Skin melanosis is the excessive deposition of the pigment melanin in the epidermis. This substance is produced by special cells (melanocytes) and is intended to protect skin cells from the sun. In fair-skinned people, such pigment is produced in smaller quantities than in dark-skinned people. Normally, melanin is activated only under the influence of ultraviolet radiation. In this case, a tan appears on the skin. If this pigment is deposited in large quantities, then a disease occurs - melanosis. It is accompanied by a change in the color of the skin.
Causes of the disease
Skin melanosis can be caused by various reasons. Changing the color of the epidermis can trigger the following factors:
- pathology of the endocrine glands (pituitary, adrenal gland, ovary, thyroid gland);
- infectious diseases (syphilis, dysentery, tuberculosis, malaria);
- poisoning with arsenic, carbon compounds and toxic resins;
- advanced forms of lice;
- liver disease
- blood diseases (porphyria);
- pathology of connective tissue (collagenosis);
- taking medications (sulfonamides, tetracycline antibiotics, photosensitizing drugs).
In addition to pathological reasons, a discoloration of the skin can occur due to malnutrition and metabolic disorders in the epidermis. There is also a hereditary form of melanosis, in which the disease is transmitted from parents to children.
Localized and generalized forms
A localized and generalized type of skin melanosis is distinguished. What does this mean? In the first case, pigmented areas appear on the epidermis. With generalized melanosis, the color of the entire skin changes.
Most often, generalized skin melanosis is observed in Addison's disease, pituitary pathologies, diabetes, collagenoses, arsenic poisoning, and also with an excess of porphyrins in the blood. In this case, the entire skin of a person acquires a bronze color.
Localized melanosis is a symptom of the following diseases:
- Poikiloderma Sivatta. This pathology occurs in women of childbearing age. The disease is associated with a functional malfunction in the ovaries or adrenal glands.
- Melanosis of Riel. The cause of this disease is not exactly clear. It is assumed that it occurs due to contact with hydrocarbons.
- Toxic melasma of Hoffmann-Gaberman. This disease occurs only in men. It is caused by poisoning with hydrocarbon substances. Usually people with excessive sweating suffer from this disease.
With the above diseases, pigmented spots on the face and neck of the patient are noted. In this case, the remaining areas of the skin do not change their color.
Varieties of pathology by origin
There is also a classification of pathology depending on its origin. The following types of skin melanosis are distinguished:
- Uremic. It is observed with renal failure.
- Endocrine. It occurs with diseases of the adrenal gland, pituitary gland, ovary or thyroid gland.
- Toxic. Its cause is arsenic and hydrocarbon poisoning.
- Hepatic. This form of melanosis is associated with cirrhosis, hepatitis and other liver diseases.
- Cachectic. It is noted with severe exhaustion, most often with pulmonary tuberculosis.
These forms of pathology are secondary. Melanosis in these cases is only one of the symptoms of other diseases. However, there are primary forms of skin melanosis. Some of them are dangerous, as they are prone to malignant degeneration. These types of pathology include the following diseases:
- Chloasma. These are large brown spots on the epidermis. Usually they occur on the face. The reasons for their appearance have not been established. It is assumed. that they are formed due to hormonal disorders.
- Lentigo. These are small yellow or brown spots on the face. They are benign formations. However, with trauma or excessive exposure to the sun, malignant degeneration of cells is possible.
- Becker melanosis. This disease affects mainly young men. A mole appears on the skin, which is then covered with a thick hairline. This formation is not dangerous, since it does not degenerate into cancer.
- Melanosis of Dubei. This formation occurs in people over 50 years old. It looks like a convex brown stain that looks like a mole. This disease is a precancerous condition and requires immediate treatment. The neoplasm consists of atypical melanocytes, which easily degenerate into malignant cells.
Symptomatology
Symptoms of a pathology depend on its form and cause. If the entire skin of the patient is painted in bronze or yellowish color, then this indicates a generalized form of skin melanosis. Photos of the manifestations of the disease can be seen below.
If melanosis occurs in a localized form, then rashes are noted only on the face and neck. In toxic melasma, these parts of the body are evenly painted in a grayish-yellow color. Rashes in the form of age spots, moles and freckles are most often primary.
Complications
If melanosis is secondary, then one should not be afraid of the malignant degeneration of rashes. In this case, only the underlying disease is a health hazard. If melanosis is of a primary nature, and a mole or spot appears on the skin, then you should immediately consult a doctor. Some of these formations are prone to malignant degeneration and can develop into skin cancer - melanoma. Malignancy (malignancy) of a mole is evidenced by its accelerated growth, a change in shape and color, the appearance of ulcers and bleeding. Malignization can provoke exposure to ultraviolet rays and trauma to the formation. It should be remembered that moles covered with hair are not dangerous.
Diagnostics
A dermatologist is involved in the treatment of melanosis. However, if the discoloration of the skin is caused by other diseases, then consultation with an endocrinologist, therapist, infectious disease specialist and other specialists is necessary.
The following examinations are prescribed:
- The skin of the patient is examined using a special lamp of black light (Wood lamp).
- A biopsy of the affected areas of the skin is performed. Particles of the epidermis are taken for histological examination.
- Do a dermoscopy. This is an absolutely painless study that does not require excision of the affected areas. Neoplasms on the epidermis are examined under a special device - a dermatoscope.
Dermoscopy allows you to examine a mole in detail. If there is doubt about the good quality of education, then a biopsy is prescribed. Histological examination allows to distinguish a tumor from melanoma from skin melanosis. A microdrug of the epidermis with nevus (mole) can be seen in the photo above, black-brown granules are accumulations of melanin.
Treatment
If melanosis is secondary, it is necessary to treat the underlying disease. In this case, the skin color normalizes after the course of therapy. With primary skin melanosis, treatment is carried out both by conservative and surgical methods. The following drugs are prescribed:
- vitamins A, E, ascorbic and nicotinic acid;
- corticosteroid hormones;
- antihistamines.
Also use drugs for external use:
- hydrogen peroxide;
- creams and ointments with vitamin A;
- citric acid solution.
Nowadays, there are cosmetic procedures that help whiten the skin and eliminate stains. However, before using such methods, it is necessary to undergo a diagnosis and make sure the neoplasm is benign. The following procedures will help get rid of spots on the skin:
- Chemical peeling. A special composition is applied to the face, which helps exfoliate the upper layer of the epidermis.
- Phototherapy. The skin is exposed to pulsed light. This causes a change in the structure of melanin. As a result, the epidermis is bleached.
- Laser resurfacing. Under the influence of a laser beam, evaporation of the problem area of the skin occurs.
In some cases, surgical treatment is indicated. This is necessary when the mole is prone to malignancy. Nevus is removed under local anesthesia, and the resulting material is sent for histological examination. If the operation is impossible, then mole irradiation is used.
Prevention
Prevention of secondary forms of melanosis is the timely treatment of diseases that lead to discoloration of the skin. Great care should also be taken when handling arsenic and hydrocarbon compounds. Prevention of primary forms of melanosis is not developed, since the causes of their occurrence are not known. If moles and spots appear on the skin, consult a dermatologist as soon as possible. Such rashes can be dangerous. In these cases, exposure to sunlight and trauma to moles and spots should be avoided.