Introduction
In recent years, more and more people report experiencing skin discomfort in response to common stimuli: redness, tingling, burning, or a sensation of skin "tightness." But what makes the skin suddenly so reactive? Understanding the causes of increased skin sensitivity is the first step to caring for it in the most correct and conscious way.
According to a study published in Journal of the European Academy of Dermatology and Venereology, about 60% of women and 40% of men report having sensitive skin. A significant figure that reflects a growing phenomenon due to environmental, cosmetic, psychological, and genetic factors.
In this article, we analyze in depth the factors that contribute to making the skin hypersensitive, drawing from scientific studies published in authoritative sources such as PubMed. We will explore biological, environmental, and behavioral components to offer a comprehensive view of the problem.
Skin barrier dysfunction: when the skin loses its defenses
The skin barrier is our first line of defense: a complex system made of lipids, keratinocytes, and proteins that protects against external agents and regulates water loss. When this barrier is damaged, the skin becomes more permeable, more vulnerable to environmental aggressors and potential irritants.
Factors such as too frequent washing with harsh cleansers, climate changes, or dermatological conditions (such as atopic dermatitis) can alter the integrity of the skin barrier. According to a 2021 study (Kelleher et al., PubMed ID: 33852256), a barrier dysfunction underlies 80% of sensitive skin cases in atopic patients.
Environment and climate: external agents that stress the skin
The environment we live in has a significant impact on our skin. Low temperatures, wind, variable humidity, sun, and air pollution are just some of the factors that can destabilize skin balance.
Pollution, in particular, has been associated with an increase in pro-inflammatory particles on the skin surface. Recent studies show that chronic exposure to fine particulate matter (PM2.5) can increase skin sensitivity by 35%, promoting irritation and redness (Li et al., 2022).
Stress: an invisible but real cause
Psychophysical stress alters hormonal and neurocutaneous balance, contributing to hypersensitivity. Cortisol, the stress hormone, compromises the lipid barrier and reduces local immune defenses, facilitating inflammatory reactions.
According to a 2020 study published in Frontiers in Psychiatry, patients with anxiety disorders show a higher incidence of dermatitis and symptoms related to sensitive skin (redness, tingling, flaking).
Hormonal factors: when internal balance changes
Hormonal fluctuations related to the menstrual cycle, pregnancy, menopause, or endocrine disorders (such as hypothyroidism) influence skin response.
The decrease in estrogen during menopause, for example, reduces collagen and lipid production, making the skin thinner and prone to dehydration. A 2019 Korean study found that 80% of post-menopausal women develop signs of sensitive skin within the first 5 years.
Genetics and personal predisposition
Those with a fair phototype or a family history of atopic dermatitis, allergies, or rosacea are more prone to develop skin reactivity. Genetic analyses have identified mutations in the gene FLG (filaggrin) as predispositions to skin sensitivity, as they influence the structure of the epidermal barrier.
Inadequate cosmetics: when skincare worsens the problem
Some cosmetic ingredients (alcohol, fragrances, preservatives) are highly sensitizing. In a 2021 dermatological survey, over 45% of subjects with sensitive skin had a negative reaction to a cosmetic product used in their daily routine.
Layering too many strong actives (such as exfoliating acids, retinoids, and unstable forms of vitamins) can cause pH imbalance and inflammation.
Preexisting skin conditions
Some chronic diseases make the skin more vulnerable. Rosacea affects about 10% of the European population and is associated with a lower sensory threshold. Psoriasis and seborrheic dermatitis alter both the skin structure and the microbiota, increasing reactivity to stimuli.
Allergic reactions and contact dermatitis
According to the EAACI (European Academy of Allergy and Clinical Immunology), 15-20% of the European population suffers from allergic contact dermatitis. These reactions, often caused by nickel, perfumes, or preservatives, cause inflammation that makes the skin more reactive even in the absence of the allergen.
The role of the skin microbiome
The microbiome, altered by antibiotics, unbalanced cosmetics, or dermatological conditions, plays a central role. A healthy microbial flora reduces inflammation and increases the skin's tolerance threshold. Recent studies suggest that reduced bacterial diversity is common in subjects with sensitive skin (Zeeuwen et al., Nature Reviews Microbiology).
Nerve endings and sensory hyperactivity
The skin hosts a complex network of nerve endings. In some cases, these fibers become hyperactive. Studies on small fiber neuropathy (Small Fiber Neuropathy) indicate that nerve hyperreactivity can explain symptoms such as burning and itching without visible signs.
A research published in Experimental Dermatology has shown that subjects with sensitive skin have a thermal stimulus tolerance threshold 20-30% lower than the control group.
Age and skin sensitivity: a cross-cutting issue
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Infants and children: their skin has an incomplete lipid barrier and a higher pH, making them particularly sensitive to cleansers and temperature changes.
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Adults: excessive use of cosmetics and environmental exposure are predominant factors.
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Over 60: the physiological reduction of sebum, collagen, and cell renewal increases skin vulnerability. 65% of women over 60 report typical sensitive skin symptoms.
Diagnosis and specific tests
Skin sensitivity is mainly diagnosed based on symptoms reported by the patient. However, there are useful instrumental tests:
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Lactic acid sting test: assesses subjective reactivity to chemical stimulus.
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Corneometry: measures the hydration of the stratum corneum.
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Transepidermal Water Loss (TEWL): checks transepidermal water loss, often elevated in sensitive skin.
These tools, although not routine, help identify physiological alterations associated with the condition.
Conclusion
Skin sensitivity is a multifactorial and cross-cutting condition that can affect all ages and phototypes. The causes go far beyond appearance and involve the immune, nervous, hormonal systems, and the external environment.
Relying on scientifically validated dermocosmetic protocols and choosing products free of sensitizing substances is essential to care for this condition in a targeted way.
To learn more about how to protect sensitive skin and intervene effectively, we also recommend reading: Causes of skin redness: how to protect sensitive skin.
Taking care of sensitive skin means listening to it every day. And choosing, wisely, what makes it feel good.
