What Is Leukoplakia?

The skin is divided into epidermis, dermis, and hypodermis

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White spot disease is a general term for some diseases with white spots on the skin as the main symptom in medicine.

Physiological structure of leukoplakia

The skin is divided into epidermis, dermis, and hypodermis

Skin physiological structure diagram

The epidermis is the superficial structure of the skin and is composed of stratified flat epithelium. From the inside to the outside, they are: basal layer, spinous layer, granular layer, transparent layer and stratum corneum.

The dermis is located on the deep side of the epidermis and consists of dense connective tissue. Divided into nipple layer and reticular layer.

The production of melanin by melanocytes produces some intermediate products that are toxic to melanocytes, causing the destruction or damage of melanocytes. The incidence of vitiligo tends to increase year by year. One of the reasons may be related to the increasing production and use of some phenolic compounds in the industry.

Structure and function of white skin epidermis

1. Basal layer: is a layer of short columnar epithelial cells, which is located at the bottom of the epidermis and connected to the dermis. It is the only cell in the epidermis that can divide and replicate. The cell division of the basal layer is relatively active, and new cells are constantly generated and pushed to the superficial layer to supplement aging and exfoliated keratinocytes. It takes about 28 days for the production of an epidermal cell to gradually pass to the epidermal stratum corneum and die off. This is also the metabolism cycle of the epidermal cell. There are melanin cells in the basal layer and produce melanin particles. The number of melanin particles is directly related to the depth of skin color. Vitiligo can occur if there is a lack of melanocytes or an obstacle to the production of melanin particles. Melanin particles can absorb ultraviolet rays and protect deep tissues from ultraviolet radiation.

2, spinous layer (spinous cell layer): located on the shallow surface of the basal layer, composed of 4-10 layers of polygonal cells, with many spinous protrusions. Push older cells in the basal layer up.

3. Granular layer: It is located on the shallow surface of the spinous layer and consists of 2-3 layers of spindle cells. The aged cells continue to be pushed into the granular layer. At this point, the cells have been filled with keratin-containing particles. As the keratin increases, the cells gradually become keratinized and die.

4. Transparent layer: It is located on the shallow side of the granular layer, and consists of 2-3 layers of flat cells without nucleus.

5. Cuticle (commonly known as dead skin): It is located in the shallowest layer of the epidermis and consists of several layers to dozens of layers of flat, non-nucleated keratinocytes. Strong resistance. The surface cells of the stratum corneum often fall off in small pieces, forming dander. The stratum corneum is the uppermost layer of the epidermis and consists of dead cells that have been completely keratinized. These tightly connected dead cells form the most important protective barrier. The stratum corneum will constantly accept those cells that have just died, and the outermost keratinocytes will continue to shed, so its thickness remains constant. In those frequently rubbed areas (palms, soles), the stratum corneum will thicken and form cocoons.

Causes of vitiligo vitiligo

When this process fails (for example, the reduction of copper (cu ++) or the increase of sulfhydryl groups (--- SH) in tyrosinase in melanocytes) leads to a decrease or even disappearance of tyrosinase, which in turn leads to a decrease and disappearance of melanin production. , Will form loss of pigment and produce white spots on the skin.

"Multiple Regeneration of Melanin in Traditional Chinese Medicine" records in ancient China that this disease was called vitiligo, and because of its onset of "indeterminate place", it has the characteristics of wind evil, and it is popular where and where it turns white, so it is named "Vitiligo".

Therefore, vitiligo is a kind of acquired primary depigmentation disease, which is caused by the decrease or loss of the function of the enzyme system of the melanin cells in the skin and hair follicles. It has been verified by the Chinese Medicine Research Center of China that it does not hurt, itchy, or Infection is rarely even inherited, but because of its beautiful appearance, it causes a great psychological burden and mental stress on patients.

