Corrosive (caustic) ingestion: what to do, hospital care and complications

Corrosive substances damage tissue on contact. The MSD Manual explains that caustic substances, meaning strong acids and alkalis, burn the tissues of the upper digestive tract when swallowed. Common sources include solid and liquid drain cleaners, toilet bowl cleaners and laundry detergent pods, and industrial products are usually more concentrated than household ones and so tend to be more damaging.

How the injury develops depends on the substance. The MSD Manual says acids cause coagulation necrosis, with an eschar forming that limits further damage, and tend to affect the stomach more than the gullet. Alkalis cause rapid liquefaction necrosis in which no eschar forms and damage continues until the alkali is neutralised or diluted, tending to affect the gullet more than the stomach. Solid products tend to stick to tissues and burn locally, which discourages further swallowing, whereas liquids do not stick, so larger quantities are easily swallowed and damage can be widespread. Liquids may also be breathed in, injuring the airway.

This is a form of poisoning. The NHS describes poisoning as happening when you swallow, touch or breathe in harmful substances, including household cleaning products such as bleach or laundry detergents.

The NHS says to call 999 or go to A&E if you think you, a child or someone else may have swallowed something harmful, if someone has lost consciousness or stopped breathing, has severe difficulty breathing or has a seizure. Get medical advice immediately even if the person looks well, because the NHS notes symptoms may take a few hours or days to start. NHS inform adds the steps for first aid: identify the poison if the person can respond and, if possible, how much and when; phone 999 and give the call handler as much information as possible; and monitor the person's level of response, breathing and pulse.

While waiting, the NHS advises to start CPR if the person is unresponsive and not breathing, to put them in the recovery position if unconscious but breathing, to keep checking their breathing and to look for what caused the poisoning, taking the substance or its packaging to hospital if possible. NHS inform says that if the casualty's lips are burnt you can give frequent small sips of cool water or milk, and that if the casualty is contaminated with chemicals you should wear protective gloves, goggles or a mask.

The NHS says not to try to make someone sick and not to give them anything to eat or drink. The MSD Manual explains why in clinical terms: causing vomiting can re-expose the upper digestive tract to the caustic, and attempts to neutralise an acid with an alkali, or the reverse, can cause a severe heat-producing reaction that may worsen the damage. If advice from NHS inform and the NHS pages differ about small sips of water or milk, follow what the ambulance call handler or clinician tells you.

The MSD Manual says initial symptoms include drooling and difficulty swallowing, and in severe cases pain, vomiting and sometimes bleeding in the mouth, throat, chest or abdomen. Airway burns may cause coughing, fast breathing or noisy breathing (stridor). It warns that swollen, red tissue may be visible in the mouth, but caustic liquids may cause no burns in the mouth despite serious injury farther down.

Perforation of the gullet may cause severe chest pain, fast heartbeat, fever, fast breathing and shock, and perforation of the stomach may cause peritonitis. The MSD Manual adds that perforation may occur within hours, after weeks or any time in between. NHS inform lists vomiting that may be blood-stained, stomach cramps and abdominal pain, pain or a burning sensation, reduced level of response, and breathing difficulties as signs of poisoning from a swallowed substance.

The MSD Manual says that because the presence or absence of burns in the mouth does not reliably indicate whether the gullet and stomach are burned, careful endoscopy is indicated to check for the presence and severity of burns when symptoms or history suggest more than a trivial ingestion. It says endoscopy does not need to be done immediately and that the patient should be stabilised first. A chest X-ray has limited sensitivity for perforation, so a CT scan of the chest and abdomen is done if perforation is suspected.

The NHS says that if you do not have symptoms you may not need treatment, but you may still need to be monitored for several hours in case you become unwell. Bring the container or product label to hospital if you can, and tell staff what, how much and when.

The MSD Manual says treatment of acid and alkali ingestion is similar and mainly supportive. Gastric emptying by vomiting or lavage and activated charcoal are contraindicated, because charcoal does not absorb caustics and can interfere with endoscopy. Dilution with milk or water is only useful in the first few minutes after swallowing a liquid, and should be avoided if there is nausea, drooling, noisy breathing or signs of perforation. Corticosteroids and preventive antibiotics are not recommended, whereas perforation of the gullet or stomach is treated with antibiotics and surgery.

The NHS says people with poisoning are treated in hospital because it can make you seriously unwell and be life threatening, with treatment depending on what caused it and which may include antidotes, treatments to help with symptoms and fluids into a vein.

The MSD Manual says oesophageal strictures can develop over weeks even if initial symptoms were mild and treatment adequate, and can result in shortening or narrowing of the gullet as well as swallowing difficulty and motility disorders. Strictures are treated with a dilating procedure (bougienage) or, if severe or unresponsive, with surgical bypass of the gullet. It also notes that survivors of caustic ingestion have a higher risk of developing oesophageal cancer, which is why long-term follow-up is part of care.

See a GP promptly for difficulty swallowing, food sticking, weight loss or repeated vomiting in the weeks and months after a corrosive injury. The NHS dysphagia advice is to ask for an urgent GP appointment or call NHS 111 for difficulty swallowing, coughing or choking when eating, or a feeling that food is stuck.

The NHS suggests storing medicines and chemicals out of reach of children, ideally in a locked cupboard, putting safety catches on low cupboards that contain harmful products, and keeping liquid cleaning products in their original containers to avoid mistaking them for drinks. The MSD Manual lists laundry detergent pods among common sources of caustic ingestion, so keep them out of sight and reach.

The MSD Manual notes that in adults many caustic ingestions are intentional. If you are having thoughts of harming yourself, please tell someone, speak to your GP, call NHS 111 to be directed to urgent mental health support or, in an emergency, call 999. Samaritans are available at any time to listen.