Thallium Poisoning: Case Report and Scoping Review on Diagnostic Delay and Therapeutic Outcome

Featured Application: Early treatment of suspected cases of thallium intoxication with Prussian Blue is recommended as an “ex juvantibus” strategy, because it offers immediate clinical benefit in positive cases and has negligible side effects in non-intoxicated cases. Thallium poisoning, which may be accidental or criminal, presents with a non-specific clinical picture but is rapidly progressive. A delay in diagnosis may cause the appearance of serious, often irreversible, and sometimes fatal lesions. Prompt treatment with Prussian Blue before toxicological confirmation results in immediate improvement in cases of intoxication, without appreciable side effects, and is, therefore, recommended as an “ex juvantibus” strategy in cases of suspected thallium poisoning. A successfully treated case of poisoning is presented as an example of this strategy. An analysis of the contaminated well water the patient had unknowingly drunk subsequently showed pollution over 75 times higher than the potable limit, and plasma levels revealed values 267 times higher than the normal range. All the test results were received when the patient undergoing treatment had improved so much that she had been discharged from hospital. To complete the study, we conducted a scoping review to understand the extent and type of evidence in relation to the latency in the diagnosis of intoxication and health effects. The review of 30 articles covering 115 cases of thallotoxicosis confirmed that early treatment with Prussian Blue offers the best chance of achieving complete recovery.