Skin pigmentation

Introduction The color of the skin is determined by melanin (brown), carotene (yellow) in the epidermis, oxidized hemoglobin (red) in the dermal capillaries, and reduced hemoglobin (blue) in the vein, with melanin being the most important. In addition to ethnic and individual differences in the color of the skin, normal people often have physiological pigmentation in the exposed parts, wrinkles and rubbed parts; therefore, the change of skin color should be compared with the skin around the patient and the affected part. It should not be judged solely from the depth of color.

Cause

The mechanism of pigment abnormalities is complicated. Some pigmented skin diseases are caused by genetic factors; some are caused by secondary factors; others are not clear. This chapter has several explanations for its etiology classification.

1. Pigmentation based on the increase of melanin

1. Genetic factors

Freckle hereditary symmetry pigmentation disorder, racial black skin disease, coloration in skin disease, etc.

2, endocrine factors

Pregnancy melasma, Addison's disease, hyperthyroidism, acromegaly, Cushing's syndrome, acanthosis nigricans, etc.

3, physical machinery, chemical stimulation

Pigmentation caused by warming of sunburn, mechanical irritation, tar blackening, Rare melanosis, arsenic blackening, drug pigmentation, etc.

4, inflammation of pigmentation

Flat Moss, chronic eczema, dermatitis, skin amyloidosis, fixed drug eruption, lupus erythematosus, cancerous rash, acne pimples, pigmented measles, cosmetic dermatitis

5, systemic diseases

(1) Chronic infection: malaria, fever, schistosomiasis, tuberculosis, etc.

(2) neoplastic diseases: lymphoma, pain, ectopic ACTH syndrome, melanoma, etc.

(3) Nervous system diseases: diseases involving diencephalon and substantia nigra, hepatolenticular degeneration, ependymoma, schizophrenia, etc.

(4) connective tissue disease: systemic scleroderma dermatomyositis, systemic lupus erythematosus.

(5) Chronic liver and kidney disease, anemia can show pigmentation.

(6) Vitamin deficiency: Vitamin A lacks vitamin B; and folic acid deficiency, acid deficiency, vitamin C deficiency

Second, pigmentation based on the increase in the number of melanocytes

1. Genetic factors

Black skin disease, dermatological dysplasia, melanosis, perioral melanosis, etc.

2, the disease

Color-derived juvenile melanoma congenital color nevus nerve skin blackening disease, blue disease, animal skin, etc.

3. Congenital or unexplained reasons

Albright syndrome Mongolian plaque, Ota disease Ito, malignant freckle-like melanoma.

Third, endogenous non-melanin pigmentation

1, blood-borne pigmentation purple epilepsy red cell itself sensitive, progressive pigmented purple skin disease pigmented purple epilepsy moss-like skin disease, red group disease, limb cyanosis network reticular.

2, yellow pigmentation

Caroteneemia, brownish yellow disease, jaundice.

Fourth, exogenous pigmentation

1, metal pigmentation

Pigmentation spots caused by gold, silver, lead and mercury compounds

2, foreign matter pigmentation

Tattoos swelled with powdery granules.

an examination

Related inspection

Blood routine skin microscopy

First, medical history

The general project has the same detailed history as other chapters. Such as onset time, age, extent, development of pigment abnormalities; whether there are local symptoms or systemic symptoms; the incidence factors are primary or secondary; the effect of previous treatment; whether there is family history, genetic history and so on.

Second, physical examination

Check the color abnormalities to determine the color of the pigment abnormalities. If the yellow-brown plaque occurs on the face, it is found in chloasma; reddish brown is found in the erythema erythema of the face and neck; blue-brown is found in Ota disease; light black is seen in Riel melanosis; porcelain white is found in white epilepsy; There are fine sputum in the white pity. For example, the pigmented brown spots appearing on the trunk are found in coffee spots; the blue-brown is found in Mongolian spots; the light brown is found in measles such as pigmentation; and the pigmentation in exposed parts of the extremities is associated with contact allergy and light sensitivity. Pigment abnormalities with limited physical appearance above the skin surface are found in mites. Generalized pigmentation is seen in systemic diseases such as systemic scleroderma, dermatomyositis, and Addison's skin kala-azar. Generalized skin whitening is seen in albinism, and limited white spots are seen in white epilepsy.

