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What Causes Skin Redness? (Hint: Skin Acid Mantle)

Updated: 7 days ago

The skin should have a natural, non-irritated tone to it. When the skin's acid mantle gets damaged, the skin will get red and irritated.

What is the acid mantle on the skin?

The skin acid mantle is a thin, protective layer on the surface of the skin that acts as a first barrier to the outside world. It is your skin's first line of defense. This acid mantle consists of a slightly acidic film, typically with a pH of 4.7 - 5.75 and it helps protect the body against harmful microorganisms and environmental stressors. The skin acid mantle also plays a role in keeping the skin moisturized and healthy.

ℹ️ Notice that you have a microbes, an acid layer, and a fat layer BEFORE you even get to the start of you skin cells!! There is a lot that sits on top of your skin cells!

ℹ️ If you have a damaged acid layer, it is likely that your lipid layer is also damaged, which is why your skin cells are red and irritated from contact with the outside environment.

What makes up the Acid Mantle?

Amino Acids

Lactic Acids (Notice the word acid in both of these)

The acid mantle is made up of free amino acids and Lactic Acids (Alpha-Hydroxy Acids - AHAs). Sweat from working out is how your body delivers these free amino acids and Lactic acids to the skin's acid layer. This is often why marathoners and sauna-lovers often have fantastic skin. Source

What Makes up the Lipid barrier?

The skin's acid mantle sits on top of a lipid barrier. That lipid barrier is primarily made up of cholesterol, ceramides (a waxy fat), and fatty acids.

Does a damaged acid mantle cause redness?

YES. When the skin acid mantle has been damaged the skin will get red. A damaged acid mantle often means that the pH of the skin is too high (read: too alkaline, at a pH over 5.75).

A damaged acid mantle can be repaired by bringing the skin acidity back down to its ideal pH of 4.7-5.75. As skin pH reaches its ideal acidity, the mantle will heal and redness will go away.

Reader, if you have red skin (including rosacea) you should look into using an acidic skincare product if you have not already.

What are the signs of a disturbed skin acid mantle?
  • Irritation and Redness 🔴: The skin becomes more prone to irritation and redness due to increased sensitivity. This includes hyperpigmentation and rosacea.

  • Acne🦠: Disruption of the acid mantle can create an environment conducive to the growth of acne-causing bacteria, potentially leading to breakouts.

  • Dryness 🌵: An imbalanced acid mantle can lead to a lack of moisture retention, resulting in dry and flaky skin.

  • Increased Sensitivity: The skin may become more sensitive to external factors such as temperature changes, wind, or certain skincare products.

  • Inflammation: Inflammatory conditions like eczema or rosacea may worsen when the acid mantle is disturbed.

  • Pruritus (Itching) : Disrupted pH levels can contribute to itching and discomfort.

  • Dull, Uneven, or Blotchy Skin Color: A compromised acid mantle may result in a dull complexion and uneven skin texture.

What Causes a Disturbed Acid Mantle on the Skin?
  • Harsh Cleansers 🧼: Using cleansers that are too alkaline or contain harsh surfactants can disrupt the skin's natural pH balance, stripping away protective oils and weakening the acid mantle. ℹ️ THIS INCLUDES SOAP. USING TOO MUCH SOAP STRIPS AWAY YOUR SKINS NATURAL OILS AND DAMAGES YOUR ACID MANTLE. If you are interested in reducing your redness look into 'soap-free cleansers'

  • Over-Exfoliation 🧽: Excessive physical exfoliation or chemical exfoliation will damage the skin barrier and disrupt the acid mantle making you red and irritated.

  • HARD WATER 💦: Yes, hard water is alkaline from all the added minerals and will hurt the skin acid mantle. You can combat this with acidic cleansers. Oil cleansing also helps here.

  • Environmental Factors : Exposure to environmental stressors such as pollution, UV radiation, harsh weather conditions, and hard water can disrupt the acid mantle and compromise the skin barrier.

  • Skin Care Products: Besides soap (see above), alcohol and fragrance using alcohol (perfumes) will strip your skin's acid mantle and will lead to skin damage.

  • Age: As we age, the skin's natural pH tends to increase, leading to a weakened acid mantle. This can make the skin more susceptible to damage and irritation.

  • Underlying Skin Conditions: Eczema, psoriasis, rosacea, and acne already have a disturbed acid mantle and can further ruin it if not treated.

