Case Definition: Vesicant (Mustards, Dimethyl Sulfate, and Lewisite)

Clinical description

After exposure to vesicants the most common signs and symptoms are dermal (skin erythema and blistering), respiratory (cough, dyspnea, pneumonitis, and acute lung injury), ocular (conjunctivitis and burns), and gastrointestinal (vomiting). Signs and symptoms after exposure to vesicants usually manifest within minutes, except in cases of exposure to sulfur mustard which may result in delayed effects (hours).(1-4).Sulfur mustard also can cause bone marrow suppression resulting in aplastic anemia or pancytopenia .(5)

Laboratory criteria for diagnosis

  • Biologic: A case in which sulfur mustard in biologic samples is detected, as determined by CDC or one of five LRN laboratories that have this capacity, and a case in which nitrogen mustard and lewisite are detected in biologic samples, as determined by CDC.
  • Environmental: Detection of vesicants 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 vesicant exposure, or an epidemiologic link exists between this case and a laboratory-confirmed case.
  • Confirmed: A clinically compatible case in which laboratory tests on biologic samples 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 was present or the etiology of the agent is known with 100% certainty.

Additional resources

  1. Stahl CJ, Green CC, Farnum JB. The incident at Tuol Chrey: pathologic and toxicologic examinations of a casualty after chemical attack. J Forensic Sci 1985;30:317-37.
  2. Borak J, Sidell FR. Agents of chemical warfare: sulfur mustard. Ann Emerg Med 1992;21:303-8.
  3. Sidell FR, Urbanetti JS, Smith WJ, Hurst CG. Vesicants. In: Zajtchuk R, Bellamy RF, eds. Textbook of military medicine: medical aspects of chemical and biologic warfare. Washington, DC: Office of the Surgeon General at TMM Publications, Borden Institute, Walter Reed Army Medical Center ; 1997:197-228.
  4. Siegel D, Younggren BN, Ness B, Kvool V. Operation Castle Cascade: managing multiple casualties from a simulated chemical weapons attack. Mil Med 2003;168:351-4.
  5. Balali-Mood M, Hefazi M. Comparison of early and late toxic effects of sulfur mustard in Iranian veterans. Basic Clin Pharmacol Toxicol 2006;99(4):273-282.
  6. NIOSH. NIOSH manual of analytical methods [online]. 2003. [cited 2013 Apr 5]. Available from URL:
  7. OSHA. Sampling and analytical methods [online]. 2010. [cited 2013 Apr 5]. Available from URL: icon.
  8. FDA. Food: Laboratory methods [online]. 2013. [cited 2013 Apr 5]. Available from URL: icon.
  9. EPA. Selected analytical methods: chemical methods query [online]. 2013. [cited 2013 Apr 5]. Available from URL: icon.
Page last reviewed: April 4, 2018