# Thallium Poisoning: Case Report and Scoping Review on Diagnostic Delay and Therapeutic Outcome
## 5 Discussion  
### Adverse Effects of Thallium  
Thallium poisoning has a long history and, as we have seen, the occurrence of cases of poisoning cannot be ruled out even in the most advanced countries. The United States ceased the domestic mining of thallium in 1981, but, since then, the growing demand in the semiconductor industry (more than 2 metric tons in 1987) has been met by imports from Belgium (54%), the Netherlands (16%), the Federal Republic of Germany (14%), the United Kingdom (6%), and other sources (10%) [69]. Production was estimated at 14.06 metric tons in the rest of the world [70], and this has caused increasing ecological \begin{table}
\begin{tabular}{c c c} \hline \hline
**Symptoms and Signs** & **Literature Data** & **Our Observation** \\ \hline Paresthesia of the limbs & Reported in all cases & Relief after 2–3 days of treatment with PB. \\ \hline Muscle pain & Reported in all cases & No improvement with ibuprofen. Pain relief 12 h \\  & & after the start of therapy with PB. \\ \hline Chest pain, cardiological signs & Dominant symptoms in cases with late & No improvement with ibuprofen. Disappearance \\  & diagnosis [43, 48, 50] or high dose, criminal & after the therapy with PB. \\ \hline Abdominal pain, nausea, diarrhea & \begin{tabular}{c} Frequently \\ reported [40, 45, 47, 54, 55, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67] \\ \end{tabular} & \begin{tabular}{c} No improvement with ibuprofen. Disappearance \\ after the therapy with PB. \\ \end{tabular} \\ \hline Reduced strength, & \begin{tabular}{c} Frequently reported \\ \end{tabular} & \begin{tabular}{c} Marked relief in 4 days of treatment with PB \\ (discharge). Resumption of household activities after \\ 15 days of treatment. \\ \end{tabular} \\ \hline Generalized asthenia & Frequently reported & Gradual and very slow improvement. \\ \hline Peripheral neuropathy & Very common [40, 41, 42, 43, 44, 46, 47, 48, 50, 52, 53, 54, 55, 56, 57, 58, 59, 61, 63, 65, 66, 67, 68]. & Rapid relief of neurological symptoms \\  & & after treatment. \\ \hline Toxic encephalopathy & In the most serious cases [58, 62, 64] & No. \\ \hline Conjunctival hyperemia, & After high-dose exposure [50, 67] & No improvement with topical preparations. \\  & & Complete relief after treatment with PB. \\ \hline Alopecia & Late onset [34, 42, 47, 48, 52, 56, 57, 58, 59, 60, 61, 63, 68] & Evident 15 days after onset, worsened after 30 days, \\  & & resolved after 120 days of treatment. \\ \hline Skin changes & Late onset [49] & Hyperemia and parakaratosis 15 days after the onset, \\  & & regressed after 30 days. \\ \hline Persistent neurological changes & \
\begin{tabular}{c} Reported in all cases treated with PB \\ more than 10 days after \\ intoxication [40, 43, 47, 50, 52, 54, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68] or \\ after exposure to high doses for criminal \\ intent [42, 56] \\ \end{tabular} & None. \\ \hline Complete recovery & Reported in all cases of early treatment with PB [41, 42, 43, 44, 46, 55] & Complete recovery after 120 days of treatment with PB. \\ \hline Death &
\begin{tabular}{c} Reported in criminal and voluntary \\ cases [42, 53, 56, 58, 62] and in delayed \\ treatment [50, 52] \\ \end{tabular} & No. \\ \hline \hline \end{tabular}  
PB = Prussian Blue.  
\end{table} 
Table 3: Reported symptoms and progression of intoxication as a function of treatment, according to literature data and in our observation. problems globally. Furthermore, thallium is widely distributed in the earth's crust, and this multiplies the possibility that waters are polluted by this element, as was evident in the case reported above. In 2019, the American Association of Poison Control Centers reported 49 single exposures in the US, resulting in one major outcome but no fatalities, which are a rare but not impossible occurrence. Thallium poisoning is prevalent in developing countries; however, few data are available. In this rapid review, we found 115 patients treated with Prussian Blue, 11 of whom had fatal outcomes (Table 2).