Caustic Substances Poisoning
When swallowed, caustic substances can burn all tissues they touch—from the lips to the stomach.
Symptoms may include pain (particularly with swallowing), coughing, shortness of breath, and vomiting.
A doctor inserts a flexible viewing tube down the esophagus to look for burns and determine the severity of the injury.
Treatment is determined by the extent of the damage and may involve surgery.
(See also Overview of Poisoning.)
Worldwide, 80% of caustic ingestions occur in young children; these are usually accidental ingestions of small amounts and are often not very harmful. In adults, ingestions of caustic substances are frequently intentional, involve large amounts, and are life-threatening.
Common sources of caustics include solid and liquid drain and toilet bowl cleaners. Industrial products are usually more concentrated than household products and thus tend to be more damaging. However, some common household products, including drain and toilet bowl cleaners and some dishwasher detergents, contain damaging caustic substances, such as sodium hydroxide and sulfuric acid.
Caustic substances (strong acids and alkalis), when swallowed, can burn the tongue, mouth, esophagus, and stomach. These burns may cause perforations (holes) of the esophagus or stomach. Food and saliva leaking from a perforation cause severe, sometimes deadly infection within the chest (mediastinitis or empyema) or abdomen (peritonitis). Burns that do not perforate can result in scarring of the esophagus and stomach.
Caustic substances are available as solids and liquids. The burning sensation of a solid particle sticking to a moist surface (such as the lips) may prevent a person from consuming much of the product. Because liquids do not stick, it is easier to consume more of the product, and the entire esophagus can be damaged. Liquids also may be inhaled (aspirated) into the airways, leading to upper airway injury.
Pain in the mouth and throat develops rapidly, usually within minutes, and can be severe, particularly with swallowing. Coughing, drooling, an inability to swallow, vomiting, vomiting blood, and shortness of breath may occur. In severe cases involving strong caustic substances, a person may develop very low blood pressure (shock), difficulty breathing, or chest pain, possibly leading to death.
Perforation of the esophagus or stomach may occur within hours, during the first week after ingestion, or any time in between, often after vomiting or severe coughing. The esophagus may perforate into the area between the lungs (the mediastinum) or into the area surrounding the lungs (the pleural cavity). Either circumstance causes severe chest pain, fever, rapid heart rate, rapid breathing, very low blood pressure, and the need for surgery. Peritonitis results in severe abdominal pain when the stomach perforates.
Scarring of the esophagus results in narrowing (stricture), which causes difficulty in swallowing. Strictures usually develop weeks after the burn, sometimes in burns that initially caused only mild symptoms. People with scars and damage to the esophagus may develop cancer of the esophagus years after the injury.
The mouth is examined for chemical burns. Because the esophagus and stomach may be burned without the mouth being burned, the doctor may insert a flexible viewing tube (endoscope) down the esophagus to look for burns, particularly if the person drools or has difficulty swallowing. Directly inspecting the area allows the doctor to determine the severity of the injury and possibly to predict the risk of subsequent narrowing and the possible need for surgical repair of the esophagus. Endoscopy can be delayed if the person is too sick for the procedure.
X-rays and computed tomographic (CT) scans may be necessary to evaluate the extent of the injury.
The extent of damage determines treatment. People with severe burns sometimes need immediate surgery to remove severely damaged tissue.
Because caustic substances can cause as much damage when returning up the esophagus as they did when swallowed, a person who has swallowed a caustic substance should not be made to vomit. Syrup of ipecac and charcoal are not given.
If burns are mild, the person may be encouraged to begin drinking milk or water fairly soon in order to dilute the corrosive liquid in the stomach. Drinking can begin at home or on the way to the hospital. If the person cannot drink, fluids are given by vein until drinking is possible. Perforations are treated with antibiotics and surgery. If strictures develop, a bypass tube (stent) may be placed in the narrowed portion of the esophagus to prevent the esophagus from closing and to allow for future widening (dilation). Repeated widening may be needed for months or years. For severe strictures, surgery to rebuild the esophagus may also be necessary.