Case Definition: Toxic Alcohols

Clinical description

Ingestion of toxic alcohols (methanol, ethylene glycol, or other glycols) might result in some signs and symptoms similar to those of ethanol inebriation (vomiting, lethargy, or coma). Ingestion of large amounts of a toxic alcohol typically results in a large osmol gap followed by a high anion gap metabolic acidosis. Renal failure is common after ethylene glycol and diethylene glycol toxicity, whereas optic neuritis and visual impairment are seen with methanol toxicity (1-5). Although reference laboratories may provide a “normal” reference range for an osmol gap, poisoning can still occur and depends on multiple factors such as the patient’s baseline (pre-exposure) osmol gap and time elapsed since exposure. Therefore, a “normal” osmol gap should never be used to exclude a toxic alcohol poisoning.

Laboratory criteria for diagnosis

• Biologic: A case in which glycols or methanol and/or their metabolites in whole blood and/or urine is detected, as determined by hospital or commercial laboratory tests. (1-2)

- OR-

• Environmental: Detection of glycols or methanol in environmental samples. (6-9)

Case classification

• Suspected: A case in which a potentially exposed person is being evaluated by health-care workers or public health officials for poisoning by a particular chemical agent, but no specific credible threat exists.
• Probable: A clinically compatible case in which a high index of suspicion (credible threat or patient history regarding location and time) exists for toxic alcohol exposure, or an epidemiologic link exists between this case and a laboratory-confirmed case.
• Confirmed: A clinically compatible case in which laboratory tests have confirmed exposure.

The case can be confirmed if laboratory testing was not performed because either a predominant amount of clinical and nonspecific laboratory evidence of a particular chemical is present or a 100% certainty of the etiology of the agent is known.

Additional resources

1. Weiner SW. Chapter 107: Toxic Alcohols. In: Nelson LS, Lewin NA, Howland MA, et al. (eds). Goldfranks Toxicologic Emergencies. 9th ed. New York, NY: McGraw-Hill; 2011:1400-1410.
2. Barceloux DG, Krenzelok EP, Olson K, Watson W. American Academy of Clinical Toxicology practice guidelines on the treatment of ethylene glycol poisoning. J Toxicol Clin Toxicol 1999;37:537-60.
3. Brent J, McMartin K, Phillips S, et al. Fomepizole for the treatment of ethylene glycol poisoning: methylpyrazole for toxic alcohols study group. N Engl J Med 1999;30:832-8.
4. Hanif M, Mobarak MR, Ronan A, Ralman D, Donovan JJ Jr, Bennish ML. Fatal renal failure caused by diethylene glycol in paracetamol elixir: the Bangladesh epidemic. BMJ 1995;311:88-91.
5. Brent J. Fomepizole for ethylene glycol and methanol poisoning. New Engl J Med. 2009 May 21; 360 (21): 2216-23.
6. NIOSH. NIOSH manual of analytical methods [online]. 2003. [cited 2013 Apr 5]. Available from URL: http://www.cdc.gov/niosh/docs/2003-154/.
7. OSHA. Sampling and analytical methods [online]. 2010. [cited 2013 Apr 5]. Available from URL: http://www.osha.gov/dts/sltc/methods/index.html.
8. FDA. Food: Laboratory methods [online]. 2013. [cited 2013 Apr 5]. Available from URL: http://www.fda.gov/Food/FoodScienceResearch/LaboratoryMethods/default.htm.
9. EPA. Selected analytical methods: chemical methods query [online]. 2013. [cited 2013 Apr 5]. Available from URL: http://www.epa.gov/sam/searchchem.htm.