The scientific literature shows a worldwide increase in the prevalence of sensitive skin in recent years.4,9,12–15

The estimated prevalence in Japan, Europe, and the United States is 50% among women and 30% among men, with a similar distribution across countries and continents.6

In a telephone survey conducted in several European countries (France, Italy, Portugal, Germany, Switzerland, Belgium, and Greece), 37.6% of those interviewed (n=4506) reported having sensitive or very sensitive skin.13

Sensitive skin is also very common in Spain, with over 11 million Spaniards (35.4% of women and 27.9% of men) claiming that they have sensitive or very sensitive skin.16

Many studies have investigated possible associations between sensitive skin and sex, race, or age,4,6 but with inconsistent results.6

With respect to sex-related differences, the general perception is that more women claim to have sensitive skin than men,2,4 but some authors have reported a significantly higher prevalence among men.6

Farage2 reported that the perceived severity of sensitive skin was comparable in men and women, but that men perceived less severe reactions on the face. She also found that men and women cited different causes for their condition, with 15% of women and 11% of men linking it to irritation due to cosmetic products, and 9% of men and just 4% of women linking it to contact as a result of friction or rubbing.

Shaving appears to be the most common factor associated with sensitive skin in men. In a study conducted in France, 41% of men interviewed reported sensitive skin symptoms after shaving.17

An interesting association has been detected between sensitive skin and urinary incontinence in women, with one epidemiological study showing a significantly higher proportion of women over 50 years old with light urinary continence claiming to have sensitive skin compared to a control group matched for age and sex.18 Interestingly, the women with incontinence (n=29) but not the controls reported less skin sensitivity in the genital area than overall.

Several studies have suggested that black people have less sensitive skin than white people, and that white people, in turn, have less sensitive skin than Asians. There is, however, no statistical evidence to support these hypotheses, and the differences that have been detected between different ethnic groups are probably not race-related but rather due to pyschosocial4 and cultural factors4,6 (eg, personal hygiene practices4,6 and diet). Asians, for example, have stronger skin reactions to spicy food.6 Two studies have evaluated the intensity of reactions to capsaicin in different ethnic populations. In the first study, African Americans showed a limited hypersensitivity after the topical application of capsaicin (no significant changes in heat detection threshold, pain intensity, or skin blood flow), while East Asian, Hispanic, and white participants experienced significant changes in hyperalgesia and vasodilatation.19 In the second study, only minimal differences were detected between Asian, African, and white women in the capsaicin skin neurosensitivity test.20

Age can have a considerable influence on susceptibility to sensitive skin, and some studies suggest that young people are more prone than older people. In a study carried out in France, 52% of 1006 individuals reported having sensitive skin.6

The data support the observation that sensitive skin is a common condition and that its frequency decreases with age.17

The lack of studies analyzing sensitive skin in children is noteworthy, particularly considering the growing number of personal care products on the market specifically targeting this population.4 Indeed, the medical literature contains no analyses of sensitive skin in children.4 It should also be noted that the body surface area to body mass ratio is very high in children, which means that they are subject to high exposure to skincare products21 and therefore possibly more prone to sensitive skin.

The use of cosmetics that are unsuitable for a particular skin type is the most common exogenous factor that can trigger sensitive skin.9

Many cosmetic formulations contain alcohol, propylene glycol, butylene glycol, cocamidopropylbetaine, triethanolamine, resorcine,22 trichloroacetic acid, and alpha hydroxy acids, which, depending on their concentration, have a greater or lesser irritant effect and can aggravate sensitive skin.9 Topical corticosteroids increase skin fragility and cause chronic, localized erythema, leading to increased cosmetic intolerance and possibly triggering symptoms of sensitive skin in the affected area.4,9 UV-A exposure and surgical or nonsurgical cosmetic procedures, such as phototherapy, dermabrasion, laser resurfacing and facelifts, can all aggravate sensitive skin.9

