Para-dichlorobenzene toxicity – a review of potential neurotoxic manifestations

Abstract

PDCB and other aromatic hydrocarbons are capable of CNS tissue damage and in promoting functional neurological decline. While very little is currently known about prevalence of PDCB addiction, it cannot be ruled out that its illicit use among young people is under-recognized. The number of cases of PDCB toxicity might also rise due to the increasing industrial and domestic use of this chemical.

Clinical Reasoning: A 12-year-old girl with headache and change in mental status

“…Novel approaches have been proposed as potential therapeutic adjuncts, including IV lipid emulsion (ILE) infusion to enhance removal of highly lipophilic PDCB from brain, and acceleration of hepatic metabolism of PDCB with cytochrome P450-inducing agents such as acetaminophen. 5 However, we believed that these approaches posed potential risks, such as transiently accelerating toxin release from peripheral adipose tissue stores with ILE therapy and exacerbating potential toxicity of some PDCB metabolites with P450 inducing agents. After much deliberation, and in the context of clinical improvement, we decided to forgo trials of experimental therapies in our patient.…”

“…Some studies suggest oxidative injury as a mechanism of toxicity of PDCB and some of its metabolites. 5,6 Pathology, in this case, may provide insight into the underlying pathophysiology of brain injury in PDCB exposure. Reactive astrocytosis is a nonspecific finding and can be seen in a variety of toxic injuries.…”

“…This progressive CNS deterioration in PDCB toxicity is believed to reflect a slow release of the neurotoxin from adipose tissues over time with exacerbations during periods of stress or starvation 5 presenting as an acute on chronic neurologic decline. Interestingly, our patient did have acceleration of neurologic decline following a 40-pound weight loss while intubated in the intensive care unit as well as while fasting for surgical procedures.…”

“…5,6 It is a highly volatile compound with a distinctive odor, and is a common indoor air contaminant, resulting in widespread low-level human exposure. PDCB is well-absorbed by ingestion and inhalation, and then rapidly distributed, accumulating primarily in adipose tissue, as well as additional lipophilic sites including the CNS.…”

Halide anions are formed from reactions between atomic metal anions and halogenated aromatic molecules

“…Benzene derivatives are used extensively in industry as solvents, pesticides or intermediate in the synthesis of dyes and explosives. Chlorinated benzenes are toxic compounds that cause immunological disorders affecting the liver, kidney, thyroid, lung, central nervous system and porphyria . Bromobenzene causes necrosis in the liver and kidney .…”