Third, laboratory inspection

Histopathological examination is of great significance for the diagnosis of pigment abnormalities. In particular, pigmentation damage becomes darker and darker in the short term, and pathological examination is needed to prevent malignant transformation. Pigment abnormalities caused by systemic diseases can be checked in the laboratory for the primary disease.

Differential diagnosis

The differential diagnosis of skin pigmentation mainly includes:

First, the face-based pigmentation

1. Chloasma caused by endocrine and other factors for some reasons are unknown. Occurs in young women, after sun exposure, more common in the ankle, forehead upper lip and around the eyelids. It is slightly symmetrical for most of the flaky edges and has no symptoms.

2. Riel melanosis may be related to a certain contact or may be unknown due to light sensitivity or cause. Middle-aged women are more common, and the relationship with sun exposure is not obvious. The forehead, collar, ear circumference and neck side are the central color of the heavy face, which is flaky light brown or light black spot. The border is not clear and the surface is mild. Keratinized or thin scales, no symptoms.

3. The cause of tar blackening is long-term exposure to bituminous petroleum and petroleum products. There are more adult males, and the sun-related symptoms are diffuse pale brown or dark brown spots on the face and exposed parts. May be associated with acne-like lesions.

4. Freckle genetic factors are often aggravated after childhood sun exposure. It manifests as a facial needle to a large yellowish brown or dark brown spot with no symptoms.

5. Ota thin is also known as the hereditary or congenital factors in the eye, and it is a disease in childhood or youth. It has nothing to do with sun exposure, the upper and lower eyelids and ankles, and the edges are clear and pale blue or blue and black. Unilateral, some ipsilateral sclera blue stain, no symptoms

6. Perioral sunspot disease, also known as the genetic factors of pigmented polyposis syndrome, has not been associated with sun exposure in the lip, especially in the lower lip, oral cavity film has brown and black spots. Can also occur in the face of the hands, feet, can be accompanied by intestinal polyp bed can cause abdominal pain diarrhea, accompanied by ulcers can have bleeding, a small number of patients can be cancerous can also be associated with alopecia areata, nail dystrophy, rod-shaped finger polyps Wait.

7. The genetic factors of pigmentation in the skin disease system have been onset since childhood and increased after sun exposure. Brown spots often appear on the exposed parts of the hands or feet of the face, with telangiectasia and atrophy, verrucous hyperplasia and hyperkeratotic rash can occur cancer.

8. Cosmetic dermatitis refers to pigmentation caused by facial cosmetic dermatitis. A pale brown, reddish-brown or light black spot on the edge of the face or a diffuse sheet or mesh. Some patients have or have had dermatitis and itching.

9. Benign juvenile melanoma, also known as spindle cell disease, is a benign tumor derived from melanocytes. It is common in children who are seen in young people. It is manifested that the buccal ear can also be seen in the limbs and the trunk is a solid nodule. Start to grow quickly but not more than 2cm in diameter, the surface is reddish brown pigmentation, adult development into Pinet

10. Fixed drug eruption is more common around the lips, oval pigmentation spots can also be seen in the genitals and other parts.

11. Contact dermatitis is often associated with contact with sensitizers on the face or other contact sites. Pigmentation spots are formed after repeated dermatitis.

12. Drug-induced pigmentation Large doses of chloropropionic acid appear on the face or exposed areas with blue-gray pigmentation spots. Long-term use of dimethylamine can cause blue-black, blue-gray or facial acne lesions or forearm calves and exposed areas. The brown pigmentation leukosin pigmentation system produces blue-gray spots on the face and sunlit parts after long-term use. Similar to silver stains.

13. Accidental Dust Deficiency Causes persistent pigmentation of the skin due to explosion or occupational damage to the skin causing some colored powdery substances to enter the skin. Common in the face and exposed parts.

