Diagnostics and Therapeutics: Caustic Ingestions in the Emergency Department
/Acids and alkalis are caustics, which by definition cause tissue injury upon contact. Ingestion of acids and alkalis can lead to dire emergencies – notably airway compromise or GI perforation. Fortunately, there are evidence-based measures that can be taken to resuscitate and stabilize these patients in the ER. This post is an overview of the damage caustic ingestion can cause, and what the ER physician needs to do about it.
How do acids and alkalis cause damage?
A caustic substance, by definition, is a substance with chemical properties that can cause burn and/or corrosion injuries to tissue upon contact. The majority of caustic injuries are due to oral ingestions, causing injury to the GI tract – in particular the mouth, throat, esophagus, and stomach. However ingestion of caustic substance can also lead to unintentional aspiration and subsequent injury to the airways and lungs as well. Acids tend to cause upper airway injuries more commonly than alkalis do, perhaps because of their bad taste which stimulates gagging, choking or spitting. Although clinically acid and alkali ingestions cause similar symptoms, the mechanisms by which they cause damage is distinct.
Alkalis cause penetrating injury through liquefactive necrosis, which involves saponification and subsequent cell lysis. Transmural damage can ultimately cause perforation. When the alkali enters the stomach, partial neutralization by gastric acid may result in more limited injury. This may be why alkalis cause less duodenal injury than in the stomach, and less gastric injury than in the esophagus.
In contrast, acids cause tissue injury through coagulation necrosis. This does form a protective eschar, but acid ingestion can also ultimately cause perforation. In addition, acids tend to cause less esophageal injury than alkalis as they are often less viscous and pass quickly into the stomach rather than linger on the esophagus.
The extent of possible tissue damage can be estimated by the pH of a substance, although there is more accurate scale used called the “titrable acid or alkali reserve” (TAR) score which is defined by the amount of acid or base needed to neutralize a caustic substance's pH. Examples of caustic substances with a high TAR include ammonia surface cleaner, batter acid, liquid toilet bowl cleaner. Examples of caustic substances with a low TAR include over the counter bleach and laundry and dish detergents.
In addition to the TAR score, other factors that influence how much tissue damage is caused by a caustic substance include tissue contact time, amount of substance ingested, and type of substance ingested (i. e. liquid, solid, gel form).
What acids and alkalis are commonly ingested?
The most common ingestions that occur with alkali substances include lye (sodium hydroxide or potassium hydroxide - which is found in drain cleaners), hair relaxers, grease removers, ammonia, detergents (including tide pods involved in the viral “tide pod challenge” a few years ago), and bleach. Bleach is the most common household alkali with a pH of 11. For reference, alkalis with a pH above 12 will cause more serious tissue damage.
original image created by author with individual pictures all under creative commons licenses from wikimedia commons
https://commons.wikimedia.org/wiki/File:Corroded_batteries_dscn6962.jpg
https://commons.wikimedia.org/wiki/File:Laundry_detergent_pods.jpg
https://commons.wikimedia.org/wiki/File:Clorox_Bleach_products.jpg
It is important to note that in the US, household bleaches rarely cause serious injury, but bleaches from other countries or industrial strength bleaches will have a higher pH and thus cause more damage. Household strength alkalis generally need to be ingested in higher volumes (200-300 mL) to cause serious damage. However, concentrated forms of these chemicals- such as capsules, gel packs or pods- are more likely to cause significant caustic injury due to the total concentration ingested and increased tissue contact time.
Acid ingestions are less common in the US than alkali ingestions. Common acid ingestions include toilet bowl or swimming pool cleaners, rust removers, battery fluid, metal cleaners or polishers.
How do patients present to the emergency department?
