One Pill Can Kill: Iron Toxicity

You are called to a suburban daycare at noon for a 2-year-old girl. On arrival you find your patient looking unwell with tachycardia, tachypnea, and pallor. You immediately recognize this is a sick child.

The daycare staff tells you she arrived at 8 a.m. feeling well. The father told daycare staff she’d had abdominal pain and vomiting into the early hours of the morning after a visit to his parents’ house to celebrate their 60th wedding anniversary, but by 1 a.m. the girl’s stomach had settled, and she went to sleep. This morning there was a bit of blood in the toilet after her bowel movement, but it was a very small amount, and the father didn’t make anything of it. The girl ate a normal breakfast and felt fine when she was dropped off at daycare. She has no medical history and no developmental delays.

Your physical exam shows a pale, unwell-looking child who is oriented. She moans when you palpate her abdomen—the upper is more painful than the lower. There is no peritonitis. Capillary refill is four seconds peripherally and two seconds centrally. Her glucose is normal. Vitals show hypotension for her age and a normal oxygen saturation. You transport her emergently to the closest emergency room about 10 minutes away.

The challenge:

• List five toxic ingestions and five nontoxic conditions that could be causing this child to be sick.
• Regardless of the cause, what are three supportive actions you can take for this child?

Iron Toxicity

In this case the culprit is iron ingestion. Iron toxicity classically has five stages, which is somewhat unimportant to the prehospital provider but gives insight into just how dangerous iron can be.

• Stage 1 (0–6 hours): GI symptoms;
• Stage 2 (6–24 hours): Latent period, no symptoms;
• Stage 3 (12–48 hours): Shock, anion gap metabolic acidosis, lactic acidosis;
• Stage 4 (24–96 hours): Fulminant hepatic failure;
• Stage 5 (weeks later): GI mucosal healing leads to scarring and bowel obstruction.

Early signs of iron toxicity include gastrointestinal complaints such as abdominal pain, nausea, and vomiting. These symptoms resolve, leading to a silent period where children may have no symptoms at all. As iron disables cellular mechanisms, organ failure appears within 12–24 hours. Hepatic failure comes first, followed by multiorgan failure and life-threatening acidosis.

It’s important to know which iron formulation was ingested, as this is key to understanding the dose affecting the child. For example, 200 mg of ferrous sulfate contains 65 mg of elemental iron; 300 mg of ferrous gluconate contains 35 mg.

Here’s a rough way to remember how much elemental iron is contained in common iron preparations. In addition, you should note if the iron is formulated for sustained release.

• Ferrous gluconate is good: 10 mg of elemental iron for every 100 mg ingested.
• Ferrous sulfate is so-so: 20 mg of elemental iron for every 100 mg ingested.
• Ferrous fumerate is f— (you get the idea): 30 mg of elemental iron for every 100 mg ingested.

Asymptomatic children who consumed less than 30 mg/kg of elemental iron do not require further workup or hospitalization.

In the field there is little that can be done for iron toxicity other than good ol’ supportive care, such as airway protection, treatment of hypoxemia and hypotension, and transport to a hospital. Unfortunately, activated charcoal does not bind to iron and plays no role in iron overdose.

Back to the Case

Suspecting a toxic overdose, you ask the daycare staff and parents if the child could have ingested any pills. After initially asserting that was impossible, the father remembers both his parents are on numerous medications. He asks his mother for a cell phone photo of her current pills. They show ferrous fumerate iron pills prescribed for her anemia.

ED staff x-ray the child to look for pills. They find no bezoar, and the child is admitted for serial blood iron measurement and observation. While awaiting a serum iron level, the emergency doctor speaks with the poison control toxicologist and pediatrician. You listen in, anticipating that you may have to transport the child to a pediatric ER.

In serious overdose, endoscopic removal of iron tablets, gastric lavage, and whole bowel irrigation may be considered. An antidote, deferoxamine (aka desferrioxamine, Desferal), can be considered for patients with iron levels greater than 90 μmol/l. Deferoxamine chelates free iron into a complex excreted in the urine, turning the urine a pinkish color. In renal failure this complex can be dialyzed.

Repeat iron levels are elevated, but the child improves after a second fluid bolus. She is transferred to a pediatric hospital for observation and potential ICU admission. Fortunately, the next day her iron levels decrease, and she seems better. She avoids the ICU and is discharged the next day without complications.

After a decade working as a helicopter paramedic, Blair Bigham, MD, MSc, EMT-P, completed medical school in Ontario, Canada, where he is now a resident physician in the emergency department. He has authored over 30 scientific articles, led major national projects to advance prehospital research and participated in multiple collaboratives, including the Resuscitation Outcomes Consortium.