Agency for Toxic Substances and Disease Registry
|
Learning Objectives |
Upon completion of this portion of the case study, the learner should be able to:
|
Conditions that Can be Mimicked by Cholinesterase Inhibitor Toxicity |
In some cases, diagnosis may be difficult, particularly in pediatric cases (Sofer, Tal et al. 1989; Tareg et al. 2001; Erdman 2004) (discussed more later) and the early stages of toxicity when symptoms may be mild and non-specific. (Erdman 2004) In one study, 16 of 20 transferred patients with cholinesterase inhibitor toxicity were misdiagnosed. (Carlton, Simpson et al. 1998) One report on organophosphate poisoning suggested that the most common mistake was to misdiagnose cases presenting with vomiting, diarrhea, and abdominal pain as gastroenteritis. (Hayes, van der Westhuizen et al. 1978) Some examples of conditions that could be mimicked by cholinesterase inhibitor poisoning are shown in the table below. |
Cholinesterase Inhibitor Clinical Finding(s) | Condition(s) Mimicked |
---|---|
|
Viral respiratory infection (common “cold”) (Gaon and Werne 1955) |
|
Influenza (Carlton, Simpson et al. 1998) |
|
Mental illness (Gershon and Shaw 1961) |
|
Diabetic ketoacidosis (Clark 2002) |
|
Gastroenteritis, food poisoning (Tareg et al. 2001) |
|
Pneumonia (Perrone, Henretig et al. 2003), meningitis |
|
Myasthenia crisis, (Erdman 2004); Guillain-Barré syndrome (Tareg et al. 2001) |
|
Nicotine poisoning (Erdman 2004) |
|
Cholinergic drug (e.g., pilocarpine, carbachol, bethanechol, or methacholine) overdose (Erdman 2004) |
|
Opiate overdose, pontine infarction (Tareg et al. 2001) |
|
Intoxication, (Reigart and Roberts 1999) brain injury (Wyckoff, Davies et al. 1968) |
|
Hypertensive encephalopathy (Wyckoff, Davies et al. 1968) |
|
Asthma attack (Tareg et al. 2001) |
|
Hydrocarbon ingestion with aspiration pneumonia (Clark 2002) |
|
Coronary ischemia, myocardial infarction, congestive heart failure, or cardiogenic shock |
|
Severe pyrethroid insecticide* toxicity (Holland 2002) |
* Misdiagnosing this for cholinesterase inhibitor poisoning could lead one to mistakenly administer toxic doses of atropine. (The treatment of pyrethroid poisoning is benzodiazepines or Phenobarbital for seizures, together with supportive care.) (Holland 2002) |
Differential Diagnosis |
Several findings can help differentiate cholinesterase inhibitor toxicity from other conditions:
|
Key Points |
|
Progress Check |