Necrobiosis lipoidica is a chronic skin disease caused by the deposition of fats in skin areas with degenerative and necrobiotic changes. Characteristic is the appearance of nodules in the skin, the mergers of which form dense plaques with a shiny surface. Accurate diagnosis of the disease is carried out according to histological examination. An important point is to determine the level of sugar in the blood. Treatment is carried out with glucocorticoid ointments, antioxidants, drugs to improve microcirculation, laser therapy. In diabetics, the main therapy consists in taking antidiabetic drugs and injecting insulin.
Necrobiosis lipoidica refers to localized skin lipoidosis. 75% of cases of the disease are observed in patients with diabetes mellitus. People aged 20 to 40 are most often ill, children and the elderly are less likely. Women get sick about 3 times more often than men. Necrobiosis lipoidica is a fairly rare disease. About 4% of diabetics suffer from it.
The occurrence of necrobiosis lipoidica is associated with metabolic disorders occurring in the body, in particular carbohydrate and fat metabolism. An important role is also played by a violation of microcirculation of individual skin areas, which is observed in patients with diabetes mellitus or after injuries (bruises, bites, wounds, etc.), a violation of microcirculation leads to degenerative changes in skin cells and their necrobiosis — a change in intracellular metabolism. As a result, there is a fatty degeneration of cells.
Lipoid necrobiosis begins with the appearance of small pinkish-red nodules of a rounded shape on the skin. On the periphery, the nodules are surrounded by a violet-blue border, and in the center they have a yellowish-gray depression. Along with these elements, small subcutaneous nodules of red color may form, representing cystic capillary extensions.
Nodules of necrobiosis lipoidica are prone to peripheral growth and eventually merge into flat dense plaques, the smooth surface of which has a specific shine. The central part of the plaque resembles the manifestations of scleroderma, the skin above it is atrophic, has a smoothed pattern and seems to be covered with a translucent film. Along the periphery of the plaque there is a narrow slightly towering roller of brown or bluish-red color.
Skin lesions in necrobiosis lipoidica are not isolated. The symmetrical arrangement of plaques on the right and left is characteristic. The skin of the lower extremities is most often affected. The typical localization of the process in necrobiosis lipoidica is the lower leg (in 80% of cases). There are skin lesions of the thighs, trunk, forearms and scalp.
In the uncomplicated course of necrobiosis lipoidica, skin changes are not accompanied by any subjective sensations. Tingling, burning and soreness appear if superficial defects and ulceration form on the skin. Severe complicated course of the disease is observed in patients with diabetes mellitus. A direct dependence of the intensity of the manifestations of necrobiosis lipoidica on the blood sugar level was observed. With its increase, there is an increase in the area of skin lesions and the occurrence of poorly healing ulcers. A decrease in blood sugar leads to partial or complete resorption of plaques and a decrease in the area of the lesion.
A specific form of necrobiosis lipoidica is chronic progressive granulomatosis of Mischer. It is characterized by the formation of disc-shaped plaques of large size and wooden density on the skin.
Lipoid necrobiosis proceeds for a long time. Spontaneous regression of symptoms of this disease was observed only in exceptional cases. Often, after the symptoms disappear during treatment, the disease develops again.
A typical clinical picture often makes it possible to diagnose necrobiosis lipoidica, especially when it occurs in a patient with diabetes mellitus. The diagnosis is confirmed by the data of histological examination of the sample obtained by biopsy of the affected area of the skin. Characteristic is the detection of foci of necrobiosis in the dermis, as well as fibrosis and proliferation of the endothelium of the blood vessels of the dermis. The epidermis is often unchanged. In the course of histological examination, specific staining with Sudan is used to detect lipids, while numerous extracellular accumulations of fat grains are detected by the rusty-brown color.
In the diagnosis of necrobiosis lipoidica, it is mandatory to determine blood sugar, if necessary, to conduct a glucose-tolerant test. Differential diagnosis of necrobiosis lipoidica is carried out with scleroderma, tubercular syphilis, annular granuloma, sarcoidosis, papulonecrotic vasculitis, indurative erythema Bazin, nodular erythema.
In patients with diabetes mellitus, the basis for the treatment of necrobiosis lipoidica is the therapy of diabetes mellitus and normalization of blood sugar levels. For this purpose, treatment with an endocrinologist with the selection of optimal doses of insulin or antidiabetic drugs (glibenclamide, gliclazide, tolbutamide, metformin, etc.) is recommended. Additionally, glucocorticoid ointments and intraocular administration of glucocorticoids, antioxidants (vitamin E preparations, lipoic acid) and means that improve microcirculation (pentoxifylline, dipyridomol, xanthinol nicotinate) are used.
Bucca rays (ultra-soft X-ray radiation) and X-ray irradiation are effective against foci of necrobiosis lipoidica. One of the methods of therapy is combined laser therapy, combining percutaneous laser irradiation of blood and subsequent pulsed laser irradiation of lesions. In some cases, surgical excision of pathological foci is indicated.