Symptoms and classification of vitiligo

Patients with vitiligo generally do not have obvious itching symptoms, but only white spots or patches appear on the skin, and the skin tissue is normal. White spots will become more visible after exposure to the sun, including hands, feet, arms, legs, face and lips. The most common sites of disease include axillary and groin, around the mouth, eyes, nostrils, navel, and genitals. Vitiligo usually has three manifestations:

a, limited type: white spots are limited to one or more parts;

b. Segmental type (unilateral type): white spots along the dermal region of a cutaneous nerve segment are generally unilaterally distributed, more common in children, and more related to neurochemical factors; nearly half of segmental vitiligo occurs white Hair, usually involving hair and eyebrows. White hair means the destruction of melanocytes in the hair follicles, so segmental vitiligo responds poorly to drug complexing treatments;

c, pan-hair style: most people's white spots are located in different parts, usually symmetrical. Often due to the above two developments. In addition to white spots, many people's hair, eyelashes and beards also turn white. In rare cases, white spots can hit the retina and cause the eyes to lose color. Many people in daily life do not know much about the difference between vitiligo and leukoplakia. Maybe due to the wrong understanding of vitiligo and leukoplakia, it has caused some impact on their health.

White spot formation process

White spots can be congenital or acquired. Congenital leukoplakia may be caused by various reasons during embryonic development. Generally, whitish patches appear on the skin at birth or shortly after birth, such as non-pigmented nevi, anemia nevi, and non-pigmented pigment incontinence. The distribution of white spots is generally limited or has certain characteristics, and the color of white spots is not very white. With growth and development, these white spots neither fade nor significantly expand to the surroundings after stabilization. Acquired white spots have many causes. Because the skin is in direct contact with the external environment, the appearance of white spots on the skin is not only due to internal causes, but also due to external environmental factors such as sun exposure, chemicals, and fungal infections. There are many skin diseases that can cause hypopigmentation and depigmentation. Some inflammatory skin diseases can cause white spots on the skin. Before the appearance of these white spots, there are usually other inflammatory skin diseases, such as eczema and psoriasis, which destroy the melanocytes in the basal layer of the skin and cause skin pigmentation. Lost.

White spot

Common spots of white spot

White spots on lips

The range of leukoplakia can be limited or pan-type. Congenital leukoplakia can be localized, such as anemia nevus, non-pigmented nevus, and non-pigmented pigmented incontinence, etc., or it can be widespread throughout the body, such as albinism, mottled disease, etc. But after these white spots are fully formed, their range will not change significantly. Acquired leukoplakia varies according to its cause. For example, solar leukoplakia is distributed in the areas exposed to sunlight; pityriasis simplex is mostly located on the face; tinea versicolor is mostly located in areas where sebum overflows from the trunk; occupational leukoplakia is mostly located in areas exposed to chemicals. Some white spots can spread throughout the body, such as syphilitic white spots, senile white spots, etc., but these white spots are relatively the same size and will not fuse into a sheet.

Staging and judgment of vitiligo

1. Stable period

The white spots stop developing, the pigments on the edges deepen, and the realm is clear from the normal skin. It is often seen clinically that some patients do not develop for many years after the occurrence of leukoplakia, and the causative factors may only be transient and may not develop in the future (of course this is not absolute, but only In most cases).

2. Progress

White spots are still expanding or there are new white spots on other parts, and the boundary between white spots and normal skin is blurred. Causes of advanced white spot disease still exist, and the disease is still active. The treatment at this time should be based on the cause of the disease, such as hormones, immunomodulators, traditional Chinese medicine, physical therapy, etc. The focus is on quickly controlling the condition with effective drugs, and try not to let the white spots expand. Patients in advanced stage should not be exposed to excessive sun or use irritating drugs to avoid isomorphic reactions.

Countermeasures against white spot and white spot progression

After a period of treatment, advanced white spots may appear as follows:

(1) The treatment options are properly applied and the disease is controlled, and there are several possibilities:

After treatment, the white spot was completely cured; the white spot was reduced, but not all subsided; the white spot stopped developing, but did not shrink.

The former case is undoubtedly the best outcome. The latter two cases are generally considered to be relatively stable and can be treated with reference to the stable period.

(2) The disease has not been effectively controlled, and the disease continues to progress. This shows that the treatment is still wrong, and the cause should be analyzed and other treatment methods should be replaced.

What are the characteristics of white spots?

