Ricin Exposure Differential Diagnoses

Updated: May 04, 2017
  • Author: Ferdinando L Mirarchi, DO, FAAEM, FACEP; Chief Editor: Zygmunt F Dembek, PhD, MPH, MS, LHD  more...
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DDx

Diagnostic Considerations

Diagnosis of an aerosolized attack or food and water contamination with ricin is similar to that of an attack with any of the biologic or chemical agents that serve as weapons of mass destruction (WMDs). It primarily depends on the clinical and epidemiologic setting. In cases of isolated injection, the diagnosis is extremely difficult.

The clinical presentation of acute lung injury in a large number of patients in a particular area should suggest a pulmonary irritant. The clinical presentation of severe gastroenteritis or hemorrhagic gastroenteritis in a large number of patients in a particular area should suggest a food and water contaminant.

Several other agents (eg, staphylococcal enterotoxin B, Q fever, tularemia, pneumonic plague, inhalational anthrax, chemical agents such as phosgene) should be included in the differential diagnosis.

Ricin poisoning is expected to progress despite antibiotic therapy. Chest radiography reveals no evidence of mediastinitis, as would be expected with pulmonary anthrax. Staphylococcal enterotoxin B does not progress to a life-threatening syndrome, and phosgene produces acute respiratory distress syndrome (ARDS), which is mediated by exertion. Phosgene also has the characteristic odor of newly mown hay or grass and is moderately water soluble but may be quite irritating to mucous membranes in higher concentrations.

In addition to the conditions listed in the differential diagnosis, other problems to be considered include the following:

  • Cholera
  • Necrotizing fasciitis
  • Pyrolysis byproducts of Teflon, Kevlar
  • Paraquat
  • Acute inorganic mercury, thallium, or iron ingestion
  • Acute radiation sickness
  • Chemotherapeutic drugs
  • Capillary leak syndromes (eg, autoimmune vasculitis and Stevens-Johnson syndrome [SJS])
  • Pneumonia
  • Myocardial infarction
  • Plague
  • Salmonella infection
  • Shigella infection
  • Streptococcus aurea infection
  • Undifferentiated sepsis

Differential Diagnoses