silver nitrate, concentrated hydrogen peroxide) Strong alkalis and acids cause direct destruction of tissue but with differing histopathologic patterns Acids produce coagulation necrosis that usually causes superficial damage, rather than deep, penetrating burns Alkalis, in contrast, cause a deep and penetrating liquefaction necrosis, which often has severe consequences, such as esophageal perforation Such deep burns are often associated with severe scarring and, ultimately, with stricture formation ( Fig 102.6 ) Acid caustics include the mineral acids, such as hydrochloric, sulfuric, nitric, and hydrofluoric acids Common household products that contain acid caustics include toilet bowl and drain cleaners