Ricin Exposure Workup

Updated: May 27, 2021
  • Author: Ferdinando L Mirarchi, DO, FAAEM, FACEP; Chief Editor: Zygmunt F Dembek, PhD, MS, MPH, LHD  more...
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Approach Considerations

In the face of credible threats, clinicians should consider ricin poisoning in patients who present with gastrointestinal (GI) or respiratory illness. Efforts should be made to notify poison control centers, public health, and local law enforcement agencies. Clinicians must have a low threshold of suspicion for patients who present with nonspecific systemic illness, especially when a large number of patients with similar symptoms are present.


Laboratory Studies

Baseline laboratory information should be obtained. Useful tests include the following:

  • Complete blood count (CBC) with differential

  • Blood typing and screening

  • Electrolytes

  • Blood urea nitrogen (BUN) and creatinine

  • Glucose

  • Amylase and lipase

  • Liver function tests (LFTs)

  • Lactic acid

  • Blood, urine, and sputum culture

Coagulation studies (eg, prothrombin time [PT], activated partial thromboplastin time [aPTT], international normalized ratio [INR], and fibrinogen) may be necessary if the gastroenteritis becomes hemorrhagic.

Critically ill and hypotensive patients and those that meet criteria for the systemic inflammatory response syndrome (SIRS) or sepsis should have arterial blood gas (ABG) values and cortisol levels measured. Arterial blood gas studies may reveal hypoxemia.

An enzyme-linked immunoassay (ELISA) can detect ricin in human urine and serum at concentrations of 100 pg/mL or higher. Testing for ricin can be done at a regional public health center laboratory by performing a polymerase chain reaction (PCR) assay on 25 mL of urine. Acute and convalescent serum may be collected to determine measurements of antibody response.

Additional analytic methods may be available for ricin detection through the US Army Medical Research Institute for Infectious Diseases and the Centers for Disease Control and Prevention (CDC).


Other Studies

Chest radiography

In general, imaging studies are not necessary, because the beans generally are not detectable by means of plain radiography. However, a chest radiograph may reveal infiltrates or a picture suggestive of acute respiratory distress syndrome (ARDS). Radiography may also be useful in parenteral exposures to evaluate for a retained foreign body.


If bronchoscopy is performed, the bronchial aspirate may be rich in protein when compared to plasma, as is observed in any condition causing high-permeability pulmonary edema.