of ≥ 6
Products With a pH of 5.0–5.9
- Cetaphil – pH 5.8
- Eucerin Baby – pH 5.5
- Eucerin Eczema Relief – pH 5.4
- CeraVe Moisturizing Cream – pH 5.6
- CeraVe Eczema Relief Creamy Oil – pH 5.5
Products With a pH of < 5 and Active Buffer Capacity
- Soteri Baby Eczema Cream – pH 4.9
- Soteri Long-Term Eczema Relief Cream – pH 4.7
- Soteri Active Flare-Up Relief Cream– pH 4.8
We found Striking Results
The most popular eczema cream had a pH above the physiological pH range of healthy skin.
What is the Best pH for Eczema-Prone Skin?
When healthy skin is allowed to heal and recover without frequent washing or harsh surfactant exposure, it naturally stabilizes at approximately pH 4.7–4.9.
In atopic dermatitis, the skin is different:
- The activity of Proteases increases as the pH rises
- Recovery of the skin barrier is delayed at higher pH
- Skin with no lesions is frequently mildly elevated
- Skin that has lesions often measures between 5.2 and 6.1
This means that the skin prone to eczema is already and inherently operating in a compromised biochemical environment.
The application of a product that has a pH of 5.5, 6.0, or 6.7 does not contribute to restoring the physiological acidity of the skin. In many cases, it may either maintain or even worsen the alkalinity.
Why pH 5.0 and Above Is Not Optimal for Eczema
A difference of 0.5 or 1.0 pH units may sound small, but it is not. Each shift in the unit represents a tenfold change in hydrogen ion concentration. Hence, pH is logarithmic. Even slight changes or shifts produce measurable biochemical effects on the skin.
1. Effects on Lipid-Processing Enzymes
Two enzymes are essential for ceramide production in the stratum corneum:
- β-glucocerebrosidase
- Acidic sphingomyelinase
Both these enzymes operate optimally in mildly acidic conditions.
When the skin pH is ≥ 5.5:
- The activity of ceramide enzymes declines
- Ceramide conversion becomes incomplete
- Lamellar membranes become disorganized
- Recovery of the skin barrier slows down
Eczema-prone skin already exhibits ceramide deficiencies, and a moisturiser that sits above physiological pH does not support enzymatic correction in such a situation.
2. Effects on Serine Proteases (Kallikreins)
Kallikrein-5 (KLK5) and kallikrein-7 (KLK7), serine proteases, are produced by keratinocytes in the epidermis. They function to regulate the desquamation process in the skin. Under acidic conditions, their activity is also affected.
As the pH of skin rises:
- KLK activity increases exponentially
- Corneodesmosomes degrade prematurely
- Stratum corneum cohesion weakens
- Micro fissures develop
More importantly, KLK5 activates protease-activated receptor-2 (PAR2).
PAR2 activation triggers:
- Thymic stromal lymphopoietin (TSLP) release
- Pro-inflammatory cytokines
- Direct stimulation of sensory nerves
Elevated skin pH, therefore, amplifies PAR2-activated itch signalling, even if no visible inflammation is present.
3. Effects on the Microbiome
Skin acidity also shapes the skin's microbial ecology. It supports beneficial microbiomes and prevents the growth of harmful bacteria.
At pH 4.7–4.9:
- Commensal organisms flourish
- Colonization resistance is maintained
- Organic acid production reinforces acidity
At pH 5.5 and above:
- Staphylococcus aureus persistence increases
- Virulence factors become more active
- Dysbiosis becomes more likely
Numerous studies show that elevated skin pH correlates with greater S. aureus colonization in atopic dermatitis.
If eczema-prone skin is already vulnerable to dysbiosis, applying a cream at pH 6.2 or 6.7 may create more favourable conditions for pathogenic organisms.
Why pH ≥ 6 Is Particularly Concerning for Atopic Skin
The products measured at or above pH 6 included:
- Skinfix – 6.2
- Aveeno Baby – 6.2
- First Aid Beauty – 6.7
At pH 6.7, the product is over 100 times less acidic than the physiological skin pH 4.7.
In eczema-prone skin, where:
- Protease activity is already elevated
- Skin barrier recovery is impaired
- Microbial imbalance is common
A product in the 6+ range may further:
- Sustain kallikrein activation
- Delay ceramide regeneration
- Increase TEWL (Trans epidermal Water Loss)
- Support dysbiosis shifts
Even if the formulation applied contains beneficial ingredients such as colloidal oatmeal or ceramides, the biochemical environment still is not suitable to support optimal function.
What about pH 5.4–5.8?
Many products cluster in the 5.4–5.8 range:
- Eucerin Eczema Relief – 5.4
- Eucerin Baby – 5.5
- CeraVe – 5.5–5.6
- Cetaphil – 5.8
These are closer to the physiological pH of skin but still fall above the natural equilibrium range of 4.7–4.9.