The presentation can vary wildly, from asymptomatic to cardiac arrest. Caustic ingestion is often intentional in adults whereas it is frequently accidental in children, meaning adults tend to ingest more volume and have more severe injuries. Here are some of the signs and symptoms you may see:
oropharyngeal, retrosternal, epigastric or other abdominal pain
voice changes
stridor
opharyngeal or airway edema
hypersalivation, difficulty clearing secretions
dysphagia/odynophagia
vomiting
hematemesis
subcutaneous emphysema (you might notice Hamman’s sign!)
tenderness/guarding/rigidity (peritonitis)
vital sign abnormalities (tachycardia, tachypnea, hypotension, fever)
What labs and imaging should I order?
Completion of EGD is the gold standard in evaluating and diagnosing significant injuries. Sometimes patients may not present with any obvious signs of injury, and therefore some caustic injuries may present in a delayed fashion as the necrosis of tissue and scar formation progresses over hours to days. Labs and imaging are often ordered BUT the long term prognosis and estimation of injury extent is more often based on severity of physical exam findings in addition to the type and amount of substance ingested. In general, the presence of a leukocytosis, thrombocytopenia, high C-reactive protein, (lactic) acidosis, renal failure and liver function test derangements are predictive of transmural necrosis and poor outcomes.
Here are some laboratory tests you should consider ordering:
CBC
BMP
Mg (hydrofluoric acid can cause severe hypomagnesemia)
VBG and lactate
LFTs
CRP
Coagulation profile (coagulopathy is a potential complication)
Type and screen (patients may need blood transfusion in the setting of a needed surgery and / or GI bleed)
Salicylate, ethanol and acetaminophen level (if concerned about co-ingestion)
A chest and abdominal X ray can be very useful when determining whether a patient has suffered perforation. It can also be used to identify pulmonary infiltrates from aspiration. Some findings of perforation include:
Pneumoperitoneum on x-ray with red and green arrows on the left indicating air under the diaphragm and blue arrows on the right indicating rigler’s sign (when gas is noted to outline the bowel, a secondary sign of pneumoperitoneum). image shared under CC A - SA 3.-0 unported license. https://commons.wikimedia.org/wiki/File:Pneumoperitoneum.jpg. accessed on June 11, 2025.
Pneumomediastinum
Mediastinal widening
Subcutaneous air
Pleural effusions
Subdiaphragmatic air
The use of contrasted CT scans of the chest and abdomen in evaluating caustic ingestion has received a fair amount of attention in the literature recently. It is a quick, non-invasive and reliable means of identifying patients who need emergent surgery. Most studies show that contrasted CTs have a high specificity for injury, but low sensitivity. Therefore while they can be a useful adjunct in the ER, they should not serve as a replacement for EGD at this time, particularly in patients with large ingestions.
What can I do in the ER to stabilize and resuscitate these patients?
Some patients will not require anything other than observation. Asymptomatic patients with accidental ingestion of a small volume of low concentration acid or alkali can be discharged after 4-6 hours of observation. They should be re-examined and pass a PO challenge without difficulty or pain prior to discharge. These patients may still benefit from GI follow up and EGD as an outpatient to monitor for long term complications.
For more symptomatic patients or patients with large ingestions, ABCs come first!
One study showed that up to 50% of adults with large caustic ingestion will require intubation. Caustic ingestion can compromise the airway due to oropharyngeal edema, friable/necrotic tissue, and bleeding. It is best practice to examine the airway with a fiberoptic device, and if needed perform video laryngoscopy-assisted or fiberoptic-assisted intubation. Avoid blind intubation, LMAs and bougies due to the risk of perforation. Prepare to perform a surgical airway as backup. This is also a situation where awake fiberoptic intubation may make sense due to likelihood of a difficult airway. Consider intubating early when suspicious of significant ingestion to improve patient outcomes and reduce airway complications.
Along with airway compromise, patients with caustic ingestion may exhibit hemodynamic compromise due to hemorrhage from erosion into vasculature, perforation or from third spacing. Prepare to give fluids and blood products as necessary.
esophagram imaging of young man with lye ingestion 2 years prior - esophagram shows esophageal stricture as long term complication. image shared under CC BY-NC-SA 2.0. https://www.flickr.com/photos/radquiz/4277283582/in/photostream/. Accessed June 11, 2025.
