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thallium poisoning
Epidemiology:
- used in the manufacture of electronic components optical lenses, semiconductor materials, alloys, gamma radiation detection equipment, imitation jewelry, artist's paints, low temperature thermometers, & green firework
- trace amounts of Tl-201 are used in myocardial perfusion & viability scintigraphy
- thallium exposure may occur at smelters in the maintenance & cleaning of ducts & flues
- contamination of cocaine, heroin, & herbal products
Pathology:
- can be absorbed through the skin, ingested or inhaled
- ingestion of 1 gram or 8 mg/kg is toxic
- Tl+ mimicks K+ but additionally binds thiols
- riboflavin sequestration
- inhibits pyruvate kinase & succinate dehydrogenase
- impaired glucose metabolism
- disruption of the Kreb cycle
- ribosomal inhibition
- myelin sheath injury
Clinical manifestations:
- nausea, vomiting, & diarrhea within 48 hours of exposure
- within a few days, pain, headaches, peripheral neuropathy
- alopecia
- most common & classic manifestation of thallium toxicity
- occurs 7-12 days after the initial onset of symptoms
- after 2-3 weeks alopecia occurs
- Mees lines appear within 2-4 weeks
- painful ascending peripheral neuropathy
- paresthesia, numbness, loss of reflexes, muscle wasting, dysarthria, blurred vision, ataxia, memory impairment, psychosis, seizures, coma can occur
Laboratory:
- complete blood count (CBC)
- anemia, leukocytosis, eosinophilia have been reported after thallium exposure
- comprensive metabolic panel
- electrolyte & glucose abnormalities, hypocalcemia, & impaired renal function & liver function have been reported after thallium exposure
- thallium in blood
- thallium in 24 hour urine
- pregnancy test for all women of child-bearing age [3]
Special laboratory:
- electrocardiogram may show tachyarrhythmia
- nerve conduction studies
- axonal sensorimotor peripheral neuropathy
- nerves innervating the feet most affected
- electromyography [4]
- electroencephlogram may show nonspecific slow-wave activity in severe cases
- electroretinogram
- delayed visual evoked response
- changes tend to occur before clinical symptoms Radiography:
- abdominal radiograph may reveal thallium metal after ingestion (thallium is radiopaque)
Management:
- ABCs
- oxygen as necessary
- intravenous access
- remove contaminated clothing as soon as possible
- avoid self-exposure & wear protective clothing appropriate to the type & degree of contamination
- wear air-purifying or supplied-air respiratory equipment as necessary
- goals
- initial stabilization
- prevention of absorption
- enhanced elimination
- antidotal therapy
- activated charcoal should be considered in patients presenting within 1 hour of ingestion with an intact or protected airway
- whole-bowel irrigation with polyethylene glycol electrolyte lavage solution may be useful
- potassium ferrihexacyanoferrate (Prussian blue, Radiogardase)
- hemodialysis may be useful early prior to tissue distribution
Related
thallium [Tl]
General
toxicity; poisoning; overdose
References
- Wikipedia: Thallium poisoning
http://en.wikipedia.org/wiki/Thallium_poisoning
- Facts About Thallium Poisoning
http://www.medicinenet.com/script/main/art.asp?articlekey=79810
- Duabert GP
eMedicine (Medscape): Thallium Toxicity
http://emedicine.medscape.com/article/821465-overview
- Harmon J, Kapitanyan R
Poisoning Clues on the Skin: 10 Cases
Medscape. April 6, 2017
http://reference.medscape.com/features/slideshow/acutepoisonings