An 86-year-old man presented to the emergency room with vomiting and melena. The patient was hemodynamically stable and remained alert and orientated. According to his family, ingestion of a pack of disposable hand warmers, which he mistook for black sesame powder, occurred 17 h prior to admission. Before ingestion, he mixed the powder with warm water. Physical examination revealed no thermal injury of the oral mucosa with no abdominal pain or tenderness. An abdominal plain film showed multiple scattered radiopaque material with zonal distribution over the right abdomen. An intravenous 500-mg deferoxamine challenge test showed no vin rosé urine discoloration. Serial serum iron levels remained within the normal range. The patient remained clinically stable with no medical complications. He was discharged 3 days after admission. The hand warmers consisted of iron powder (50% w/w), sodium chloride, activated charcoal, and nontoxic vermiculite: a potential risk for intestinal thermal injury. In this case, the water added beforehand rapidly terminated the iron oxidation reaction. This explained the lack of thermal injury. Ferric oxide is poorly absorbed by the digestive tract and explained the absence of iron intoxication. Therefore, clinicians should clarify the method of ingestion. If a hand warmer has been premixed with water, less mucosa injury can be expected with a lower risk of iron intoxication. This report also provided evidence that abdominal plain films can be used to confirm the ingestion of iron and monitor its elimination.
Keywords: Hand warmer; digestive tract; ferric oxide; iron oxidation; thermal and corrosive injury.