At pH 5.5:
- β-glucocerebrosidase activity is reduced relative to 4.8
- KLK activity is higher than at 4.7
- Re-acidification may be incomplete
A non-eczema skin may tolerate this well, but for atopic skin already shifted pH upward, maintaining a 5.6–5.8 surface may not be sufficient to restore enzymatic balance.
The Importance of Active Buffer Capacity
Active buffer capacity refers to a formulation's ability to resist pH shifts and maintain sustained acidity on the skin surface. The concept here also relates to the buffer capacity of the formulations we tested.
There is a difference between:
- A product that measures pH 4.8 in the bottle
- A product that maintains skin pH at 4.8 after application
Products measured below pH 5 in this testing included:
- Soteri Long-Term Relief Cream – 4.7
- Soteri Active Flare-Up Relief Cream– 4.8
- Soteri Baby Eczema Relief Cream – 4.9
These values fall within the physiological equilibrium range for healthy skin.
When applied to elevated atopic skin, the goal is not a temporary acidic shift but stabilization within this optimal range.
The Protease–pH–Itch Axis in Eczema
Atopic dermatitis is characterized by a self-amplifying loop:
Elevated pH → Increased kallikrein activity → PAR2 activation → Cytokine release → Itch → Scratching → Barrier damage → Further pH elevation
Moisturizers are meant to break this loop, but if the moisturizer’s pH sits above 5.5 or 6.0, it may fail to suppress the upstream biochemical trigger.
Lowering the pH toward 4.7–4.9 helps to:
- Suppress KLK activity
- Reduce PAR2 signaling
- Support lamellar repair
- Stabilize microbiome composition
Addressing pH on the skin is therefore not a cosmetic requirement but a mechanistic relevance.
Why This Is Especially Important for Babies
Infant skin:
- Has a thinner stratum corneum
- Has an immature barrier function
- Has reduced buffering capacity
- Is more susceptible to TEWL
Baby eczema products with a pH of 6.2 may not support acid mantle restoration.
Early-life skin barrier instability is associated with a higher risk of progression of atopic disease. It is very important to maintain the physiological acidity, particularly in infancy.
Summary of What We Found
What we found was that most of the popular eczema creams we tested fall into one of two categories:
- pH 5.4–5.8 — closer to neutral than physiological acidity
- pH ≥ 6.0 — clearly outside the optimal range for atopic skin
Very few formulations were found to sit within the natural equilibrium range of 4.7–4.9.
For eczema-prone skin, where pH is already elevated, this difference is clinically very meaningful.
Soteri Skin: Built Around pH Science for Eczema
In conclusion, our trial reveals that Soteri Skin eczema cream gives relevant clinical and biochemical benefits to an eczema-prone skin. The formulations they offer effectively address the key pathological features of atopic dermatitis. Furthermore, it restores the integrity of the skin barrier and supports the growth of microbiomes to support eczema relief. Soteri Skin Eczema formulations also optimize the pH of skin, improving its protective function and maintaining a healthier microenvironment. Collectively, all these effects provide long-term symptomatic relief from eczema and restore skin integrity.
FAQs
How often should I apply Soteri Skin for atopic dermatitis?
For best results, apply Soteri Skin Eczema relief cream 1–2 times daily. With regular use, the skin barrier strengthens, reducing flare-up intensity. And relieving symptoms.
Can I use Soteri Skin formulation on all affected areas?
Yes. Soteri Skin Eczema Formulations are totally safe for use on any eczema-prone area. However, precaution is advised while using near the eyes and sensitive organs.
What is the acid mantle, and how does Soteri Skin support it?
The acid mantle is a thin, acidic layer on the surface of your skin. Its main function is to act as a protective layer against pathogens and enzyme overactivity. Soteri Skin eczema cream, by enhancing the lipid balance and correcting skin pH in atopic dermatitis, helps to maintain this layer, consequently leading to healthier skin.
How does a properly pH-balanced cream help manage eczema?
Using a cream that helps correct the skin's pH helps maintain the acid mantle. Additionally, the optimal pH of eczema cream protects the skin microbiome and reduces kallikrein and PAR2 activity associated with inflammation and itch signalling on skin. Soteri Skin formulations support all these mechanisms and give lasting symptomatic relief.
Final Takeaway: Not All Moisturizers Are Biochemically Equal
Eczema management often focuses on:
- Steroids
- Biologics
- Anti-inflammatory ingredients
- Ceramide content
But what matters most is the foundational barrier to biochemistry. Maintaining skin surface pH within the physiological acidic range:
- Supports enzyme activity
- Suppresses proteases
- Stabilizes microbiome ecology
- Reduces itch amplification
Products with pH ≥ 6 may be particularly suboptimal for atopic skin, as they sit within the range associated with protease activation and microbial imbalance.
For patients with eczema, especially those with moderate-to-severe atopic dermatitis, pH should be considered a core parameter rather than an afterthought or extra factor.
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