Flabby skin: causes, symptoms, diagnosis, treatment

Sluggish skin (syn: dermatochalasis, generalized elastolysis) is a heterogeneous group of generalized connective tissue diseases with general clinical and histological skin changes. Distinguish between hereditary and acquired forms. Among the hereditary lesions, autosomal dominant and autosomal recessive types are distinguished. A sex-linked type of disease is described, in which symptoms of flaccid skin are combined with hyperelasticity. The autosomal dominant type of the disease has a benign course, the involvement of the connective tissue affects mainly the skin, while the recessive type is characterized by a generalized lesion of the connective tissue.

The causes and pathogenesis of flaccid skin have not been adequately studied. The possibility of disruption of collagen synthesis with intracellular accumulation of procollagen, a decrease in the production of tropoplastin, an increase in elastase activity with a decrease in the function of its inhibitors, a deficiency of lysinoxidase (with X-linked form), a decrease in copper concentration, and the role of autoimmune reactions are indicated. Important in the development of the acquired form of the disease are infectious processes, immune disorders.

The clinical picture of skin lesion is the same for all types of disease. Skin is mobile, it stretches easily, after stretching ceases very slowly it returns to its original position, under the weight of its own mass, it hangs, forming folds and wrinkles, especially pronounced on the face in the eyelids (blepharohalasis), nasolabial folds, on the neck, chest, abdomen, back , which makes the sick of the young age look prematurely older. Characterized by a hooked nose with turned nostrils and a long upper lip, saggy ears, a low hoarse voice, which is due to the stretching of the vocal cords.

In the autosomal recessive type of inheritance, two clinical forms of flaccid skin are distinguished. The first is characterized by a generalized disorder of the structure of the elastic fibers, manifested as emphysema of the lungs, with progressive pulmonary insufficiency, anomalies in the structure of the cardiovascular system with damage to the elastic membrane of arterial vessels, including the pulmonary artery and aorta, diverticula in the gastrointestinal tract and genitourinary organs. Such defects can be the cause of death at an early age. The second form is manifested by developmental defects: pre- and postnatal growth disorders, congenital hip dislocation, various bone defects and an uninhibited anterior fontanel.

X-linked version of flaccid skin is characterized by the presence of bony projections on both sides of the large occipital opening, diverticula of the bladder. Patients usually have a hooked nose and an elongated upper lip. Fibroblasts of patients and heterozygous carriers in culture contain a lot of copper, a defect in its metabolism and associated decrease in lysine oxidase activity is assumed.

Pamomorphology of flaccid skin. The epidermis is little changed, sometimes a bit atrophic. The collagen fibers of the upper part of the dermis are loosened, and the irregularity of their arrangement is revealed in the mesh layer. The number of elastic fibers throughout the dermis is markedly reduced, especially in its upper regions. There are no oxitalane fibers, and the elanin fibers are hardly noticeable in the subpapillary plexus. Elastic fibers of the reticular layer of the dermis of various thicknesses, are fragmented or granular in appearance with indistinct contours, sometimes in the form of pulverulent granules located between bundles of collagen fibers; in the lower part of the dermis, the elastic fibers are thin, long, wavy, they are absent around the hair follicles. Histochemical study revealed an increase in the content of glycosaminoglycans in the main substance of the dermis, which may be due to changes in elastic fibers. A similar pathology of elastic fibers was found in the aortic wall, in lung tissue in patients with cardiorespiratory manifestations of the disease. With electron microscopy in the papillary dermis layer, only microfibrils reminiscent of oxyta- alane fibers were detected, and there were no elanin fibers. Short, irregularly shaped or spherical elastic fibers are found in the reticular layer, located among the little-changed collagen fibers. Their matrix is electronically transparent, without microfibrils, which are usually visible among the amorphous matrix. In places where microfibrils are normally seen along the periphery of the elastic fiber, a granular-fibrillar substance is detected. Separate bundles of microfibrils are located near the elastic fibers. In these places, SR. Sayers et al. (1980) found electron-dense deposits of an amorphous substance of the same localization. In the deeper parts of the dermis, the elastic fibers are changed less, although they look thin and short, fibroblasts - with signs of enhanced protein-synthetic function.

Histogenesis of flaccid skin. Normally, microfibrils form a network that plays an important role in the orientation of elastin molecules (the so-called vector synthesis) in the lateral and "end-to-end" compounds, which ensures the normal structure of the elastic fiber and its physiological usefulness. With flabby skin, the relationship between the two main components of the elastic fiber, the protein elastin, constituting the amorphous matrix of the fiber, and the microfibrils is broken. M. Ledoux-Corbusier (1983) believes that in the autosomal recessive inherited type of flaccid skin, there is no destruction of the elastic fibers, but their underdevelopment. The absence of elanin fibers and a small amount of oxitalane indicate a breakdown of elastogenesis in its early stages. Elastogenesis is completely absent in the papillary layer and blocked in the mesh layer. In connection with this, the term "elastolysis" is inexpedient and more correctly considered the main process of generalized disturbance of elastogenesis. Some authors, besides the elastic ones, find changes in collagen fibers in the form of unevenness of their diameter and splitting, similar to that of the Chernogubov-Ehlers-Danlos syndrome. Apparently, this is due to the generality of the enzymatic regulation of individual stages of the biosynthesis of collagen and elastic fibers.

Acquired, or secondary, elastolysis unlike hereditary types occurs usually in adults as a result of various inflammatory skin diseases (post-inflammatory dermatochalasis): urticaria, burns, contact dermatitis, eczema, but can occur without previous inflammation.

Elastolysis can also be a manifestation of the Chernogubov-Ehlers-Danlos syndrome with autosomal recessive inheritance, an elastic pseudocanthoma, an autosomal dominant amyloidosis. It is believed that the basis for the development of acquired elastolysis is a hereditary predisposition, and the preceding skin diseases are only a resolving factor.

Unlike hereditary forms on the skin, except for the usual for sluggish skin manifestations, the residual manifestations of dermatosis are often visible, against which it developed. At the same time, lesions of the internal organs - lungs, heart, gastrointestinal tract, similar to those described in autosomal recessive inherited type of flaccid skin are not uncommon, which makes the above division of this disease into hereditary and acquired forms very conditional and requires the development of additional criteria.

Pathomorphy of flaccid skin. The histological picture of the acquired elastolysis, in addition to the listed changes, may include an inflammatory reaction indicating changes preceding the development of flaccid skin. In the dermis, sometimes there are lymphogistocyte infiltrates, giant cells of foreign bodies, an admixture of eosinophilic granulocytes, eosinophilic spongiosis, calcium deposits. H. Nanko et al. (1979) believe that skin changes with acquired elastolysis proceed according to the type of autoimmune reaction, which is confirmed by the description of several cases of the combination of acquired elastolysis with autoimmune diseases - multiple myeloma, systemic lupus erythematosus and skin amyloidosis. Electron microscopic examination of the skin with acquired elastolysis revealed along with normal altered elastic fibers. They are fragmented, surrounded by small short filaments, the remains of elastic fibers are seen in the form of electron-dense amorphous material. Thus, with the acquired form, destruction of normally formed elastic fibers is observed.

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