DD in alcohol poisoning

Q: 34 years old patient presents with known ingested alcohol at home. Which of the following toxins may cause cranial nerve palsies and tetany? - select one

A) Ethylene glycol 

B) Methanol 

Answer: A

There is usually no luxury of time in initiating alcohol management. History and clinical exam play a vital role in determining the actual type of alcohol toxicity, particularly if sophisticated, reliable, or fast labs are not available, like in free-standing Emergency Rooms (ERs) and Urgent Cares. 

Cranial nerve palsies and tetany are almost exclusively limited to ethylene glycol toxicity and occur due to oxalate-induced hypocalcemia.

Similarly, an afferent pupillary defect is almost always due to advanced methanol poisoning and demonstrates mydriasis, a retinal sheen (a glossy or metallic reflex) due to retinal edema, and hyperemia of the optic disk.

#toxicity

#physical-exam

#differential-diagnosis

References:

1. Cohen ET, Su MK, Biary R, Hoffman RS. Distinguishing between toxic alcohol ingestion vs alcoholic ketoacidosis: how can we tell the difference? Clin Toxicol (Phila). 2021 Aug;59(8):715-720. doi: 10.1080/15563650.2020.1865542. Epub 2021 Jan 21. PMID: 33475435.

2. Leth PM, Gregersen M. Ethylene glycol poisoning. Forensic Sci Int. 2005 Dec 20;155(2-3):179-84. doi: 10.1016/j.forsciint.2004.11.012. Epub 2005 Jan 21. PMID: 16226155.

3. Alrashed M, Aldeghaither NS, Almutairi SY, Almutairi M, Alghamdi A, Alqahtani T, Almojathel GH, Alnassar NA, Alghadeer SM, Alshehri A, Alnuhait M, Almohammed OA. The Perils of Methanol Exposure: Insights into Toxicity and Clinical Management. Toxics. 2024 Dec 20;12(12):924. doi: 10.3390/toxics12120924. PMID: 39771139; PMCID: PMC11728796.