Plasma cholinesterase: double-edged parameter in the diagnosis of acute organophosphorus poisoning.

Biochemical markers are one of the mainstays in the diagnosis of ill health. Plasma cholinesterase is one such marker of the ill health caused by acute organophosphorus pesticide poisoning. Organophosphorus pesticides are powerful inhibitors of plasma cholinesterase; consequently, the reduced level of this biochemical marker has been used in the diagnosis of cases of acute poisoning. But how dependable is this biochemical marker in the diagnosis of suspected organophosphorus pesticide poisoning without adequate clinical signs and symptoms? In the case reported here, the low level of plasma cholinesterase which was suspected to be due to organophosphorus poisoning was found to be caused by pulmonary Koch's and hepatitis B with associated malnutrition.