Restrictive dermopathy: a case report and a critical review of all hypotheses of its origin.

Restrictive dermopathy (RD) is a rare, fatal, autosomal recessive genodermatosis in which tautness of a translucent thin skin is the major clinical observation. This causes an intrauterine fetal akinesia deformation sequence (FADS) resulting in polyhydramnios, reduced fetal movements at around 31 weeks gestation, dysmorphic facies, arthrogryposis, and early neonatal death because of respiratory insufficiency. The characteristic histologic abnormalities of the skin are located in a thin dermis, consisting of compactly arranged collagen fibers, scant elastic fibers, and poorly developed skin appendages. The epidermal rete ridges are flattened and the dermal-hypodermal border is remarkably straight. The etiology of these changes remains unclear. We tested several existing hypotheses and could not confirm them. These included fibroblast dysfunction, abnormal keratin composition, desmosomal changes, and increased proinflammatory cytokines [tumor necrosis factor (TNF)-alpha and interleukin (IL)-6]. We conclude that RD is a relatively easy clinical and pathologic diagnosis, but that the pathogenesis of the disease is not clarified.