White spots caused by various reasons have different characteristics of the white spots themselves. First of all, according to the color of white spots, it can be divided into hypopigmented spots and decolorized spots. The color of hypopigmented spots is lighter than normal skin color, but does not become porcelain white. These leukoplakia are mainly found in some congenital leukoplakia and pityriasis simplex, tinea versicolor, and solar leukoplakia. Depigmented pigmentation refers to the appearance of white spots in pure white or porcelain white, which are mainly found in vitiligo and some white spots that appear after inflammatory skin diseases that have severe damage to melanocytes, such as white atrophy and lupus erythematosus. Secondly, the skin texture of different melasma also has its own characteristics. Some white spots have scales attached to the skin, such as pityriasis, tinea versicolor, etc .; some white spots have atrophy, such as pigment loss after ulcers, discoid lupus erythematosus, etc .; some white spots have dry skin, No sweat, no hair, such as leprosy white spots; In addition, the edges of different white spots also have their own characteristics. Some white spots have clear borders, and there may be deeper pigmentation around them, such as white atrophy, discoid lupus erythematosus, etc .; some white spots have blurred borders, and are generally hypopigmented spots.

Characteristics of white spots and vulva

Vulvar leukoplakia is a group of chronic diseases in which the female's vulvar skin undergoes degeneration and pigmentation. It is characterized by itching and burning of the vulva, skin pigmentation or whitening in the affected area, skin roughness, thickening or thinning, cleft palate and ulcers. .

Pathogenesis of vitiligo vitiligo

White spot neurochemical factor theory

Many clinical observations have shown that neuropsychological factors are closely related to the occurrence of vitiligo.

Spirit, nerve, and endocrine are a unified body. Psychological factors cause the body's stress and increase the levels of neuroendocrine hormones and neurotransmitters. However, mental factors focus on subjective aspects, while neuroendocrine is a measurable indicator and more objective. In addition, due to the internal connections of the nervous immune system, neurological factors may affect melanocytes through the immune system.

Vitiligo expert Qi Shujun pointed out that trauma or stress in life may play a role in the pathogenesis of vitiligo. Vitiligo onset or aggravation can often occur after a stressful mental event. As the saying goes, "sorrow, worry, and whiteness". It is estimated that about two-thirds of the cases have trauma, overwork, over-consideration, and anxiety after bedtime, sleeplessness, sleeplessness, and sleep disturbance during the onset or development of skin lesions. Tension and depression may not only induce vitiligo, but also enlarge the original skin lesions. Vitiligo is prone to friction and trauma. The experiment confirmed that after scratching the normal skin near the white spot and the distant part, the skin can be whitened, and the nerve fiber degeneration changes observed under the electron microscope, the degree seems to be related to the duration of the disease. Melanocytes originate from neural crests, and damage is often distributed along nerve segments. Vitiligo patients are often accompanied by autonomic dysfunction. Such as abnormal changes in sweating in the albino; associated with alopecia areata are often found; the rate of skin scratches is also higher.

White spot autoimmune theory

Patients or their relatives are sometimes associated with other autoimmune diseases, often with thyroid disease (hyperthyroidism or hypothyroidism, thyroid tumors), chronic adrenal insufficiency, malignant anemia, halo, alopecia areata, diabetes, rheumatoid arthritis, malignant melanin Tumors, bronchial asthma, atopic dermatitis, lupus erythematosus, atrophic gastritis, ulcerative colitis, uveitis, localized scleroderma, Sjogren's syndrome, etc. Some authors measured organ-specific autoantibodies in patients' serum and found that anti-thyroid, anti-gastric wall cells, and anti-adrenal tissue antibodies were elevated.

Professor Qi Shujun from China Research Center for Traditional Chinese Medicine has studied the pathological changes of vitiligo skin, and found that monocytes, especially lymphocytes, are active at the edge of the white spot, especially in the active phase. They invade the true epidermal junction and destroy the basement membrane into the epidermis. The absence of melanocytes and melanin indicates that the disease may be an autoimmune disease with delayed hypersensitivity. In addition, Langerhans cells in the basal layer of the diseased epidermis increased with electron microscopy, and there were lymphocytes around them, suggesting a local immune response. Such cells seem to be actively involved in the pathogenesis of vitiligo.

