of eight European countries, 49.4% women and 37% men declared having sensitive skin. Italy and France had the highest prevalence rate (Table 1). In Asia, women more frequently complaining about sensitive skin than men, and South Korea has the highest prevalence of sensitive skin compared to Japan and China (Table 1).
Questions have been raised as to whether there are differences between ethnic groups. A study conducted in the US on four ethnic groups (African Americans, Asians, Euro-Americans, and Hispanics) found a high prevalence of sensitive skin in the US, mainly associated with fair skin phototype, despite no statistical differences between these four ethnic groups.36 The study also found some differences in triggering factors and clinical symptoms; Asians expressed greater reactivity to spicy food, sudden temperature changes, wind, and experienced more frequent itchiness, while African Americans expressed moderate skin reactivity to the environmental factors and less frequency of recurring facial redness, which may be due to less visibility of erythema on darker skin (Table 1).
Different Associating Factors in Diverse Populations
Numerous internal and external factors either contribute to or trigger sensitive skin. Studies have found that sensitive skin has a higher prevalence in individuals with fair skin phototypes (Fitzpatrick skin type I and II in Caucasians; type III in Asians),36,37,38 but overall prevalence is similar across different ethnic groups with some differences regarding what triggers skin discomfort.36 The most reported triggering factors are weather conditions (cold, heat, humidity), air pollution, air conditioning, dry air, psychological stress, personal hygiene products, personal care products, and rough fabric clothing.39 Sun exposure also plays a role in triggering sensitive skin.37,40 In terms of gender, women have higher prevalence compared with men globally based on current epidemiology studies. However, a study conducted in 2018 with 5000 people in France has shown an increase in prevalence of sensitive skin with the increase larger in men than women in comparison to a study conducted in 2009 (Table 1). Regarding the body location, face is the most reported site of sensitive skin because of its dense nervous network and higher frequency of exposure to triggering factors. The clinical signs and symptoms associated with sensitive skin have been also reported to occur in conjunction with the menstrual cycle and have been shown to be correlated with high concentrations of estradiol or luteinizing hormone,39 this may in part explain the differences in skin sensitivity between women and men. Dry skin and susceptibility to blushing and flushing are also more likely to be associated with sensitive skin.35
Skin Barrier Impairment and Sensitive Skin
One of the leading hypotheses is that impaired epidermal barrier leads to increased trans-cutaneous penetration of substances and less protected cutaneous nerve endings, which results in heightened neurosensory response when experiencing environmental challenges or in contact with substances that normally do not cause irritation.41,42,43 In recent years, researchers have suggested that keratinocytes may act as a stimulus sensor that processes and transfers information to the C-fiber terminals.44 One of the receptor families present in keratinocytes is transient receptor potential (TRP), which acts as sensors for temperature or other physical or chemical factors.45
It has been confirmed that the impaired epidermal barrier leads to an increase in TEWL, a decrease in SC hydration status, which clinically manifests as dry skin, and sensitive skin is frequently reported by people with dry skin. Furthermore, people with skin barrier disorders such as AD, rosacea, acne, seborrheic dermatitis, irritant contact dermatitis, and allergic contact dermatitis, tend to experience some degree of sensitive skin symptoms.35
Studies also suggest people with sensitive skin may have a thinner SC with a reduced corneocyte area,46 an imbalance of intercellular lipid of SC,47 and lower SC ceramides contents;48 all of these can have a strong impact on epidermal barrier integrity. A study conducted in South Korea compared the amount of SC ceramides between the sensitive skin group and the non-sensitive group, and found that the amount of SC ceramides was significantly lower on facial skin in the sensitive skin group than in the non-sensitive skin group, and lower on the forearms, thighs, legs, and back skin in the sensitive skin group than in the non-sensitive skin group.48
Recently, a role of cutaneous microbiota in skin sensitivity had been hypothesized, and more studies are needed to demonstrate the link between skin sensitivity and skin microbiota.49
Sensitive skin as a dermatological condition can have a significant impact on affected individuals' quality of life.50 The management of sensitive skin sometimes can be very challenging due to its complicated contributing and triggering factors and pathogenesis.