14. Malignant freckle-like skinny, also known as black-denatured freckles, is unknown in women over 40 years of age. It begins to develop brown spots on the face or exposed parts. After many years, some patients can become melanoma.

Second, the pigmentation of the trunk and limbs

1. Hereditary symmetry dysepsia The genetic factors are young, puberty is obvious, and the lifelong performance is the symmetry of the hands and feet. Most of the pigmentation spots of the beans are accompanied by pigmentation spots and no symptoms.

2. Acromegaly is dominant in infants or in childhood. It is characterized by diffuse pigmentation of the dorsal skin of the (toe) and pigmentation on the flexion side of the limbs.

3. Black skin disease dominant inheritance at birth or in infants, skin pigmentation increases, diffuse distribution, post-pigment gradually deepens to the face and wrinkles, the pigment is the heaviest, dark hair, may be accompanied by multiple black sputum.

4. After the pigmentation occurs, it can occur in the whole body or in the adolescence. There are several to dozens, and most of them are benign and very few borders.

5. Blue fatigue is a single or multiple incidence of childhood. Occurs in the upper limbs, the trunk or face is blue nodules, soft or solid, with clear boundaries

6. Pigmented giant skin is also known as the skin after the birth of the skin, with age. It occurs on the back of the torso with dark black spots and hair on the spots. Skin thickening surfaces have nodules of varying sizes, which can form skin-like wrinkles due to thickening.

7. Coffee spots are more common in young torso, with light brown round or oval spots, no symptoms.

8. Mongolian plaque is a benign blue plaque lesion. I have a good waist and abdomen, and naturally fade after a few years.

9. Ito is similar to the pigmentation of Ota disease in the shoulder and upper arm, also known as the shoulder triangle deltoid cyan.

10. Malignant melanoma is often blue-black in the middle and old age, often occurring in the face, neck, sole and underarm. Black patches or small nodules. Gradually increase, there may be ulceration and so on. The disease is highly malignant, once diagnosed and early surgical resection

11. Black sphincter disease occurs in the genital anal area of the wrinkle area and the elbow and knee area. It is a brownish-brown hypertrophic pigmentation spot. The incidence of children is mostly benign, and adult patients may be accompanied by malignant tumors.

12. Pigmented urticaria is caused by juvenile and adult type of mast cell proliferation. Mostly from childhood, the adult rash can also be caused by the trunk, the first is the trunk. The winds that do not retreat from the extremities gradually become yellow-brown or gray-brown spots; they may also be rashes such as maculopapular rash, papules, and nodular water cancer. The wheal may appear on the spot after being scratched or scratched. Histopathological examination showed a large amount of mast cell infiltration in the dermis

13. Addison's disease is chronic adrenal dysfunction and diffuse pigmentation of the whole body skin. Bronze, brownish black with nipple thick halo, genital area, face and wrinkles

14. Post-inflammatory hyperpigmentation is a secondary temporary pigmentation such as chronic eczema, dermatitis, seborrheic dermatitis and other skin diseases, which can leave pigmentation spots. It is the result of a combination of chronic inflammatory stimuli, mechanical stimuli, or topical irritant drugs.

Third, non-melanin pigment abnormalities

1. Blood-derived pigmentation such as purpura causes red blood cell plasma to exude skin and blood vessels, causing changes in skin color. Due to the depth of the small parts of the purple epilepsy and the length of the disease, it can be expressed in red, purple blue, brown or brownish yellow.

2. Caroteneemia is caused by overeating carrots and oranges, so that normal skin appears yellow, but the color of the sclera does not change, and should be differentiated from astragalus.

3. Brown yellow disease, also known as black urine genetic factors are black urate oxidase deficiency. In children, only urine color changes occur. Skin pigmentation spots occur after 30-40 years of age. The face, underarms, and genital area are light gray, light blue, light brown, or dark brown with bone and joint diseases.

4. Tattoos vary in color depending on the pigment entering the skin. Such as black, cyan blue or red. It is artificially created with a variety of different patterns.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.