Skin barrier: what it is and how it is lost
Quick facts
- Definition
- Outer layer of the skin that protects against external agents and prevents water loss.
- Where it is
- In the stratum corneum, the outermost layer of the epidermis.
- Measure
- Transepidermal water loss, which increases when the barrier fails.
- Signs of failure
- Dryness, burning, flaking, sensitivity and redness.
- In facial harmonization
- Skin with a compromised barrier reacts more to procedures and products.
The skin barrier is the outermost layer of the skin, made up mainly of the stratum corneum, part of the epidermis. It works like a wall of cells and lipids: it protects against external agents, such as microorganisms and irritants, and prevents excessive loss of water.
How is it measured?
Function is assessed by transepidermal water loss (TEWL): the more water escapes through the skin, the more compromised the barrier. Measurement requires dedicated equipment, and in the clinic the assessment is usually visual and based on history.
What weakens it?
| Factor | Example |
|---|---|
| Environment | Cold, dry air, sun, pollution |
| Habits | Very hot showers, excessive exfoliation |
| Diseases | Atopic dermatitis, rosacea, acne |
| Procedures | Peels, lasers, microneedling |
| Products | Acids, retinoids and harsh soaps |
An altered barrier leaves the skin more sensitive, more reactive and more prone to inflammation, with less predictable healing.
Why does this matter in facial harmonization?
Before procedures, skin with a compromised barrier may react more, with redness, swelling and discomfort. Afterward, the barrier also suffers from the puncture and from cleansing care. The professional can advise the patient to keep up hydration, sun protection and gentle products, at the discretion of the qualified professional.
Asepsis and the integrity of the barrier go together: intact, clean skin reduces the risk of infection.
Also called: skin barrier, epidermal barrier.
Frequently asked questions
How can you tell whether the skin barrier is compromised?
Skin that burns with products it previously tolerated, that flakes, turns red or is very dry usually points to an altered barrier. Clinical assessment establishes the diagnosis.