Lipoid necrobiosis: causes, symptoms, diagnosis, treatment

Necrobiosis lipoid (synonyms: lipoid diabetic necrobiosis, atrophic spotted lipoid dermatitis) occurs in 4% of patients with diabetes mellitus.

The causes and pathogenesis of lipoid necrobiosis have not been fully established to date. It is believed that the basis of the disease are microcirculatory disorders, in the emergence of which great importance is circulating in the blood of toxins, immune complexes, neuro-endocrine disorders. Lipoid necrobiosis is often found in diabetic patients, as diabetic microangiopathy is accompanied by disorganization of connective tissue and the deposition of glycoprotein on the walls of blood vessels. As a result, lipids are deposited in the lesion. Trigger factors can be various injuries of the skin (bruises, scratches, insect bites, etc.). There are reports of the role of lipid peroxidation in the pathogenesis of lipoid necrobiosis.

Symptoms of lipoid necrobiosis. Clinically, there are usually scleroderm-like plaques most often located along the anterior surface of the shins with pronounced central scarring atrophy and telangiectasias, sometimes with ulceration; rarely superficial scattered foci with little or no condensation and hardly noticeable atrophy, surrounded by a stagnant erythema: scattered or grouped nodular rashes with the formation of foci similar to annular granuloma. There are rare variants: papulonecroctic, sarcoid, resembling persistent erect erythema, panniculitis, erythema nodosum, xanthomas, lupus erythematosus, malignant atrophic papulosis of Degos.

Lipoid necrobiosis can occur at any age. Women are more often ill. In most patients, lesions are located on the lower extremities (shins, feet), but can also occur in other parts of the skin. The disease begins with the appearance of spotted or nodular elements, the color of which varies from yellowish-reddish, reddish-brown to lilac. Elements have clear boundaries, a smooth surface, a round or irregular shape, a small infiltration. Sometimes on the surface there is a slight peeling. Over time, peripheral growth and fusion of these elements are noted, resulting in plaques of round or oval shape, polycyclic outlines, consisting of the peripheral and central parts. The peripheral part has a reddish-brown or red-cyanotic hue and slightly rises above the level of the surrounding skin. The central part of a yellowish-brown color or ivory with a smooth surface somewhat sinks. The focal lesion sometimes resembles plaque scleroderma. Very often, numerous telangiectasias are noted on the surface of lesions, as a result of trauma - erosion, ulcers. Subjective sensations are absent.

In addition to the above described classical form, there is scleroderm-like, superficial plaque, such as annular granuloma of the form of lipoid necrobiosis.

Scleroderm-like form is most common. It is characterized by the presence on the skin of single, rarely - multiple rounded plaques of irregular contours, with a shiny surface. Due to pronounced infiltration during palpation of lesions, a scleroderm-like densification is determined. Skin over the foci in the folds is not going. The process often ends with the formation of rubnevitnoy atrophy. In some patients (especially with diabetes) on the surface of the foci appear superficial ulcers of irregular contours with soft, slightly eroded, edges. Ulcers have serous-hemorrhagic discharge, when drying, dark brown crusts are formed. Subjective sensations are usually absent, only with ulceration appears soreness.

Lipoid necrobiosis of the type of annular granuloma is often localized to the hands, wrist joints, rarely - on the face, trunk. Foci of lesion have an annular shape, along the periphery are surrounded by a cyanotic-red roller or pinkish-cyanotic color with a yellowish tinge. In the center of the hearth, the skin is slightly atrophic or unchanged. The clinical picture resembles an annular granuloma.

The surface-plaque form is characterized by the formation of multiple plaques of rounded or irregular scalloped contours ranging in size from a small coin to the palm of an adult and more pinkish-yellow in color, bordered by a purple-reddish or sirenovato-pink rim 2-10 cm wide. There is no consolidation at the base of the plaques, perhaps small-plate scaling on their surface.

Histopathology. Hyperkeratosis is noted in the epidermis, occasionally atrophy and vacuolar degeneration of the basal layer. In the dermis, there are changes in the vessels of a productive nature, necrobiosis of collagen, the deposition of lipoids, an infiltrate consisting of histiocytes, lymphocytes, fibroblasts, epithelioid and giant cells of foreign bodies. In the walls of blood vessels there are characteristic signs of diabetic microahipopathy (fibrosis and hyalinosis of the walls, proliferation of the endothelium and thrombosis of small vessels). Depending on the histological picture, a granulomatous or necrobiotic type of tissue reaction is distinguished. When painting disclose lipoid deposits.

Pathomorphology. In the dermis, two types of changes are possible: necrobiotic and granulomatous. With a necrobiotic type, mainly in the deep sections of the dermis, there are various sizes, indistinctly limited foci of necrobiosis of collagen fibers. Fibers amorphous, basophilic, a small amount of "nuclear dust" is determined.

On the periphery of foci of necrobiosis. And also in the thickness of the entire dermis and even in the subcutaneous fat layer, there are perivascular and focal infiltrates from lymphoid cells, histiocytes, fibroblasts, sometimes with the presence of groups of epithelioid cells. Giant multinuclear cells such as foreign bodies are often found. Significant changes in the vessels are noted: proliferation of the endothelium, thickening of the walls, narrowing of the lumens. When the color of Sudan red and scarlet in the foci of necrobiosis, often (but not always) reveal a large amount of fat that is painted in a rusty-brown color, unlike the orange-red color of neutral fat of the subcutaneous fat layer. With granulomatous type of changes, granulomatous foci consisting of histiocytes, epiglioid and giant cells are seen. Foci of necrobiosis and fat deposits are less pronounced than in the necrobiotic type, and sometimes absent. Some authors consider changes of this nature as manifestations of a peculiar disease - the progressive chronic disk-like granulomatosis of Mischer-Leder (granulomatosis discifoimis chronica progressiva Miescher-Leder). The epidermis in lipid necrobiosis is not altered or somewhat atrophic, in pits of ulceration destroyed. In old foci, sclerosis is expressed, small vessels in these areas are sclerosed, their lumens are closed, perivascular fibrosis is noted, very rarely - a giant cell reaction.

Histogenesis. The main role in the development of the disease is given to microangiopathies of various origins, primarily diabetic, with the subsequent deposition of lipids. With the help of the fluorescence reaction, the deposition of the IgM and C3 complement components in the walls of the vessels and in the zone of the dermo-epidermal border in the lesions is detected. In the development of microangiopathies, hormonal disorders, activation of free radical lipid oxidation, an increase in serum lipid level patients are important. Immunomorphological study with antisera to antigen S-100 showed a reduction in the number of nerve endings in plaques, which is associated with a decrease in skin sensitivity in these zones.

Treatment of lipoid necrobiosis. It is necessary to identify and treat diabetes. Recommended diet poor in carbohydrates and fats, vascular drugs (nicotinic acid, trental, etc.), antioxidants (lipoic acid, alpha-tocopherol), intralesional injections of corticosteroids and insulin. External apply long-term corticosteroid ointments, physiotherapy (ultrasound, laser therapy).

[1], [2], [3], [4], [5], [6], [7]