What is a significant chemical mechanism of injury caused by button batteries?

The significant chemical mechanism of injury caused by button batteries primarily involves electric current and the resultant liquefactive necrosis. When a button battery is lodged in a body cavity, especially in the esophagus, it creates a continuous electrical current that can lead to tissue damage. This current causes the electrolytic reactions at the battery's anode and cathode, which leads to the production of alkaline substances (like sodium hydroxide) that can rapidly erode local tissues. This process results in liquefactive necrosis, where the impacted tissue becomes necrotic and transforms into a liquid viscous material due to the breakdown of cells.

While other mechanisms may also pose risks, such as thermal injury from the heat generated by current flow or mechanical obstruction due to the battery's physical presence, these do not represent the predominant chemical reaction leading to significant tissue damage. The chemical erosion from the battery's alkali reaction in conjunction with the electric current poses the most dangerous dynamic, particularly if the battery remains in place for an extended duration. This understanding aids in recognizing the urgency of removing button batteries when ingested or lodged to prevent severe injury.