Striae

STRIAE (Latin - groove), striae, scar-like formations on the skin in the form of linear reddish-bluish, later whitish stripes, 1-2 cm in length: S. arise almost exclusively on areas of skin stretching, whence their frequent designation as S. distensae cutis. Essentially, S. are not scars, but areas of skin atrophy (Dehnungsatrophie of German authors) with a reduced content of elastic fibers and the separation, thinning of collagen bundles; the papillae in the region of S. are flattened. The indicated changes in the connective tissue framework of the skin arise, apparently, not only in connection with stretching, but also with rupture, breakdown of fibrous structures. In particular, a breakdown of elastic fibers is pointed out, forming in the region of S. a disordered entanglement of coarse and delicate, mostly short filaments. S. are observed chiefly on the lower and lateral surfaces of the abdomen, on the thighs, in the region of the patella. The first two localizations are most often associated with pregnancy (see Striae gravidarum), as well as with stretching of the abdomen in ascites, abdominal tumors, its obesity, and the like. S. patellares in the form of stripes running transversely to the axis of the leg are observed in various infectious diseases (typhoid fever, dysentery, osteomyelitis) and are associated, apparently, with some trophic changes in the skin, and on the other hand, with overstretching of the latter, since patients often keep their legs in a semi-flexed position. The presence of patellar S. can serve as an indirect indication of a severe disease suffered at some time. - It would be erroneous, however, to associate the occurrence of S. exclusively with the mechanical factor of stretching of the integuments. The state of the skin itself in the sense of its elasticity, contractility also plays an important role. A small part of S. arises on the basis of dystrophic disorders in the skin as the primary moment. This should include S. of the abdomen in some endocrine disorders and intoxications. In these cases, even light skin tension, noted under physiological conditions as well, proves sufficient to induce S. Indirectly, this is also proved by the circumstance that simultaneously with skin S. in the corresponding subjects, trophic disorders of the subcutaneous adipose layer can also be discovered.