Poison Awareness Month: Zinc Toxicosis

Hey, Zoners

Welcome to March madness. I know it's been quite a while since I wrote a full blog but being poison prevention awareness month I decided that I was going to get back into blogging and start talking about some conditions that we see all the time as technicians. To kick things off we are going to talk about zinc toxicosis.

Yes, many of us may not know that zinc is a normal part of the synthesis of many enzymes but too much can be dangerous to our patients. Zinc toxicosis usually occurs as a result of dietary indiscretion, primarily the consumption of coins, specifically pennies, minted after 1982. The US minted coins contain about 97% zinc. Zinc toxicosis can also occur due to over-supplementation (rare) or the accidental ingestion of items containing a large amount of zinc.

The consumption of U.S pennies minted after 1982 by our patient population can cause irritation and GI ulceration. After prolonged exposure to the pH in the stomach, the free zinc then creates a zinc salt that is then absorbed by the mucosa of the small intestines and distributed into the bloodstream causing damage to multiple organs including the red blood cells, kidneys, and liver.

Clinical signs I was doing toxicity can be nonspecific and initial phases to include vomiting diarrhea weight loss lethargy. This can then progress to GI upset and ulceration followed by melanoma with continued prolonged exposure the patient can present with intravascular hemolysis, anemia, hemoglobinemia and hemoglobinuria, icterus, pancreatitis, liver, and kidney failure.

Diagnosis is mainly based on patient history, my chemical abnormalities, and diagnostic imaging confirmation of a metallic foreign body. These patients can be anemic, have leukocytosis, neutrophilia with a left shift, elevated liver and kidney values, proteinuria, bilirubinuria, plus or minus elevation in their coagulation tests. Diagnostic testing can include trace metal testing but limitations include sample handling specifications, processing, and turnaround time for results. The sample is usually obtained in a navy blue top tube and processed as requested by the reference laboratory. Diagnostic imaging including abdominal radiography can confirm the presence of a metallic foreign body. With a clinical suspicion of a metallic foreign body, the lack of foreign materials on the radiographs does not eliminate zinc toxicity as a possible cause of your clinical signs.

Treatment includes the use of supportive care medications specifically supporting the GI tract with the use of antacids proton pump inhibitors sucralfate and other GI supportive medications. Additionally, depending on the severity of the anemia, a blood transfusion may be required. The immediate removal of the foreign body material when it's safe for the patient is the best course of treatment for those with a strong suspicion or confirmation of a gastrointestinal metallic foreign body. The immediate removal of the source of the trace element will help to minimize and eliminate any additional complications or progression of the toxicity.

The overall prognosis is good with the removal of the inciting agent and supportive care treatments as needed for clinical signs until the patient is stable enough to go home.