A reduction in the skin's tolerance threshold not directly related to immunologic or allergic mechanisms has been observed in individuals with sensitive skin.5

Furthermore, the wide variety of sensory symptoms that have been identified in these individuals suggests sensory dysfunction of the nerves of the skin5 and a lowering of the nerve response threshold.6 Inadequate protection of nerve endings4 leads to increased sensitivity to irritants and exogenous stimuli.9

The mechanism that triggers the nerve response is reflected in modified cerebral activity. A study in which women underwent a simple blind test involving the application of lactic acid to the nasolabial fold while being monitored by magnetic resonance imaging, revealed the existence of a specific response in the central nervous system, suggesting that the excitability mechanism in sensory epidermal nerves on the face triggers cerebral activity that is very similar to that observed in skin pain processes.5

Recent studies have shown that the transient receptor potential vanilloid 1 (TRPV1) contributes to the expression of sensitive skin symptoms by facilitating neurogenic inflammation and leading to hyperalgesia.30

Muizzuddin et al28 found that skin of East Asians, and of whites to a certain extent, was characterized by low maturation and a relatively thin skin barrier, while that of African Americans was characterized by low ceramide levels and high cohesion in the upper layers of the stratum corneum.28 Those authors suggested that these differences might explain the disparity between East Asians and African Americans in the prevalence of sensitive skin.

Another study in patients with sensitive skin detected a correlation (r[s]=-0.47; P<.001) between the intensity of symptoms and the irregularity skin index.29

It has been established that the abnormal penetration of irritant substances into the skin due to altered barrier function triggers the symptoms of sensitive skin.9

Results obtained using a recently developed procedure based on the plastic occlusion stress test and measurement of TEWL desorption curves to assess skin barrier integrity in individuals with sensitive skin support the hypothesis that skin sensitivity is associated with greater barrier function impairment.31

Impaired skin barrier function increases the permeability of the stratum corneum.4,6,9

Alterations in intercellular lipids have also been reported in disorders such as atopic dermatitis and seborrheic dermatitis, in which the skin tolerance threshold is reduced by alterations in intercorneocytic lipids9; the stratum corneum is also thinner in such cases.4,9

Individuals with high subjective skin sensitivity experience an almost continuous sensation of tingling, burning, stinging, and tightness of the skin,32 although the intensity of symptoms varies greatly from one individual to the next.

Variations in sensitivity by anatomic site have also been identified.33 While the face is the most common site for sensitive skin,6 a study by Saint-Martory et al34 found that other parts of the body are also affected, namely the hands (58%), the scalp (36%), the feet (34%), the neck (27%), the torso (23%), and the back (21%). The above findings are supported by the results of studies that have identified neurosensory and physiological differences in the skin of different parts of the body.4

• 1.

  The face. In a study by Farage33 in 2009, 77.3% of individuals with sensitive skin claimed that they had sensitive facial skin; the percentages for those reporting sensitive body skin and sensitive genital skin were 60.7% and 56.3%, respectively. The only significant difference found on analyzing the results by sex, ethnic origin, and age was that a higher proportion of women and African Americans reported sensitive skin in the genital area. The facial area is probably affected most by sensitive skin because of the high number of cosmetic products used on the face and the fact that it has a weaker skin barrier than other parts of the body as well as a large number of nerve endings.12 The nasolabial fold is considered to be the most sensitive part of the face due to the permeability of its stratum corneum, its high density of sweat glands and hair follicles, and its rich innervations.4 The next most sensitive areas are the malar eminence, the chin, the forehead, and the upper lip.13

• 2.

