Part 1. Why Your Skin Reacts to Everything

Written by Dr. Jun Oh

If your skin burns, stings, or flakes no matter what skincare product you try even the “clean,” “hypoallergenic,” or “natural” ones you’re not alone. You may have what researchers call extremely sensitive or reactive skin.

While most people with sensitive skin can find products that work with some trial and error, 10–20% of sensitive skin cases fall into a much more reactive category  one where even tiny amounts of common skincare ingredients can cause irritation.

So what’s happening beneath the surface? Let’s dive into the science behind why most products even gentle ones can’t help your skin (and may actually make it worse).

1. A Broken Barrier: Why Your Skin Lets Everything In

Healthy skin has a tightly packed, lipid-rich outer layer called the stratum corneum. It acts as a natural barrier that keeps irritants out and moisture in.

But in extremely sensitive skin, that barrier is compromised. The skin’s lipids are depleted, and key proteins like claudin-1 and occludin — which hold skin cells together are under-expressed [1]. The result? Small molecules, including “safe” ingredients, penetrate too easily. This causes overstimulation of nerve endings and immune cells, leading to stinging, itching, redness, and dryness.

2. Your Skin’s Immune System Is On High Alert

Reactive skin isn’t just thinner or drier — it’s immunologically hypersensitive.

Specialized immune cells in the skin, like Langerhans cells, are overly reactive in people with reactive skin. These cells release inflammatory chemicals (cytokines) in response to even low-level exposure to:

• Natural essential oils
• Preservatives (even ones considered “gentle”)
• Emulsifiers and surfactants
• Fragrance or pH stabilizers

This is not a traditional allergy. It’s a non-specific inflammatory overreaction that causes flare-ups in response to ingredients that others tolerate well [2][3].

3. Most Skincare Is Designed for Healthy Skin — Not Broken Skin

Most commercial skincare assumes that your skin barrier is intact. Even “hypoallergenic” or “natural” creams often include ingredients that are only safe if your skin can regulate what gets through.

But in reactive skin, barrier function is impaired, so ingredients that should stay on the surface penetrate deeper than they should, reaching layers of the skin where they trigger inflammation [4].

This explains why even clean or organic products can cause burning or redness in extremely sensitive skin.

4. What Reactive Skin Really Needs

To heal and protect reactive skin, you need more than just “gentle” products. You need formulations built specifically for compromised skin:

• Barrier-repair ingredients like panthenol, ceramides, and zinc
• High-molecular-weight humectants like beta-glucan and sodium hyaluronate that don’t penetrate too deeply
• Non-disruptive preservatives, such as those derived from probiotics, that won’t damage your microbiome
• Products that mimic the skin’s own lipid structure rather than overpower it with actives [5][6]

Coming next:

The 5 Best and Worst Skincare Ingredients for Reactive Skin

Let’s stop guessing and start helping skin that truly needs care.

Drop your email here to get updates.

References

1. De Benedetto, A., et al. (2011). Tight junction defects in atopic dermatitis. Journal of Allergy and Clinical Immunology, 127(3), 773–786.e7. https://doi.org/10.1016/j.jaci.2010.10.018
2. Czarnowicki, T., et al. (2014). Innate immune activation in atopic dermatitis: pathophysiologic and therapeutic implications. Journal of Allergy and Clinical Immunology, 134(2), 300–308. https://doi.org/10.1016/j.jaci.2014.06.013
3. Egawa, G., & Kabashima, K. (2018). Barrier dysfunction in the skin: Causes and consequences. Journal of Dermatological Science, 90(3), 231–239. https://doi.org/10.1016/j.jdermsci.2018.03.003
4. Draelos, Z. D. (2008). Sensitive skin: Perceptions, evaluation, and treatment. American Journal of Contact Dermatitis, 19(1), 8–13. https://doi.org/10.1111/j.1525-1470.2008.00217.x
5. Voegeli, R., et al. (2007). The effect of prolonged use of moisturizers on skin barrier function and skin susceptibility to irritants. Dermatology, 214(2), 154–162. https://doi.org/10.1159/000098081
6. Proksch, E., Brandner, J. M., & Jensen, J. M. (2008). The skin: an indispensable barrier. Experimental Dermatology, 17(12), 1063–1072. https://doi.org/10.1111/j.1600-0625.2008.00786.x