Medications commonly administered include anti-emetics to prevent aspiration risk as well as broad-spectrum antibiotics for those with suspected perforation. Emetics and neutralizing agents can be harmful and should be avoided. The use of proton pump inhibitors has been studied some in the literature and may help reduce the severity of esophageal injury. The use of corticosteroids is controversial. There is also some evidence that they can help with airway edema and prevent stricture formation in Grade 2B esophageal injuries, but should only be used on conjunction with GI consultation.
Most symptomatic patients will benefit from upper endoscopy to evaluate the extent of damage. Studies recommend performing EGD within the first 24 hours of ingestion to evaluate injury extent. Again, consult your GI colleagues promptly. The exception is patients who require surgery. These will be patients who have perforated, as suggested by imaging, physical exam, or labs (such as persistent lactic acidosis). In this case, consult your surgery colleagues emergently and resuscitate your patient for the OR.
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LONG TERM COMPLICATIONS
It is important to remember after initial stabilization and evaluation that patients also need to have a good follow up plan to evaluate for and prevent long term sequelae. Complications that can occur include upper GI bleeding 2-4 weeks after ingestion, tracheoesophageal fistulization several months after ingestion, esophageal strictures (which occur in up to 30% of caustic ingestions), and esophageal cancer several years after injury. Patients will therefore require follow up with GI for outpatient EGDs to monitor for these complications.
POST BY BUSHRA AMIN, MD
Dr Amin is a PGY-1 in Emergency Medicine at the University of Cincinnati.
EDITING BY ANITA GOEL, MD
Dr Goel is Associate Professor in Emergency Medicine at the University of Cincinnati and an assistant editor of TamingtheSRU.com.
Cite As: Amin B., Goel A. Diagnostics and Therapeutics: Caustic Ingestions in the Emergency Department. TamingtheSRU. www.tamingthesru.com/blog/caustic-ingestions-in-the-emergency-department. 6/23/2025.
References
1. Fishman DS. Caustic esophageal injury in children. UpToDate. Published Aug 21, 2024. Accessed May 22, 2025. https://www.uptodate.com/contents/caustic-esophageal-injury-in-children
2. Triadafilopoulos G. Caustic esophageal injury in adults. UpToDate. Published Feb 29, 2024. Accessed May 22, 2025. https://www.uptodate.com/contents/caustic-esophageal-injury-in-adults
3. Judkins DG, Chen RJ, McTeer AV. Alkali Toxicity. [Updated 2023 Oct 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. Available from: https://www.ncbi.nlm.nih.gov/books/NBK544235/
4. Bielecki JE, Chen RJ, Gupta V. Caustic Ingestions. [Updated 2024 Jan 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557442/
5. Bouchard NC, Carter WA. Caustic Ingestions. In: Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8e. McGraw-Hill; Accessed May 22, 2025.
6. Hoffman RS, Burns MM, Gosselin S. Ingestion of Caustic Substances. N Engl J Med. 2020 Apr 30;382(18):1739-1748.
7. Chirica M, Bonavina L, Kelly MD, Sarfati E, Cattan P. Caustic ingestion. Lancet. 2017 May 20;389(10083):2041-2052.
8. Bruzzi M, Chirica M, Resche-Rigon M, Corte H, Voron T, Sarfati E, et al. Emergency Computed Tomography Predicts Caustic Esophageal Stricture Formation. Ann Surg. 2018 Mar 12. 22 (10):1659-1664.
9. Boukthir S, Fetni I, Mrad SM, Mongalgi MA, Debbabi A, Barsaoui S. Corticothérapie à forte dose dans le traitement des oesophagites caustiques sévères chez l'enfant [High doses of steroids in the management of caustic esophageal burns in children]. Arch Pediatr. 2004;11(1):13-17.
10. Brambl, Wells. (2021, April 29th). Titratable acid reserve. EMTOX: Musings and Studies on Toxicology and Emergency Medicine. Available from https://emtox.org/titratable-acid-reserve/