In recent years, the use of multiple melanin regenerative therapies in China in recent years to determine the presence of antibodies in the serum of patients with vitiligo vulgaris by indirect immunofluorescence, especially in patients with active periods and family history, the antibody positive rate is high. It is believed that this antibody is related to the occurrence of vitiligo, but this antibody The causal relationship with the disease itself remains to be further elucidated.

Some patients take corticosteroids internally or externally, especially for damage that is not distributed according to the dermatome (the pathogenesis may be autoimmunity), which indirectly proves the immune pathogenesis of the disease.

Leukocyte melanocytes destroy themselves

The basic lesion of vitiligo is partial or complete loss of function of the epidermal melanocytes.

Vitiligo expert Qi Shujun puts forward the theory of melanocyte destruction, and believes that the disease occurs predominantly in the exposed and deepened parts of the skin. Its epidermal melanocytes are hyperfunctional and promote their depletion and early decline. It may be due to the toxic black synthesis of the cells themselves. Caused by the accumulation of prodrugs. However, such substances could not be detected in leukoplakia.

Experimental studies have shown that certain chemicals can selectively destroy melanocytes and cause skin discoloration. The earliest report was hydroquinone monophenyl ether (a type of substituted phenols), which is often used as an antioxidant in rubber protective gloves. Workers can cause pigmentation on the skin of hands and upper limbs after contact.

Tyrosine and dopa are also dihydroxyphenol derivatives in the chemical structure, but under normal circumstances, the damaging effect of their oxidized intermediates may be eliminated by a protection mechanism. Once such protection mechanism is lacking, Melanocytes may be destroyed. Or individuals with genetic qualities have melanocytes with genetic and biochemical defects that are sensitive to damage. When a sufficient amount of toxic melanin precursor material is reached, it may cause destruction of melanocytes.

Relative lack of white spots

The production process of melanin is a complex biochemical process, while dopa is both the melanin and the precursor of adrenaline. Both are derived from tyrosine and are oxidized by tyrosinase. When the spirit is too nervous, a large amount of adrenaline is consumed. At this time, dopa mainly guides the synthesis of adrenaline. At this time, the synthesis of melanin will be affected, which seems to be a reasonable explanation for vitiligo caused by stress factors such as mental stress.

Many reports from the Armed Police Tianjin Corps Hospital in recent years and our experience suggest that the copper or ceruloplasmin (serum copper oxidase) values in the blood and skin of patients with vitiligo are lower than those in the normal control group. It is speculated that the result will inevitably lead to a decrease in tyrosinase activity, which will affect the metabolism of melanin. As for the reduction of copper and aeruginin values may be related to nutritional disorders, or copper's metabolic disorders and genetic defects.

Hereditary factors

Vitiligo expert Qi Shujun experts believe that genetic reasons have caused this sensitivity to vitiligo. Although not universal, families with more than one member who have vitiligo are indeed sufficient as a basis for genetic theory. Although no one at home has shown symptoms of vitiligo, there is still a genetic possibility.

But genes are inherited randomly from their parents, so it's just that at some point genes make one person more likely to have vitiligo. And even people who have unfortunately inherited the mutated gene need some external factors to induce white spots. So, although we haven't seen any one person getting the disease, genes may be passed down from generation to generation in a family.

Currently, researchers are focusing on studying the appearance of vitiligo genes, using computers to calculate the genome and human gene maps, but better discovering ways to treat genetic diseases and helping to treat and eliminate vitiligo.

The genetic probability of BB is only about 2%. Most of them are acquired, so don't worry too much

Interdependence

The various theories are not mutually exclusive, and may be causal. It is generally believed that its onset is manifested by various internal and external factors that stimulate immune function, nervous system and endocrine and metabolic functions in various aspects, leading to the inhibition of the enzyme system or the destruction of black cells or the obstacle to the production or melanin of melanin. To pigment loss. In addition, it is generally considered to be related to microcirculation disorders.

Incidence of vitiligo vitiligo

Vitiligo is one of the most common chronic skin diseases in the human body, and it occurs in people of all skin colors around the world. According to incomplete statistics, the prevalence in Shandong is 2.7%, Jiangsu 0.9-1.5%, Hubei 0.5-1%, and Shanghai 0.54%. Foreign countries such as 1.3-1.9%, Europe 0.38%, the United States 1%, India 4%. About 1-4% of the world's population has vitiligo. With the acceleration of people's pace of life and the intensification of environmental pollution, the number of patients has an increasing trend.

