Skin melanosis is an excessive deposition of melanin pigment in the epidermis. This substance is produced by special cells (melanocytes) and is designed to protect skin cells from the sun's rays. In fair-skinned people, this 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 skin color.
Causes of disease
Melanosis of the skin can be caused by various reasons. A change in the color of the epidermis can provoke the following factors:
- pathology of the endocrine glands (pituitary gland, adrenal glands, ovaries, thyroid gland);
- infectious diseases (syphilis, dysentery, tuberculosis, malaria);
- poisoning with arsenic, carbon compounds and toxicresin;
- advanced forms of head lice;
- liver disease;
- blood diseases (porphyria);
- pathology of connective tissue (collagenosis);
- medication (sulfonamides, tetracycline antibiotics, photosensitizing drugs).
In addition to pathological causes, discoloration of the skin can occur as a result of 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
There are localized and generalized types of melanosis of the skin. What does this mean? In the first case, pigmented areas appear on the epidermis. With generalized melanosis, the color of the entire skin integument changes.
Generalized melanosis of the skin is most often noted in Addison's disease, pituitary pathologies, diabetes, collagenosis, 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 Civatta. This pathology occurs in women of childbearing age. The disease is associated with a functional failure of the ovaries or adrenal glands.
- Riehl's melanosis. The cause of this disease is not exactly clear. It is believed to be due to contact with hydrocarbons.
- Toxic melasma of Hoffmann-Habermann. This disease occurs only inmen. It is caused by hydrocarbon poisoning. People with excessive sweating usually suffer from this disease.
With the above diseases, there are pigmented spots on the face and neck of the patient. At the same time, the rest of the skin does not change its 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. Observed in case of insufficiency of kidney function.
- Endocrine. Occurs with diseases of the adrenal glands, pituitary gland, ovaries or thyroid gland.
- Toxic. It is caused by arsenic and hydrocarbon poisoning.
- Liver. 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 also 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. They usually appear on the face. The reasons for their appearance have not been established. Supposed. that they are formed due to hormonal disorders.
- Lentigo. These are small yellow or brown spots on the face. They aregood quality formations. However, with injury or excessive exposure to the sun, malignant degeneration of cells is possible.
- Melanosis Becker. 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, as it does not degenerate into cancer.
- Dubrey's melanosis. This formation occurs in people over 50 years of age. It looks like a raised brown spot 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.
Symptomatics
Symptoms of pathology depend on its form and cause. If the entire skin of the patient turns bronze or yellowish, 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. With toxic melasma, these areas of the body are evenly colored grayish-yellow. 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 malignant degeneration of rashes. In this case, only the underlying disease poses a he alth hazard. If melanosis is of a primary nature, and a mole or spot has appeared on the skin, then it should be urgentlysee 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, change in shape and color, the appearance of ulcers and bleeding. Exposure to ultraviolet rays and trauma to the formation can provoke malignancy. It should be remembered that moles covered with hair are not dangerous.
Diagnosis
Melanosis is treated by a dermatologist. However, if the change in skin color is caused by other diseases, then consultation of an endocrinologist, therapist, infectious disease specialist and other specialists is necessary.
The following examinations are ordered:
- The patient's skin is examined with a special black light lamp (Wood's lamp).
- Biopsy of the affected areas of the skin. Particles of the epidermis are taken for histological examination.
- They do a dermoscopy. This is an absolutely painless examination 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 the mole in detail. If there is doubt about the good quality of the formation, then a biopsy is prescribed. Histological examination distinguishes melanoma tumor from melanosis of the skin. A micropreparation of the epidermis with a nevus (mole) can be seen in the photo above, black-brown granules are accumulations of melanin.
Treatment
Ifmelanosis is secondary, it is necessary to treat the underlying disease. In this case, the skin color is normalized after the end of the course of therapy. In primary melanosis of the skin, treatment is carried out both conservatively and surgically. The following drugs are prescribed:
- vitamins A, E, ascorbic and nicotinic acid;
- corticosteroid hormones;
- antihistamines.
Also use topical preparations:
- hydrogen peroxide;
- creams and ointments with vitamin A;
- citric acid solution.
Today, there are cosmetic procedures that help whiten the skin and eliminate spots. However, before using such methods, it is necessary to undergo diagnostics and make sure that 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 to 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 whitened.
- Laser resurfacing. Under the influence of a laser beam, the problematic area of \u200b\u200bthe skin evaporates.
Surgical treatment is indicated in some cases. This is necessary when the mole is prone to malignancy. The nevus is removed under local anesthesia, and the resulting material is sent tohistological examination. If the operation is not possible, then the mole is irradiated.
Prevention
Prevention of secondary forms of melanosis is the timely treatment of diseases that lead to skin discoloration. Great care must also be taken when working with arsenic and hydrocarbon compounds. Prevention of primary forms of melanosis has not been developed, since the causes of their occurrence are not known. When moles and spots appear on the skin, it is necessary to consult a dermatologist as soon as possible. Such rashes can be dangerous. In these cases, it is necessary to avoid exposure to sunlight and trauma to moles and spots.
