Organophosphate Toxicity Differential Diagnoses

Updated: Mar 13, 2023
  • Author: Kenneth D Katz, MD, FAAEM, ABMT; Chief Editor: Sage W Wiener, MD  more...
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Diagnostic Considerations

Although organophosphate toxicity results in decreased cholinesterase, falsely depressed levels of red blood cell cholinesterase can be found in the following cases:

  • Pernicious anemia
  • Hemoglobinopathies
  • Use of antimalarial drugs
  • Blood collection tubes containing oxalate

Falsely depressed levels of plasma cholinesterase are observed in the following cases:

  • Liver dysfunction
  • Low-protein conditions
  • Neoplasia
  • Hypersensitivity reactions
  • Use of certain drugs (eg, succinylcholine, codeine, morphine)
  • Pregnancy
  • Genetic deficiencies

Other problems to be considered in the differential diagnosis of organophosphate toxicity include the following:

  • Carbamate toxicity
  • Nicotine toxicity
  • Carbachol toxicity
  • Methacholine toxicity
  • Arecoline toxicity
  • Bethanechol toxicity
  • Pilocarpine toxicity
  • Pyridostigmine toxicity
  • Neostigmine toxicity
  • Mushroom poisoning ( Clitocybe, Inocybe)
  • Poison hemlock ( Conium maculatum)poisoning
  • Myasthenia gravis
  • Eaton-Lambert syndrome
  • Guillain-Barré syndrome
  • Botulism
  • Eclampsia

Differential Diagnoses