Local panatrophy with linear distribution: a clinical, ultrastructural and biochemical study.

A young female with local panatrophy of the right-side extremities affecting all mesodermal layers--dermis, subcutaneous tissue, muscles, and bone--is described. The atrophies were strictly linear. Ultrastructurally, collagen fibrils of the reticular dermis from the atrophic area consisted of two types, a large population of fibrils with decreased diameter and round cut-surface, and a small population with increased diameter and a "flower-like" cut-surface. Collagen analysis revealed a reduced hydroxyproline concentration and content per mm2 skin in atrophic area as compared with the perilesional and regional control. Urinary excretion of hydroxyproline was normal. Glycosaminoglycan analysis showed a less reduced content of hexosamine and uronic acid in the atrophic area per mm2 skin, but no differences in the concentrations. Consistently, the gel/fibre ratio (uronic acid/hydroxyproline) was found slightly elevated in atrophic skin. The proportions of the individual glycosaminoglycans heparin, dermatan sulphate, hyaluronic acid and chondroitin sulphates were not affected. It is concluded that reduced collagen and ultrastructural changes of collagen fibrils are significant features in local panatrophy. The significance of local foetal factors affecting the somatic mesoderm is discussed.