A deep dive into sensitive skin

When it comes to skin health, sensitive skin should be considered a priority within beauty and personal care.

Sensitive skin conditions are highly prevalent worldwide with 37% of the population affected – including 44% the US population, and 51% of women and 38% of men in the UK [1].

There are many different types and symptoms, and the prevalence of skin conditions such as atopic dermatitis, acne and psoriasis have been estimated to be 2–4 times higher in individuals with sensitive skin [1].

However, much more work is needed to gain a full understanding of the triggers and underlying physiological processes, as well as how these factors interact with the skin microbiome.

Here, we will take you on a sensitive skin deep dive to explore what is known so far (also building on our recent Skin Health 101).

What is sensitive skin?

Sensitive skin is not a single condition but describes skin that is hypersensitive – resulting in abnormal sensory perceptions such as stinging, burning, tingling, pain and itching, and low tolerance to beauty and personal care products [2,3].

The mechanics of sensitive skin are not yet fully understood [4], but a few different underlying processes have been identified that are thought to contribute to the various types of sensitive skin [5,6,7]. It is important to note that although often confused, sensitive skin differs to irritated and allergic skin, which are different conditions arising due to environmental factors [8].

Here we will explore skin barrier structure and function and the skin neurosensory network as two key examples, showing how these two mechanisms interact…

Skin barrier disruption

A disrupted skin barrier is thought to lead to skin sensitivity as altered concentrations of structural lipids and disturbances across other skin barrier components can cause skin discomfort. Increases in sphingolipids, which are key for skin tissue development, have been linked to reduced skin barrier stability [6].

People with sensitive skin also have a thinner stratum corneum (the outermost layer of skin) with reduced corneocyte numbers (a type of skin cell – refer back to our Skin Health 101 article for a backgrounder on skin structure), increasing the permeability of our skin [9]. An imbalanced skin pH is another factor that can contribute, as the enzymes responsible for producing key lipids such as ceramides, which are critical to the permeability of our skin barrier, need acidic pH to function [10].

A skin barrier that is weakened in this way facilitates the penetration of irritants or allergens, and has elevated transepidermal water loss (TEWL) – all of which can lead to skin discomfort [6].
In line with this, the use of moisturizing creams and balms that work to elevate the amount of lipids, normalize TEWL and balance pH can restore and protect skin barrier integrity and reduce the effects of sensitive skin [11].  

Skin neurosensory disruption

Although a strong skin barrier is key for protection from sensitive skin triggers such as elevated TEWL and penetration of irritants, its structure disruption alone cannot explain the full symptoms associated with sensitive skin conditions [9] – remember the burning, tingling, stinging, pain and itching. The skin’s nervous system has also been identified as a key player. For example, skin sensations might result from insufficient protection of nerve endings in the skin due to an impaired skin barrier, or from a higher number of nerve fibres in the skin. Atopic dermatitis, for instance, can cause itching and tingling, and has been linked to higher skin nerve densities compared to individuals with healthy skin [6].

A role for sensory proteins, which are located on the surface of skin cells and nerve endings within the skin, has also been shown [9]. The function of these proteins is to allow us to sense and perceive the external environment. One key protein responsible for such sensory perceptions is the transient receptor potential cation channel subfamily V member 1 (TRPV1). TRPV1 can be activated by both physical (e.g. temperature) and chemical (e.g. cosmetic) factors, and have been found to be exposed or in present in high numbers in sensitive skin [9].

People with sensitive facial skin, for example, may experience stinging when exposed to capsaicin [4] – a compound found in chilli peppers that is also used to relieve pain in conditions such as arthritis and psoriasis [12] – due to exposed TRPV1 in the skin. This altered sensory experience was also linked to a disrupted skin barrier function with premature skin shedding and regeneration thought to lead to a thinner and immature stratum corneum, which enabled greater penetration of capsaicin and increased skin sensitivity [4].

What triggers sensitive skin?

Our skin is subject to numerous factors that are thought to contribute to sensitive skin conditions.

Varying by type and symptom, sensitive skin can also occur as part of the symptoms associated with skin disorders, or independently within normal skin as a result of physical factors (such as UV radiation, heat, cold and wind), chemical factors (cosmetics, soap, water and pollution), lifestyle factors (diet and alcohol consumption), psychological factors (stress) and hormonal factors (menstrual cycle) [5,6,7]. 

We will explore a few examples here to show the breadth of factors that put us at risk…

Skin disorders

Sensitive skin can manifest as part of the symptoms associated with skin disorders (particularly on facial skin) [2] – with higher prevalence of sensitive skin found in association with conditions such as atopic dermatitis, psoriasis, acne, rosacea and seborrheic dermatitis [2,3].

