# Foreign Body and Corrosive Ingestion > Foreign body and corrosive ingestion for NEET-PG Paediatrics: button battery and magnet emergencies, endoscopy indications and management of corrosive injury. - Canonical URL: https://prepelephant.com/topics/neet-pg/paediatrics/foreign-body-and-corrosive-ingestion - Exam / course: NEET-PG · Subject: Paediatrics - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-08 - Last updated: 2026-10-08 - Reference basis: Nelson Textbook of Pediatrics; Ghai Essential Pediatrics - How to cite: "Foreign Body and Corrosive Ingestion", PrepElephant, https://prepelephant.com/topics/neet-pg/paediatrics/foreign-body-and-corrosive-ingestion ## Direct answer Foreign body ingestion in children is most often a coin or small toy, but button batteries, magnets and caustic agents cause the most serious injuries. An oesophageal button battery causes alkaline necrosis within hours and needs urgent removal, while two or more ingested magnets can perforate bowel by attracting across the wall. Corrosive ingestion, usually alkali, is managed by avoiding vomiting and neutralisation, with early endoscopy and follow-up for stricture. ## What you must remember - **Button battery:** an oesophageal battery is an emergency; removal is needed urgently, ideally within two hours of confirmed lodging. - **Magnets:** a single magnet usually passes, but two or more magnets, or a magnet with metal, can attract across bowel walls and cause necrosis, fistula or perforation. - **Coins and sharp objects:** a coin lodged in the oesophagus is removed endoscopically, though an asymptomatic child may be observed briefly for spontaneous passage; sharp objects within endoscopic reach are removed urgently. - **Alkali versus acid:** alkali causes liquefactive necrosis and deeper injury; acid causes coagulative necrosis, which limits penetration. - **Zargar grading:** endoscopic grades from 0 to IIIb; grade IIb and above carries a higher risk of stricture. - **Initial management:** no emesis, no charcoal and no neutralising agent; airway assessment is essential when oral burns or stridor are present. - **Endoscopy timing:** early endoscopy, usually within the first 24 hours, for corrosive injury and for objects that are not passing. - **Steroids:** not used routinely to prevent stricture. ## A graded approach to the child who swallowed something A 2-year-old is brought after a witnessed swallow of an unknown object, and a bottle of drain cleaner is found nearby. The first task is to identify which emergency is present, because the responses differ. 1. **Confirm and localise.** Obtain a chest and abdominal radiograph; a button battery on an anteroposterior film gives the classic double-ring sign. 2. **Prioritise the emergencies.** An oesophageal battery or multiple magnets need urgent removal, and any corrosive ingestion needs same-day specialist review. 3. **Protect the airway.** Oral burns, drooling or stridor after a corrosive ingestion require early airway assessment. 4. **Avoid harmful measures.** No emetics, no neutralisation and no blind nasogastric tube. 5. **Arrange endoscopy.** Early endoscopy for corrosives, and for objects in the oesophagus, sharp objects or persistent symptoms. 6. **Monitor and follow up.** Watch for dysphagia and drooling; stricture is managed by serial dilatation. ## Where the exam tries to catch you Ingestion vignettes often hinge on one feature that changes the emergency. - **Trap:** inducing vomiting after a corrosive ingestion. **Correct:** emesis causes a second injury to the oesophagus, so it is avoided and endoscopy is arranged. - **Trap:** waiting for an oesophageal button battery to pass. **Correct:** a battery in the oesophagus must be removed; wait-and-watch applies only to a battery confirmed beyond the stomach in an asymptomatic child. - **Trap:** neutralising an alkali injury with an acid. **Correct:** neutralisation adds heat and injury, so it is not recommended for any corrosive ingestion. - **Trap:** assuming a single magnet is always harmless. **Correct:** a single magnet usually passes, but any second magnet or magnet-metal pair demands urgent removal. ## Frequently asked questions ### Why is an oesophageal button battery treated as a surgical emergency in children? An oesophageal button battery is treated as a surgical emergency because it generates current and hydroxide at its surface, causing rapid alkaline necrosis. Serious injury, perforation and fistula can follow within hours, so the battery must be removed urgently. ### Which Zargar grade predicts a higher risk of oesophageal stricture after corrosive injury? Zargar grade IIb and above, meaning deep ulceration and beyond, predicts a higher risk of oesophageal stricture after corrosive injury. These children need closer endoscopic follow-up and planning for dilatation. ### Why should vomiting not be induced after corrosive ingestion in a child? Vomiting should not be induced after corrosive ingestion because the caustic agent is brought back up through the oesophagus and mouth. This causes a second injury to tissue already damaged, and the child should instead be taken for early endoscopy. ### When are two or more ingested magnets removed in children? Two or more ingested magnets are removed urgently, because they can attract across the bowel wall and cause pressure necrosis, fistula or perforation. Removal is usually endoscopic in the oesophagus or stomach and surgical if the magnets have moved into the intestine. ### Which radiological sign suggests a button battery lodged in the oesophagus? The double-ring sign on an anteroposterior radiograph suggests a button battery lodged in the oesophagus. A battery lying flat on the face of the film produces this appearance, and it is a reason for urgent endoscopy.