Vitiligo is an acquired acquired depigmentation disorder that usually develops before the age of 40, especially before the age of 20. It is reported that the youngest patient in the world develops the disease on the second day after birth, and it has developed under the age of two years. trend.

The incidence of vitiligo is not directly related to ethnicity.

Vitiligo common problems

Will vitiligo be transmitted?

Vitiligo is not contagious. If it is transmitted, patients in the world, including doctors and family members of patients who see vitiligo, will not be spared. There are many theories to explain the cause of vitiligo, but most scholars believe that patients with vitiligo belong to the susceptible population. Vitiligo may be inherited but never transmitted.

Vitiligo adolescent

Adolescents are at the developmental stage of long body and knowledge, and the neuroendocrine and immune system are relatively unstable, so they are susceptible to vitiligo. Some people calculated the age of onset of 1020 cases of vitiligo patients, 10-30 years old accounted for 62.65% of the total. The statistical result of 5230 cases of vitiligo in Beijing is 68.7% in 11-30 years old, of which 8.5% are under 5 years old; Luke's data is that 50% of cases occur within 20 years of age, and the average age of men is 26 , Female is 18 years old, but it is not uncommon for pediatric and elderly patients. This shows that vitiligo is prone to occur during adolescence.

Is vitiligo easy to recur?

One of the possible causes of vitiligo is immune dysfunction. Many antibodies can be detected in the blood of some patients, so some people have emphasized that vitiligo is an autoimmune disease. One of the characteristics of autoimmune disease is the slow and prolonged course of the disease, the disease is easy to repeat, and the tendency to relapse is obvious after healing. These phenomena are also common in vitiligo, so the recurrence phenomenon exists objectively in vitiligo.

White spots are prone to vitiligo

People of any region and race in the world can suffer from vitiligo. Generally speaking, there is not a significant difference in the incidence of vitiligo between occupations.

However, certain chemicals have a selective destructive effect on melanocytes, which can cause skin discoloration. For example, many chemical experimenters accidentally splashed with chemical reagents such as hydrogen peroxide and liquid nitrogen to discolor the skin and become permanent white spots. Therefore, people working in chemical plants, leather manufacturing, rubber factories and personnel exposed to chemical agents should do their own protection.

Leukoplakia easily induces vitiligo drugs

In clinical practice, there are many cases of discoloration of the skin caused by taking certain drugs, which is medically called drug-induced leukoplakia, which is a type of secondary vitiligo. Need to pay attention when you take medicine:

Artificial flavors, antihypertensive diuretics

Vitamin C drugs

Cystine, cysteine, dipropylpropanol, penicillamine

Thiourea, thiouracil, thyroxine, epinephrine, norepinephrine

These drugs may affect the anabolic metabolism of melanin due to individual differences. Therefore, they should be used with caution and self-observation.

Can white spot vitiligo bask in the sun

The skin color of the human body is constantly affected by factors such as the external environment and seasonal changes, the main one being sunlight. The color of the skin is deepened in summer, and the color of the outdoor workers is deeper. The direct solar energy promotes the production of melanin, deepens the skin color, and is beneficial to the treatment of vitiligo. However, vitiligo is also easily induced after excessive sunlight exposure: one is that the melanocytes function excessively after excessive exposure, prompting their consumption and early decline; the other is that the intermediates of melanin synthesis accumulate and damage melanocytes, thereby causing white spots.

So moderate sun exposure has a certain positive significance for the recovery of vitiligo, but excessive will promote the development of vitiligo.

Vitiligo in patients with vitiligo

(1). Hormones. Such as prednisone. Although this medicine is effective and easy to use, its side effects are great. Through long-term clinical practice, the disadvantages outweigh the advantages. Reason No matter which method is used for this kind of drugs, it can not eliminate the inhibitory effect on the body's adrenal cortex function and make the body dependent over time. The milder cause the body to have side effects such as acne, rosacea, glaucoma, skin streaks and atrophy, purpura, bacterial and fungal infections. In severe cases, the original adrenal gland secretion function is suppressed and atrophied, and the normal function of adrenal hormone secretion is lost. Once the drug is discontinued, the patient will have a severe rebound effect, making the condition more difficult to cure. Therefore, patients with vitiligo should use such drugs with caution, especially in patients with early onset and children.

