ARSENIC
MERCURY
LEAD
Remember that metals are caustics.
- Acute arsenic toxicity can present wiht abdominal pain, vomiting, fluid shifts, hemolysis and prolonged QTc.
- Chronic arsenic toxicity leads to peripheral sensory neuropathy, skin hyperpigmentation, Mee's lines and alopecia.
- Arsenic toxicity is associated with lung and skin cancer.
- Testing for arsenic needs a 24 hour urine sample that is speciated and no ingestion of seafood 72 hours prior to testing.
- Treatment is with BAL or succimer.
- Arsine gas classic triad is: abdominal pain, hemolysis and bronze skin.
MERCURY
- Elemental mercury is found in thermometers and is not absorbed by the GI tract, however it is very toxic if it is vaporized.
- Inorganic mercury is associated with renal failure.
- Inorganic mercury has been associated with Pink's disease (acrodynia) with is a maculopapular rash with desquamation and swollen painful extremities.
- Danbury shakes were from mercury used in the felt hat industry leading to chronic toxicity and is where the term "mad as a hatter" comes from.
- Organic mercury crosses the BBB and placenta. It is teratogenic and highly fatal, with neurological demise. Classic finding is constricted visual fields.
- To diagnosis organic mercury toxicity you check a whole blood mercury level.
- To diagnosis inorganic mercury toxicity you check a 24 hour urine mercury level.
- Treatment for inorganic mercury is succimer or BAL.
LEAD
- Lead inhibits multiple steps in the heme pathway.
- Children are more susptible to lead toxicity than adults.
- Lead toxicity can present with a range of symptoms from: constipation, irritability, abdominal pain, tremors, headache, encephalopathy and seizures.
- Diagnosis is made with a whole blood lead level.
- Treatment initially is remove the source then chelate based on the level with BAL, EDTA or succimer.
- Classic lead findings are: basophillic stipling, Burton's lines and lead lines on xrays.
- Iron causes GI symptoms, metabolic acidosis and periportal hepatic necrosis.
- There are various formulations of iron with different percentages of elemental iron.
- There are 5 stages to iron toxicity: 1) GI symptoms, 2) latent 3) Multiorgan failure 4) Hepatic failure 5) Recovery/Long term effects
- Fatal iron poisonings are >60mg/kg
- Iron level after 4 hours if >500mcg/dL need to be treated.
- Deferoxamine should be started for severe acidosis, refractory GI symptoms, shock, altered mental status, or level >500mcg/dL .
- Deferoxamine has been associated with hypotension and Yersinia infections.
- If there are GI symptoms and neurological symptoms think about metal toxicities.
Remember that metals are caustics.