The prevalence of sensitive skin in patients with rosacea can be as high as 100% [13], and more than 40% of psoriatic patients experience symptoms and signs of sensitive skin, such as itchy, hot and burning sensations, tenderness and cramping [14] – it has been estimated that the odds of having sensitive skin is 3.7 times greater if you have psoriasis [15].

Similarly, the odds of having sensitive skin are 2.5 times greater in patients with acne [15], and people with sensitive skin are five times more likely to experience skin allergies [16].

Like skin disorders, skincare products and medications administered to help with treatment and management, can induce symptoms and signs of sensitive skin [17,18].

Environmental conditions

Many environmental conditions have been linked to sensitive skin, as they can activate or worsen the underlying physiological mechanisms. Seasonal climate variation, for instance, can exacerbate sensitive skin as factors such as TEWL and skin pH vary between winter and summer [7]. Skin dehydration and a damaged skin barrier can result from high temperatures or dry conditions [19], and air conditioning can also contribute [20].

Moreover UV radiation has been identified as potential contributing factor as sensitive skin is more prevalent during summer, when we undergo higher UV exposure. In support of this theory, fair-skinned individuals prone to sunburn have reported increased discomfort compared to those with darker skin [6].

Where we live may also make a difference – with worsening air quality in many of the world’s cities and towns, pollutants such as particulate matter, nitrogen and sulfur oxides, ozone and polyaromatic hydrocarbons can act as irritants and damage the skin, resulting in sensitive skin [21].

Lifestyle factors

The list of lifestyle factors that have been identified to contribute to sensitive skin is broad. Sensitive skin conditions have been linked to sleep deprivation and sleep disorders, as well as dietary choices and alcohol and tobacco consumption [22].

Sensitive skin is also common in pregnant women, women with painful menstruation and women using contraceptive pills – suggesting that sensitive skin can be the result of wider body disruption, in these cases activated by heightened inflammation, and not just initiated within the skin itself [22].

Beauty and personal care products

Beauty and personal care products are a key triggering factor for sensitive skin due to their widespread use around the world [20].

The presence of potentially irritating substances in cosmetic products (such as alcohols, fragrances, preservatives) that penetrate the skin can initiate inflammation and lead to sensitive skin symptoms [23], and overuse of products also plays a part – women with sensitive skin have been shown to be more frequent users of liquid soap and gel cleansers than those without sensitive skin, and to use more product per application [24]. Women have also been found to wash their face more thoroughly than men, which is likely to disrupt skin barrier function [25].

Men experience additional challenges in the form of shaving-induced facial skin irritation. Male facial skin is diverse in morphology and roughness, and hair follicles act as sensory organs that respond to mechanical and thermal stimulation – potentially leading to irritation that is further heightened in men prone to skin sensitivity. Techniques commonly employed to avoid shaving-induced skin irritation include shaving with less pressure, use of pre- and post-shave skin treatments, and to shave less frequently or to stop shaving altogether [26]. 

This highlights the importance for people with sensitive skin to carefully select gentle products – buying products specifically formulated for sensitive skin, and products from pharmacies rather than supermarkets, can help minimize the effects [24].

Hereditary effects

Although sensitive skin is generally considered a consequence of environmental and lifestyle factors, a hereditary component in sensitive skin has recently been found.

Children who have a mother with sensitive skin have an elevated risk of experiencing sensitive skin themselves, and having sensitive skin during childhood has been linked to having sensitive skin as an adult – with symptoms such as dry skin and certain triggers being common throughout an individuals life [27]. 

Sensitive skin and the skin microbiome

Our skin harbours a diverse array of microorganisms that are key to maintaining a stable skin environment, helping to regulate processes such as our skin’s immune response and the proper expression and functioning of biomolecules [28,29].

In line with this, there is much evidence linking disruption within our normal, resident skin microbiome to skin conditions such as atopic dermatitis, rosacea and psoriasis, and acne [2]. However, when it comes to sensitive skin, although a link has been shown between skin microbiota disruption and variations in factors such as skin pH, the role of our skin microbiota is not yet well understood.

No clear differences have yet been found in the presence of our resident skin microbes (such as Actinobacteria, Proteobacteria and Corynebacterium) in sensitive skin [30,31], except for some slight variations in Staphylococcus epidermis whose numbers was shown to be lower in people with sensitive skin [28].

Despite the current lack of evidence, given the influence of our skin microbiome in other skin conditions as well as the prevalence of sensitive skin conditions across the world, more research in this area is key!

Explore more microbiome basics in the How it works section of the Content Hub and follow us on Instagram for the latest updates!

References

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