Caustic substances injure tissue by means of a chemical reaction on direct physical contact. The term “corrosive” is often used interchangeably with “caustic,” however, corrosion implies mechanical degradation, which does not always apply to caustics. Caustics are present both at home and at work. Common caustic substances include classic alkalis like ammonium hydroxide, a general cleaner and grease remover, sodium or potassium hydroxide (lye), used as drain cleaner, oven cleaner, grease remover, and hair relaxer, and sodium hypochlorite (bleach), used as a laundry whitening agent and swimming pool chlorinator. Classic acids include acetic acid, used in food pickling and photo developing, hydrochloric acid, used as a toilet cleaner and mold and mildew remover, oxalic acid, used in metal polish, phosphoric acid, used for rust removal, selenous acid, used for gun bluing, and sulfuric acid, used as a drain opener and in large lead-acid batteries. Other caustic agents include benzalkonium chloride, a surface cleaner and preservative, hydrofluoric acid, a rust and graffiti remover, hydrogen peroxide, a surface, wound, and food cleaner, phenol, a surface disinfectant, and zinc chloride, used in soldering flux.
Currently, poison control centers and the CDC advise “up and away” storage of all caustic substances to keep the out of reach of children, but caustic-induced injuries in children remain a serious health concern in the U.S. Nearly 1,000 children with caustic ingestions are hospitalized every year, on average for four days, with direct hospital costs of more than $22 million. Caustic exposures are divided on the basis of intention. In children, they are usually exploratory and mostly involve small amounts. The unfortunate exceptions are the rare but dramatic alkali ingestions reported as manifestations of child abuse. In contrast, adolescents and adults usually ingest larger amounts in deliberate attempts at self-harm. These intentional ingestions are often much more severe.
Clinical effects of caustic ingestions are divided into immediate, delayed, and remote manifestations. Organ systems typically involved are the eyes, skin, airway, and gastrointestinal tract. Following ingestion or contact, pain is often immediate, followed by loss of function. Manifestations of oral ingestion include swelling of the tongue and mouth, drooling, and vomiting. Bleeding can be severe if the injury involves erosion into a blood vessel. Swelling of the airway causes stridor (a loud wheezing or rasping sound coming from the throat area), respiratory compromise, and voice changes. Perforation of the esophagus, stomach or bowel may occur. Survivors of the acute episode may experience both delayed and remote complications. Eye and skin injuries have cosmetic and functional implications. Esophageal strictures (scarring and narrowing of the esophagus) may develop over time following ingestion, and esophageal cancers may develop decades later.
The key to treatment, especially in children, is prevention. Getting dangerous substances out of the reach of curious hands is paramount. For more information on prevention, go to www.upandaway.org
By Peter Galvin, MDBLOG COMMENTS POWERED BY DISQUS