  The scalp. Misery et al35 assessed scalp sensitivity in a sample of 1011 individuals; of these, 44.2% claimed that they had a sensitive scalp, and within this group, 11.5% had a scalp disease. There was a significant association between hair loss and scalp sensitivity. Prickling, itching, and pain were more common in the sensitive skin group, and the main triggers were pollution, heat, emotions, and shampoo. The authors found no association between scalp sensitivity and skin sensitivity in other parts of the body. Based on their findings, Misery et al. concluded that scalp sensitivity was a genuine, common condition. A subsequent study reported that the most common symptoms associated with sensitive scalp were itching and tingling and also stated that dandruff could not be considered a symptom of sensitive skin.36

• 3.

  The vulvar region. The vulvar region has particular anatomic characteristics that appear to make it more prone to irritation, but as Farage and Maibach12 have indicated, there is very little evidence supporting an association between female hygiene products and sensitive skin. In another study, Farage37 remarked that while topical agents frequently cause vulvar irritation, their irritant action is often underestimated. In a group of patients with chronic vulvar irritation, 29% were found to have contact hypersensitivity, while 94% reported secondary sensitization to topical medication.38 As concluded by Farage and Maibach,12 vulvar sensitivity is often related to contact hypersensitivity, which, in turn, is related to the use of topical medication and hygiene products.

Sensitive skin is associated with a wide range of nonspecific clinical signs, including erythema, telangiectasis, and scaling.3,32,39

Individuals with sensitive skin can also present clinical signs typically associated with concomitant conditions such as acne, contact dermatitis, psoriasis, rosacea, atopic dermatitis, seborrheic dermatitis, and vitiligo.

Sensitive skin has considerable psychological effects, and has been seen to adversely affect quality of life, with greater impairment seen in individuals with more sensitive skin.10 Zafiriou et al11 observed an association between skin hypersensitivity and somatization, anxiety, phobic anxiety, hostility, and interpersonal sensitivity.

One of the questionnaires used to evaluate sensitive skin was designed by Querleux et al. (Table 1)5; the questions are related to the typical characteristics of very sensitive skin and contemplate reactions due to the topical application of personal hygiene products and environmental factors.

Misery et al35 proposed the 3S questionnaire as an appropriate, effective tool for assessing the severity and symptoms of scalp sensitivity.

Many attempts have been made to find a test capable of providing an objective diagnosis of sensitive skin, but none of the tests analyzed have proven to be sufficiently effective, highlighting, once again, the subjective nature of sensitive skin.3,9

Farage et al4 reviewed the available tests for the assessment of sensitive skin and classified them into 3 major groups: (1) those that assessed neurosensory responses (sensory reactivity tests); (2) those that assessed visible signs of skin irritation (irritant reactivity tests); and (3) those that measured structural and physiological parameters of the skin as indicators of the irritant effect (dermal function tests).4

The stinging test designed by Frosch and Kligman40 is considered to be the most effective. It involves the application of 0.5mL of 10% lactic acid to one nasolabial fold and distilled water at room temperature to the other. The symptoms, assessed subjectively, are scored on a scale of 1 to 4 according to intensity.6,9 Other substances used in this test are capsaicin, ethanol, menthol, sorbic acid, and benzoic acid.4,9 The stinging test is considered to be the best way to diagnose sensitive skin.4,9 Furthermore, it is fast, cheap, and simple,4 although most authors generally agree that it lacks predictive value. Marriot et al39 indicated that a positive stinging test result in the nasolabial fold does not necessarily predict subjective responses to products applied to other parts of the face.

The plastic occlusion stress test combined with the measurement of TEWL desorption curves provides a more objective assessment of sensitive skin.31 It is a new, dynamic approach, which, unlike baseline TEWL measurements, provides unequivocal evidence of skin barrier impairment.31 Accordingly, it would seem that this test could be used to diagnose or predict sensitive skin.31Pons-Guiraud9 recommends including cosmetics and personal care products used by patients in allergy tests to detect subclinical manifestations of contact allergy. Should any signs of sensitive skin be detected, the author recommends withdrawing all cosmetics and reintroducing them, one by one, at 2-week intervals, and notes that it is important to limit the type of cosmetics used and the frequency with which these are applied in the final stage of the program.9

