Coin vs battery - Imaging of Foreign bodies

Abstract

A previously well 2 year old female presented to a peripheral emergency department following the ingestion of a foreign body. Her parents reported witnessing her swallow a coin, 2 days prior to presentation. She subsequently developed 24 hours of non-bilious vomiting followed by epigastric pain and decreased oral intake. The child was referred to a tertiary centre for review. On physical examination the child was alert but lethargic with tachycardia to 164 and a fever of 38.9 degrees. She had no drooling, increased work of breathing or stridor. Auscultation revealed equal air entry, normal heart and bowel sounds. Abdomen was soft, non tender without distension. She was treated with antipyretics and chest and abdominal imaging was arranged. AP chest radiograph and plain abdominal images revealed a circular 2 cm radiopaque object located in the stomach. On review by radiology the object appeared to have a 'halo sign', a feature consistent with button batteries. Given the uncertain origin of the object and potential for complications associated with button battery ingestion our patient was fasted for an endoscopy. Endoscopy revealed two 10 cent coins sitting in the gastric antrum with localized erosions and erythema. These were successfully removed with a Roth net and the patient was discharged the same day. Foreign body (FB) ingestion/inhalation most commonly occurs in children aged between six months and three years. The most common objects are coins, reported in up to 88% of cases. (1) FB ingestion usually only requires imaging followed by clinical observation. Coins are unlikely to cause complications, whereas button batteries pose a risk of metal poisoning, burns, oesophgeal strictures, perforation, tracheooe-sophgeal and aorto-oesophgeal fistula and haemorrhage.(2) One study revealed that 14% of children with oesophageal FBs were asymptomatic on presentation, highlighting the need for imaging. Recommended investigations include AP and lateral neck, AP and lateral chest and abdominal radiographs. (4) The sensitivity of plan films in detecting a battery was 80.4%, specificity 79.1% with an overall accuracy of 79.8%. The same study demonstrated that stacking two coins on top of each other lead to high rates of misidentification as batteries with an overall accuracy below 60%. (1) Importantly this study used artificially produced images which therefore did not include soft tissues and bony structures which could prevent accurate identification. This case highlights the importance of accurate identification of foreign objects and the need for high clinical suspicion of FB.L6286819762019-08-01 <br />