A metalloid with industrial use in glass, wood preservative, herbicide, semiconductor manufacture, and as an alloy additive. It may be a component in alternative or traditional remedies both intentionally and as a contaminant. Common in the environment and in food, especially seafood, arsenic is odourless and tasteless and highly toxic by ingestion, inhalation and skin contact. It binds to sulphydryl groups inhibiting the action of many enzymes (see ENZYME) and also disrupts oxidative phosphorylation by substituting for PHOSPHORUS. Clinical eﬀects of acute poisoning range from severe gastrointestinal eﬀects to renal impairment or failure characterised by OLIGURIA, HAEMATURIA, PROTEINURIA and renal tubular necrosis. SHOCK, COMA and CONVULSIONS are reported, as are JAUNDICE and peripheral NEUROPATHY. Chronic exposures are harder to diagnose as eﬀects are non-speciﬁc: they include gastrointestinal disturbances, hyperpigmentation and HYPERKERATOSIS of skin, localised OEDEMA, ALOPECIA, neuropathy, PARAESTHESIA, HEPATOMEGALY and jaundice. Management is largely supportive, particularly ensuring adequate renal function. Concentrations of arsenic in urine and blood can be measured and therapy instituted if needed. Several CHELATING AGENTS are eﬀective: these include DMPS (2, 3-dimercapto-1-propanesulphonate), penicillamine and dimercaprol; DMPS is now agent of choice.
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