Asphyxial deaths and petechiae: a review.

Conjunctival and facial petechiae, although nonspecific findings, are considered hallmarks of asphyxial deaths. Consensus in the literature suggests that their pathogenesis is related to the combined effects of increased cephalic venous pressure and hypoxic damage to endothelial cells. Despite the common knowledge that they are neither predictable findings in all asphyxial deaths nor rare in natural, nonasphyxial deaths, the belief persists that petechiae are corroborative evidence of asphyxia. We suggest that a clear, physiologically based understanding of the pathogenesis of petechiae of the head is critical for their appropriate interpretation. We present a review of the literature and the basis of our conclusion that conjunctival and facial petechiae are the product of purely mechanical vascular phenomena, unrelated to asphyxia or hypoxia.