  • Unhealthy Lifestyle Habits: Poor diet, stress, lack of sleep, and smoking can affect overall skin health and contribute to a damaged acid mantle (obviously).

  • Genetics: Some individuals may have skin conditions that run in the family and should be aware of this when treating the acid mantle. This is not incurable though.

Why does a damaged acid mantle cause skin redness?

When the skin acid mantle is too alkaline, pathogens and environmental irritants can more easily damage the skin, making you red.

You skin should have a healthy microbiome on it with wonderful, beneficial bacteria on it. These bacteria prefer the acidity of your skins acid mantle. If your skin acid mantle is damaged these beneficial skin bacteria cannot survive and opportunistic bacteria can take hold on your skin. When these opportunistic bacteria take over on your skin barrier, depending on the bacteria, you will get something like acne, rosacea, redness, cystic acne, etc. It is well known that all skin conditions have a 'skin microbiome' problem.

🦠 Just like in the gut, if you make your skin an inhospitable place for problematic skin microbes (and even introducing beneficial microbes), your skin condition will improve. Problematic skin microbes do not thrive when the skin mantle is at its preferred pH of 4.7-5.75.

Helpful Acid and Microbes Concept: When you make any kind of ferment like a lacto-ferment or even yogurt, these fermentation products will have a beneficial microbial population AND an acidic environment. (My yogurt is at a pH of 4, check out my youtube.) Pathogenic microbes cannot survive when your ferment is healthy and acidic. Your skin is the same. Pathogenic microbes that make you red cannot hurt you when your skin is healthy and acidic. Having a healthy skin acidity level is essential to being less infected and red.

Using acidic skin products help address these types skin conditions.

What are examples of acidic skin products?

These are some examples of the ingredients you should look for.

🌾 Azelaic Acid (1st place for treating redness):

  • Azelaic acid is a dicarboxylic acid found in grains like wheat, barley, and rye.

  • It has anti-inflammatory and antimicrobial properties, making it effective in treating acne and rosacea.

  • Azelaic acid also helps reduce hyperpigmentation, improve skin texture, and control oil production.

  • Examples of products containing azelaic acid include prescription creams, gels, and over-the-counter serums.

Matt's note: Azelaic acid has the best reputation for treating redness. Personally, I prefer more natural, esoteric, skincare products. My most used skincare products are: homemade salty ocean water, honey, yogurt, tallow, and jojoba oil. Yogurt is the acid I use most with its natural lactic acid production.

🍋 Citric Acid (AHA):

  • Citric acid is an AHA derived from citrus fruits like lemons and oranges.

  • It's used in skincare products as an exfoliant, antioxidant, and pH adjuster.

  • Citric acid helps brighten the skin, fade dark spots, and improve overall skin tone.

  • Products containing citric acid include facial cleansers, peels, and brightening serums.

Matt's note: if Azelaic Acid isn't working for you then this could be your second choice.

🌾 Glycolic Acid (AHA):

  • Glycolic acid is an alpha hydroxy acid (AHA)

  • Glycolic acid derived from sugar cane.

  • It's widely used in chemical exfoliants and skincare products to improve skin texture, reduce fine lines and wrinkles, and promote a brighter complexion.

  • You'll find glycolic acid in toners, serums, peels, and moisturizers.

🥛 Lactic Acid (AHA):

  • Lactic acid is another AHA

  • Lactic acid naturally found in milk and fermented milk products like yogurt.

  • It's known for its exfoliating properties and is often used in skincare products to gently remove dead skin cells, improve skin tone and texture, and hydrate the skin.

  • Products containing lactic acid include exfoliating toners, creams, and masks.

Matt's note: Lactic acid is naturally produced by lactic acid bacteria. These bacteria are present in ferments such as yogurt. Matt really enjoys using yogurt topically.

🌳 Salicylic Acid (BHA):

  • Salicylic acid is a beta hydroxy acid (BHA) and is derived from willow bark.

  • Salicylic acid penetrates deep into the pores, exfoliates the skin, and unclogs pores.

  • This is best suited for acne-prone skin.

  • Examples of products containing salicylic acid include cleansers, spot treatments, and acne treatment pads

These are just a few examples of acidic skincare ingredients commonly used in various products. When starting with something new in your skin care routine do a small patch-test first, especially if you have sensitive skin.

Please see my blog post on acidic skin care products for more information.

Thanks so much for reading. As always, if you have questions, feel free to reach out via my website or comment below

Matt ☀️


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