Sensitive Skin Consensus of Famous Experts in China

Sensitive skin refers to a high reaction state skin under the situation of physiological or pathological conditions. It mainly happens on the face. Its clinical manifestation is that when stimulated by physical, chemical, mental and other factors, the skin is vulnerable to subjective symptoms such as scorching, tingling, itching and tension. Accompanied or not with erythema, scales, capillary dilatation and other objective signs. There is a high incidence of sensitive skin in all countries in the world. Due to the different survey methods, the incidence rate of reported skin varies greatly from 25.4% to 89.9% in Europe and about 50% in Australia. The incidence rate is generally higher in women than in men. American women range from 22.3 percent to 50.9 percent, Asian women range from 40 percent to 55.98 percent, and Chinese women are about 36.1 percent. With the aggravation of environmental pollution and the increase of mental pressure, its incidence is gradually increasing and people pay more and more attention to it. To improve the understanding of sensitive skin, regulate the behavior of diagnosis and treatment. The dermatology group of dermatology branch of Chinese medical association, cosmetic department of dermatology branch of Chinese medical association, Chinese association of traditional Chinese and western medicine dermatology branch photomedicine and skin barrier group specially formulated “The consensus of experts on diagnosis and treatment of sensitive skin in China”

1.The factors of sensitive skin

1.1 Individual factors

Sensitive skin causes complex problems. Individual factors include heredity, age, sex, hormone level and mental factors. Recent studies have shown that sensitive skin is genetically linked with heredity. Higher rates in the young than in the old, and higher rates in women than in men. Mental stress reflexively causes the release of neurohypopeptide. This causes sensitive skin.

1.2 External factors

The following factors can cause or aggravate sensitive skin①physical factors: such as seasonal change, temperature change, sun exposure, etc. ②chemical factors: such as cosmetics, cleaning products, disinfecting products, air pollutants, etc. ③Iatrogenic factors: such as external stimulants, long-term local use of large amounts of corticosteroids, some laser treatment after surgery.

1.3 Other skin diseases

Sensitive skin can also be secondary to certain skin diseases. About 66% of women with atopic dermatitis and 57% of rosacea patients have skin sensitivity. Others diseases such as acne, contact dermatitis, eczema, can also cause sensitive skin. This consensus does not cover sensitive skin caused by skin diseases.

2.Occurrencemechanism of sensitive skin

Current studies suggest that the occurrence of sensitive skin is a complex process involving skin barrier – nerve vessels – immune inflammation. Under the interaction of internal and external factors, the function of the skin barrier is impaired, causing increased sensory nerve afferent signals, resulting in increased skin responsiveness to external stimuli, and causing skin immune inflammatory responses.

2.1 Damage to skin barrier function

The incompleteness of the sensitive cuticle structure and the imbalance of lipid content between epidermal cells can lead to the decrease of ceramide content. Skin physiological indexes test showed that the skin moisture loss rate of sensitive skin increased through the epidermis, and the water content of the cuticle decreased, indicating that the function of sensitive skin barrier was impaired. Due to the skin surface temperature too low or too high (less than 34℃ or higher than 42℃) will delay the skin barrier to repair, so the environment temperature can trigger or worsen sensitive skin.

2.2 Cutaneous sensory nerve dysfunction

The protection ability of skin nerve endings is weakened, the density of nerve fibers is increased, and the reactivity of sensory nerves is increased. These three factors interact with each other, causing dermal sensory nerve dysfunction, which is related to the activation of the transient receptor potential family. Sensitive transient receptor potential subfamily members of the vanillin family can be activated by physiological or subphysiological temperature (lower than the normal activation temperature of TRPV1), which shows that temperature changes can cause burning, tingling and itching of sensitive skin. Because TRPV1 is easily activated by capsaicin, it is often called capsaicin receptor. The occurrence of sensitive skin is not only related to the abnormal peripheral nerve function, but also related to the change of central nerve function.

2.3 Increased vascular reactivity

TRPV1 is expressed in mast cells and keratinocytes, and endothelin is secreted by endothelial cells and mast cells and induces mast cell degranulation leading to neurogenic inflammation.ET-1 can induce tumor necrosis factor (TNF) – and interleukin-6 secretion, promote the production of vascular endothelial growth factor (VEGF), increase vascular reactivity and induce vascular dilatation.

2.4 Immune and inflammatory responses

TRPV1 activation can not only promote the local skin of neurotransmitter substance P, vasoactive intestinal peptide, nerve antihypertensive peptides and the release of pancreatic secretion but also leads to the formation of a sensory nerve endings near the cutin cell, mast cells release IL-23 and IL-31, and activate the antigen presenting cells and T cells, causing skin immune and inflammatory response.

3.Clinicalmanifestation of sensitive skin

3.1 Subjective symptom

After being stimulated by physical, chemical, spiritual and other stimuli, the skin presents symptoms of various degrees of heat, tingling, itching and tension, lasting for several minutes or even hours, and often cannot tolerate ordinary skin care products.

3.2 Objective signs

The appearance of sensitive skin is basically normal, the skin of a few people face can appear sheet or diffuse scarlet, erythema, capillary dilate, can accompany dry, small scale chip.