Topical corticosteroids are the most effective medical treatment for sensitive skin, although they must be used in moderation due to the risk of adverse effects such as skin thinning and impairment of skin barrier function.42

Topical calcineurin inhibitors are also effective. While they do not cause the adverse effects observed with corticosteroids, they are associated with numerous adverse reactions, such as itching and burning at the application site, although these tend to be mild and transient.42

There are numerous cosmetic treatments available for sensitive skin. Muizzuddin et al43 found that the use of products containing minimal preservatives and no surfactants for 8 weeks led to a change in the characteristics of sensitive skin, with improved skin barrier function and similar reactivity to that seen in nonsensitive skin. Moisturizers have also been seen to have a positive effect on sensitive skin as they improve skin hydration, reduce susceptibility to irritation, and restore the integrity of the stratum corneum.44

Draelos41 and Pons-Guiraud9 recommend the use of products specially designed for sensitive skins; these contain few ingredients and irritants and no common sensitizers or cutaneous sensory or vasodilatory stimulants.

Advances have been made in recent years on a new treatment approach involving a novel bioactive, trans-4-tert-butylcyclohexanol. Kueper et al30 described how this selective transient receptor potential cation channel subfamily V member 1 (TRPV1) antagonist was capable of inhibiting capsaicin-induced activation. The authors found that 0.4% trans-4-tert-butylcyclohexanol significantly reduced capsaicin-induced burning in a clinical study of 30 women tested with a topical emulsion containing 31.6ppm of capsaicin.

Treatment with Rhodiola rosea extract/l-carnosine–associated compound (RCAC) has been seen to protect skin barrier function and improve subjective responses in patients with sensitive skin.45

The effectiveness of this compound was demonstrated in a study by Dieamant et al45 by a reduction in TEWL, an improvement in hydration and the sensation of skin comfort, and a reduction in stinging test discomfort. The authors showed, in vitro, that the positive in vivo responses were due to a significant increase in the release of opioid peptides, an inhibitory effect on the production of neuropeptides, and the modulation of cytokine production by keratinocytes subject to ultraviolet stress.

Soap is one of the toiletry products that cause most skin reactions, and the problem is particularly acute among individuals obliged to wash their hands frequently. In such case, dermatologists need to recommend suitable cleansers,46 and the best choice appears to be an alcohol gel with moisturizer. These gels are designed to maintain skin barrier integrity, relieve dryness, and restore barrier function. The combined use of soap-free cleansers and topical treatments has been shown to lead to clinical improvement in patients with sensitive skin.44

Merinville et al47 proposed using sodium salicylate instead of salicylic acid in antiaging creams for sensitive skins; salicylic acid, which is usually present in high concentrations in antiaging products, can cause adverse effects such as somatosensory and visible irritation. Those authors reported that, compared to placebo, sodium salicylate caused a significant increase in fibrillin and collagen-1 antiaging biomarkers and significantly reduced wrinkle depth and skin redness after 4 and 8 weeks of daily application.

It has been suggested that hydroxy acids, which are a common ingredient in antiaging creams and are considered to be strongly irritant for sensitive skin, should be replaced by polyhydroxy and bionic acids as these offer the same benefits as hydroxy acids but do not cause skin irritation; furthermore, they provide additional antioxidants, strengthen the skin barrier, and have moisturizing effects.48

Neukam et al49 recommended dietary supplementation with flaxseed oil as preventive treatment for sensitive skin. They showed that this supplement significantly reduced sensitivity after nicotinate irritation, skin redness and scaling, and also improved smoothness and hydration.

Pons-Guiraud9 has recommended a set of guidelines for the prevention and management of sensitive skin (Table 2).

Importantly, all treatment approaches should include the recommendation to avoid, where possible, triggers of sensitive skin symptoms, and, as Pons-Guiraud has stated, this requires “cooperation from the patient and tenacity from the physician”.9