Skin Barrier Restoration
The importance of lipids that form the epidermal barrier (equimolar ratios of sphingolipids, cholesterol, and free fatty acids) is demonstrated by the fact that disruption of skin barrier using physical (tape stripping) or chemical (acetone extraction) stimulates epidermal proliferation and lipid biosynthesis.51 In addition, it has been reported that topical application of ceramides, cholesterol, and essential/nonessential free fatty acids (FFAs) mixture in an equimolar ratio facilitates normal skin barrier recovery.52 These evidences strongly suggest utilization of physiologic lipids is an effective approach for compromised epidermal barrier-associated dermatological conditions (eg,
Questions have been raised as to whether there are differences between ethnic groups. A study conducted in the US on four ethnic groups (African Americans, Asians, Euro-Americans, and Hispanics) found a high prevalence of sensitive skin in the US, mainly associated with fair skin phototype, despite no statistical differences between these four ethnic groups.36 The study also found some differences in triggering factors and clinical symptoms; Asians expressed greater reactivity to spicy food, sudden temperature changes, wind, and experienced more frequent itchiness, while African Americans expressed moderate skin reactivity to the environmental factors and less frequency of recurring facial redness, which may be due to less visibility of erythema on darker skin (Table 1).
Different Associating Factors in Diverse Populations
Numerous internal and external factors either contribute to or trigger sensitive skin. Studies have found that sensitive skin has a higher prevalence in individuals with fair skin phototypes (Fitzpatrick skin type I and II in Caucasians; type III in Asians),36,37,38 but overall prevalence is similar across different ethnic groups with some differences regarding what triggers skin discomfort.36 The most reported triggering factors are weather conditions (cold, heat, humidity), air pollution, air conditioning, dry air, psychological stress, personal hygiene products, personal care products, and rough fabric clothing.39 Sun exposure also plays a role in triggering sensitive skin.37,40 In terms of gender, women have higher prevalence compared with men globally based on current epidemiology studies. However, a study conducted in 2018 with 5000 people in France has shown an increase in prevalence of sensitive skin with the increase larger in men than women in comparison to a study conducted in 2009 (Table 1). Regarding the body location, face is the most reported site of sensitive skin because of its dense nervous network and higher frequency of exposure to triggering factors. The clinical signs and symptoms associated with sensitive skin have been also reported to occur in conjunction with the menstrual cycle and have been shown to be correlated with high concentrations of estradiol or luteinizing hormone,39 this may in part explain the differences in skin sensitivity between women and men. Dry skin and susceptibility to blushing and flushing are also more likely to be associated with sensitive skin.35
Skin Barrier Impairment and Sensitive Skin
One of the leading hypotheses is that impaired epidermal barrier leads to increased trans-cutaneous penetration of substances and less protected cutaneous nerve endings, which results in heightened neurosensory response when experiencing environmental challenges or in contact with substances that normally do not cause irritation.41,42,43 In recent years, researchers have suggested that keratinocytes may act as a stimulus sensor that processes and transfers information to the C-fiber terminals.44 One of the receptor families present in keratinocytes is transient receptor potential (TRP), which acts as sensors for temperature or other physical or chemical factors.45
It has been confirmed that the impaired epidermal barrier leads to an increase in TEWL, a decrease in SC hydration status, which clinically manifests as dry skin, and sensitive skin is frequently reported by people with dry skin. Furthermore, people with skin barrier disorders such as AD, rosacea, acne, seborrheic dermatitis, irritant contact dermatitis, and allergic contact dermatitis, tend to experience some degree of sensitive skin symptoms.35
Studies also suggest people with sensitive skin may have a thinner SC with a reduced corneocyte area,46 an imbalance of intercellular lipid of SC,47 and lower SC ceramides contents;48 all of these can have a strong impact on epidermal barrier integrity. A study conducted in South Korea compared the amount of SC ceramides between the sensitive skin group and the non-sensitive group, and found that the amount of SC ceramides was significantly lower on facial skin in the sensitive skin group than in the non-sensitive skin group, and lower on the forearms, thighs, legs, and back skin in the sensitive skin group than in the non-sensitive skin group.48
Recently, a role of cutaneous microbiota in skin sensitivity had been hypothesized, and more studies are needed to demonstrate the link between skin sensitivity and skin microbiota.49
Sensitive skin as a dermatological condition can have a significant impact on affected individuals' quality of life.50 The management of sensitive skin sometimes can be very challenging due to its complicated contributing and triggering factors and pathogenesis.
Skin Barrier Restoration
The importance of lipids that form the epidermal barrier (equimolar ratios of sphingolipids, cholesterol, and free fatty acids) is demonstrated by the fact that disruption of skin barrier using physical (tape stripping) or chemical (acetone extraction) stimulates epidermal proliferation and lipid biosynthesis.51 In addition, it has been reported that topical application of ceramides, cholesterol, and essential/nonessential free fatty acids (FFAs) mixture in an equimolar ratio facilitates normal skin barrier recovery.52 These evidences strongly suggest utilization of physiologic lipids is an effective approach for compromised epidermal barrier-associated dermatological conditions (eg,