4.Assessmentmethod of sensitive skin

4.1 Subjective assessment

First of all, subjects were asked to self-evaluate the sensitivity of the skin according to whether they were prone to subjective symptoms such as scorching, tingling, itching and tension when they were stimulated by trigger factors, and determine whether they were sensitive skin. Possible triggers ①physical factors: such as seasonal change, temperature change, sun exposure; ②chemical factors: such as cosmetics, cleaning products, disinfectant products, vitamin A acid and other stimulating drugs, environmental pollutants (such as smog, dust, tail gas), etc. ③Mental factors: anxiety, depression, etc.

4.2 Semi-subjective assessment

As a semi-subjective method, stimulation test has been widely used in the determination of sensitive skin. Lactate stinging test and capsaicin test are commonly used.

4.2.1 Lactate stinging test

It is one of the most widely used evaluation methods, the most classic of which is the smear method. At room temperature, apply a 10% lactic acid solution of 50 L to the nasolabial groove and to any side of the cheek, The subjects were asked about their own symptoms at 2.5min and 5min respectively. The score was based on a four-point scale (0 for no tingling, 1 for mild tingling, 2 for moderate tingling, and 3 for severe tingling).Then the two scores were added together, and the total score greater than 3 was positive for lactate stinging reaction.

4.2.2 Capsaicin test

It is commonly used to evaluate sensorineural sensitive skin. Two layers of filter paper with a diameter of 0.8cm were placed on the filter paper about 1cm outside one side of the nasolabial groove and on any side of the cheek. The concentration of 0.1‰ capsaicin 50 was placed on the filter paper to ask the subjects how they felt(1 is barely perceptible, 2 is mild, 3 is moderate, 4 is severe, 5 is pain).If the burning sensation of the subject lasts for > 30S and the degree is greater than 3 points, the patient is positive.

4.3 Objective evaluation

Objective evaluation mainly applies non-invasive skin physiological index test, which can better reflect the severity of sensitive skin or the therapeutic effect. Commonly used quantitative indicators include(1)Transdermal water loss rate: it indirectly reflects the function of skin cuticular barrier, and the value of sensitive skin is often increased;(2)Water content of cuticle layer: it is often decreased in sensitive skin.(3)PH value: the pH value of sensitive skin is often increased.(4)Sebum: the sebaceous glands of the main source of sebaceous fat content, sensitive skin sebum often decreased;(5)Skin erythema index: the degree of erythema on the surface of the skin can be indirectly measured by skin chromaticity spectrometer.(6)Histogram of local blood flow velocity and blood flow distribution: color doppler flowmeter was used to determine local blood flow condition.

5. Diagnosis and differential diagnosis of sensitive skin

The diagnosis should meet the main conditions and the secondary conditions are for reference.

5.1 Main conditions

Including the following points:①subjective symptom: When skin is stimulated by physical, chemical, mental and other factors, it is easy to experience scorching, tingling, itching and tension; ②Exclude primary diseases that may accompany sensitive skin, such as rosacea, seborrheic dermatitis, hormone-dependent dermatitis, contact dermatitis, atopic dermatitis, and swollen lupus erythematosus.

5.2 Secondary conditions

Including the following points: ①physical signs: The skin appears moist red, erythema, telangiectasia and scaly; ②Subjective evaluation suggests sensitive skin; ③Semi-subjective assessment; ④Noninvasive tests of skin physiological indicators suggest abnormal changes in skin barrier function.

6. Treatment of sensitive skin

The general principles are to strengthen the healthy education, promote the repair of skin barrier, reduce the neurovascular hyperresponsiveness and control the inflammatory response, etc., with the aim of improving skin tolerance.

6.1 Health education

Sensitive skin is prone to recurrent attacks, psychological counseling and healthy education are very important. We should avoid all kinds of trigger factors as far as possible, such as sun exposure, eating spicy food, drinking, mood fluctuation, closed thermal environment and so on, and avoid abusing cosmetics. Then regular treatment and follow-up were conducted, and treatment was conducted under the guidance of doctors to maintain patience and confidence, so as to maintain a good skin condition.

6.2 Proper skin care

Repairing the damaged skin barrier is an important measure to treat sensitive skin. Proper skin care should follow the principle of gentle and clean, soothing and moisturizing, strict sun protection. It is advisable to choose medical skincare products with good safety after trial and clinical verification. Ban exfoliating products, appropriate to use warm water to clean the face, daily cleansing times should not be excessive. According to the seasonal change, medical skincare products with the function of repairing skin barrier are selected.

6.3 Physiotherapy

6.3.1 Cold spray, cold film and cold ultrasonic knife

Patient who is sensitive to thermal stimulation can reduce inflammation by contracting dilated capillaries through cold physical action.

6.3.2 Red light and yellow light

Red light has anti-inflammatory and repair skin barrier effects. Yellow light can promote cell metabolism and reduce the excitability of nerve fibers in the end. It can relieve and treat various symptoms of sensitive skin.

6.3.3 Strong pulse light and radio frequency

Strong pulsed light can close the dilated capillaries by thermal coagulation and promote the repair of skin barrier function by photoconditioning on epidermal cells, so as to relieve skin sensitive symptoms. RF can stimulate the proliferation of dermal type I, Ⅲcollagen, improve skin resistance.

6.4 Drug therapy

Patients with severe symptoms may be treated with medication as appropriate. Anti-inflammatory and antihistamine drugs may be used for patients with obvious burning, tingling, itching and tension. Antianxiety and depression drugs may be used as appropriate in patients with anxiety and depression.

7.Best solution of sensitive skin

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