(2). Antitumor drugs. The drugs used to control vitiligo in clinical practice are nitrogen mustard drugs. After long-term use of such drugs, it is easy to cause skin atrophy and aging.

(3). Copper preparation. Copper ion is an important prosthetic group of tyrosinase, which is closely related to tyrosinase activity, so it is useful to treat this disease with copper-containing drugs. However, clinical reports of copper sulfate intravenous injection in the treatment of this disease, there are cases of lethal reaction, it is not appropriate.

White spot termination treatment in winter

Many patients with vitiligo, especially some with a long course of disease and skin lesions located in non-exposed areas, after entering the winter, they think that the white spot will not develop in the winter and stop the treatment on their own. This is actually an illusion of them. In winter, due to less sunlight, the color of normal skin becomes lighter and the color difference between white spots is reduced. It is easy to be mistaken for the improvement of white spots. By the end of spring and early summer, the sunlight is stronger, and there are more opportunities for sunlight. As the color deepens, the color difference between it and white spots also increases. As the color of normal skin deepens, the color difference between it and white spots also increases. Coupled with less heat, it is easy to expose the white spots that were originally covered by clothes. This can easily be mistaken for the worsening of the condition. It can be seen that the practice of arbitrarily interrupting treatment in the winter is not appropriate and will delay treatment. The correct method is that the treatment is not affected by seasonal factors.

White spot stain or bleach

People with vitiligo should avoid using hair dyes or bleach. Some patients are very sensitive to these products and may cause further expansion of white spots, because they contain phenol derivatives, which can cause vitiligo to worsen.

Can vitiligo be cured?

To be exact, vitiligo does not yet have a global effective drug like isoniazid for the treatment of tuberculosis to eradicate vitiligo. No drug or treatment can guarantee a cure rate for every patient. But it does not mean that vitiligo cannot be cured, because of the complexity of the onset of vitiligo, so the special effects drugs that others have taken may not be effective if you take them, and vice versa. Generally speaking, if you take a drug for 5-6 months and have no effect (including pigment island, black circles, white spots are not so white, area shrinking or healing, etc.), you can consider trying other drugs.

Precautions for patients with vitiligo

White spots remain optimistic

Trauma or stress in life may play a role in the onset of vitiligo, and the onset or exacerbation of vitiligo often occurs after stressful events. Therefore, avoid trauma, excessive fatigue, and excessive thinking during the onset or development of skin lesions. Tension and depression may not only induce vitiligo, but also enlarge the original vitiligo. Patients with vitiligo should maintain an optimistic mood, relax, sleep well, and pay attention to rest.

White spots avoid contact with rubber gloves

Rubber protective gloves contain the antioxidant hydroquinone monophenyl ether, which selectively destroys melanocytes in the skin. Some workers wearing such rubber gloves have hypopigmented spots on the back of their hands and forearms, and even on their backs and lower limbs.

White spots reduce external stimuli

Patients with progressive vitiligo try to minimize mechanical irritation, stress, friction and trauma to the skin, such as tight belts, etc. can promote the appearance of white spots, and other forms of local stimulus, such as burns, sunburn, radiation, chemicals, Frostbite and infections can also promote the spread of white spots.

White spot attention to eating habits

Eat less fruits and vegetables rich in vitamin C, such as tomatoes, oranges, oranges, strawberries, orange juice, etc. Eat more tyrosine-rich foods such as yogurt, black rice, walnuts, black sesame, etc., pay attention to smoking less, drinking less, eating less Spicy, regular life.

. White spots . Avoid sun exposure

The lack of melanin in the white spots is difficult to resist the strong ultraviolet radiation in the sun, which will cause the white spots to appear red, swollen, itchy and even small blisters. So when you go out, you can choose to cover Bailin to protect the affected area while covering. You can also choose a sunscreen for protection, but it won't cover it.